[1] K S Novoselov, A K Geim, S V Morozov. Electric field effect in atomically thin carbon films. Science, 306, 666-669(2004).

[2] J W You, S R Bongu, Q Bao. Nonlinear optical properties and applications of 2D materials: theoretical and experimental aspects. Nanophotonics, 8, 63-97(2018).

[3] Q Yun, L Li, Z Hu. Layered transition metal dichalcogenide-based nanomaterials for electrochemical energy storage. Adv Mater, 32, 1903826(2019).

[4] F Hu, Z Fei. Recent progress on exciton polaritons in layered transition-metal dichalcogenides. Adv Opt Mater, 1901003(2019).

[5] K Cho, J Pak, S Chung. Recent advances in interface engineering of transition-metal dichalcogenides with organic molecules and polymers. ACS Nano, 13, 9713-9734(2019).

[6] G Li, Y Li, H Liu. Architecture of graphdiyne nanoscale films. Chem Commun, 46, 3256-3258(2010).

[7] Y Li, L Xu, H Liu. Graphdiyne and graphyne: from theoretical predictions to practical construction. Chem Soc Rev, 43, 2572-2586(2014).

[8] Z Jia, Y Li, Z Zuo. Synthesis and properties of 2D carbon—graphdiyne. Acc Chem Res, 50, 2470-2478(2017).

[9] L Wu, Y Dong, J Zhao. Kerr nonlinearity in 2D graphdiyne for passive photonic diodes. Adv Mater, 31, 1807981(2019).

[10] Y Dong, Y Zhao, Y Chen. Graphdiyne-hybridized n-doped TiO₂ nanosheets for enhanced visible light photocatalytic activity. J Mater Sci, 53, 8921-8932(2018).

[11] Z Xue, M Zhu, Y Dong. An integrated targeting drug delivery system based on the hybridization of graphdiyne and MOFs for visualized cancer therapy. Nanoscale, 11, 11709-11718(2019).

[12] C Chakraborty, N Vamivakas, D Englund. Advances in quantum light emission from 2D materials. Nanophotonics, 8, 2017-2032(2019).

[13] J D Caldwell, I Aharonovich, G Cassabois. Photonics with hexagonal boron nitride. Nat Rev Mater, 4, 552-567(2019).

[14] K Kanahashi, J Pu, T Takenobu. 2D materials for large-area flexible thermoelectric devices. Adv Energy Mater, 1902842(2019).

[15] K Khan, A K Tareen, M Aslam. Recent advances in two-dimensional materials and their nanocomposites in sustainable energy conversion applications. Nanoscale, 11, 21622-21678(2019).

[16] J Sun, Y Choi, Y J Choi. 2D–organic hybrid heterostructures for optoelectronic applications. Adv Mater, 31, 1803831(2019).

[17] S Lu, C Zhao, Y Zou. Third order nonlinear optical property of Bi₂Se₃. Opt Express, 21, 2072-2082(2013).

[18] Z Guo, H Zhang, S Lu. From black phosphorus to phosphorene: basic solvent exfoliation, evolution of raman scattering, and applications to ultrafast photonics. Adv Funct Mater, 25, 6996-7002(2015).

[19] S B Lu, L L Miao, Z N Guo. Broadband nonlinear optical response in multi-layer black phosphorus: an emerging infrared and mid-infrared optical material. Opt Express, 23, 11183-11194(2015).

[20] R Cao, H D Wang, Z N Guo. Black phosphorous/indium selenide photoconductive detector for visible and near-infrared light with high sensitivity. Adv Opt Mater, 7, 1900020(2019).

[21] C Wang, H Liu, G Bian. Metal-layer assisted growth of ultralong quasi-2D MOF nanoarrays on arbitrary substrates for accelerated oxygen evolution. Small, 15, 1906086(2019).

[22] Y Xue, Q Zhang, W Wang. Opening two-dimensional materials for energy conversion and storage: a concept. Adv Energy Mater, 7, 1602684(2017).

[23] J Pang, R G Mendes, A Bachmatiuk. Applications of 2D MXenes in energy conversion and storage systems. Chem Soc Rev, 48, 72-133(2019).

[24] Z Sun, A Martinez, F Wang. Optical modulators with 2D layered materials. Nat Photonics, 10, 227-238(2016).

[25] M Wang, S Cai, C Pan. Robust memristors based on layered two-dimensional materials. Nat Electron, 1, 130-136(2018).

[26] R Dong, C Lan, F Li, S Yip. Incorporating mixed cations in quasi-2D perovskites for high-performance and flexible photodetectors. Nanoscale Horiz, 4, 1342-1352(2019).

[27] C Anichini, W Czepa, D Pakulski. Chemical sensing with 2D materials. Chem Soc Rev, 47, 4860-4908(2018).

[28] G Iannaccone, F Bonaccorso, L Colombo. Quantum engineering of transistors based on 2D materials heterostructures. Nat Nanotechnol, 13, 183-191(2018).

[29] K S Novoselov, A Mishchenko, A Carvalho. 2D materials and van der Waals heterostructures. Science, 353, aac9439(2016).

[30] R J Shiue, Dmitri K Efetov, G Grosso. Active 2D materials for on-chip nanophotonics and quantum optics. Nanophotonics, 6, 1329-1342(2017).

[31] C C Stoumpos, M G Kanatzidis. Halide perovskites: poor man's high-performance semiconductors. Adv Mater, 28, 5778-5793(2016).

[32] L Wang, H Zhou, J Hu. A Eu³⁺-Eu²⁺ ion redox shuttle imparts operational durability to Pb-I perovskite solar cells. Science, 363, 265-270(2019).

[33] A Kostopoulou, K Brintakis, Nektarios K Nasikas. Perovskite nanocrystals for energy conversion and storage. Nanophotonics, 8, 1607-1640(2019).

[34] N J Jeon, H Na, E H Jung. A fluorene-terminated hole-transporting material for highly efficient and stable perovskite solar cells. Nat Energy, 3, 682-689(2018).

[35] M V Kovalenko, L Protesescu, M I Bodnarchuk. Properties and potential optoelectronic applications of lead halide perovskite nanocrystals. Science, 358, 745-750(2017).

[36] L Dou, A B Wong, Y Yu. Atomically thin two-dimensional organic-inorganic hybrid perovskites. Science, 349, 1518-1521(2015).

[37] B Zhou, D Yan. Simultaneous long-persistent blue luminescence and high quantum yield within 2D organic-metal halide perovskite micro/nanosheets. Angew Chem Int Ed, 58, 15128-15135(2019).

[38] S Lu, Y Ge, Z Sun. Ultrafast nonlinear absorption and nonlinear refraction in few-layer oxidized black phosphorus. Photon Res, 4, 286-292(2016).

[39] Y Song, Y Chen, X Jiang. Nonlinear few-layer MXene-assisted all-optical wavelength conversion at telecommunication band. Adv Opt Mater, 7, 1801777(2019).

[40] A Nayak, J Park, Mey K De. Large hyperpolarizabilities at telecommunication-relevant wavelengths in donor-acceptor-donor nonlinear optical chromophores. ACS Cent Sci, 2, 954-966(2016).

[41] G Li, S Zhang, T Zentgraf. Nonlinear photonic metasurfaces. Nat Rev Mater, 2, 17010(2017).

[42] W Ye, F Zeuner, X Li. Spin and wavelength multiplexed nonlinear metasurface holography. Nat Commun, 7, 11930(2016).

[43] C Xing, G Jing, X Liang. Graphene oxide/black phosphorus nanoflake aerogels with robust thermo-stability and significantly enhanced photothermal properties in air. Nanoscale, 9, 8096-8101(2017).

[44] X Jiang, S Liu, W Liang. Broadband nonlinear photonics in few-layer MXene Ti₃C₂T_x(T = F, O, or OH). Laser Photonics Rev, 12, 1700229(2018).

[45] L Lu, X Tang, R Cao. Broadband nonlinear optical response in few-layer antimonene and antimonene quantum dots: a promising optical kerr media with enhanced stability. Adv Opt Mater, 5, 1700301(2017).

[46] W T Welford. The Principles of Nonlinear Optics. Journal of Modern Optics, 21, 400(1985).

[47] L R Dalton, A W Harper, R Ghosn. Synthesis and processing of improved organic second-order nonlinear optical materials for applications in photonics. Chem Mater, 7, 1060-1081(1995).

[48] B E A Saleh, M C Teich. Fundamentals of photonics~Wiley. Spie Org, 45, 87(2007).

[49] R Zhang, J Fan, X Zhang. Nonlinear optical response of organic–onorganic halide perovskites. ACS Photonics, 3, 371-377(2016).

[50] J Xu, S Semin, T Rasing. Organized chromophoric assemblies for nonlinear optical materials: towards (sub)wavelength scale architectures. Small, 11, 1113-1129(2015).

[51] Bella S Di. Second-order nonlinear optical properties of transition metal complexes. Chem Soc Rev, 30, 355-366(2001).

[52] X Li, S Semin, L A Estrada. Strong optical nonlinearities of self-assembled polymorphic microstructures of phenylethynyl functionalized fluorenones. Chin Chem Lett, 29, 297-300(2018).

[53] J Xu, X Li, J Xiong. Halide perovskites for nonlinear optics. Adv Mater, 32, 1806736(2019).

[54] A Wang, J Ye, M G Humphrey. Graphene and carbon-nanotube nanohybrids covalently functionalized by porphyrins and phthalocyanines for optoelectronic properties. Adv Mater, 30, 1705704(2018).

[55] M Zhao, R Peng, Q Zheng. Broadband optical limiting response of a graphene–PbS nanohybrid. Nanoscale, 7, 9268-9274(2015).

[56] C Zheng, L Lei, J Huang. Facile control of metal nanoparticles from isolated nanoparticles to aggregated clusters on two-dimensional graphene to form optical limiters. J Mater Chem C, 5, 11579-11589(2017).

[57] X Li. Design of novel graphdiyne-based materials with large second-order nonlinear optical properties. J Mater Chem C, 6, 7576-7583(2018).

[58] K Shehzadi, K Ayub, T Mahmood. Theoretical study on design of novel superalkalis doped graphdiyne: A new donor–acceptor (D-π-A) strategy for enhancing NLO response. Appl Surf Sci, 492, 255-263(2019).

[59] J Guo, R Shi, R Wang. Graphdiyne-polymer nanocomposite as a broadband and robust saturable absorber for ultrafast photonics. Laser Photonics Rev, 1900367(2020).

[60] J Shi, P Yu, F Liu. 3R MoS₂ with broken inversion symmetry: a promising ultrathin nonlinear optical Device. Adv Mater, 29, 1701486(2017).

[61] C Quan, C Lu, C He. Band alignment of MoTe₂/MoS₂ nanocomposite films for enhanced nonlinear optical performance. Adv Mater Interfaces, 6, 1801733(2019).

[62] X Tian, R Wei, M Liu. Ultrafast saturable absorption in TiS₂ induced by non-equilibrium electrons and the generation of a femtosecond mode-locked laser. Nanoscale, 10, 9608-9615(2018).

[63] Z Xie, Y Wu, X Sun. Ultra-broadband nonlinear optical response of two-dimensional h-BN nanosheets and their hybrid gel glasses. Nanoscale, 10, 4276-4283(2018).

[64] G Zhao, F Zhang, Y Wu. One-step exfoliation and hydroxylation of boron nitride nanosheets with enhanced optical limiting performance. Adv Opt Mater, 4, 141-146(2016).

[65] Y Xu, XF Jiang, Y Ge. Size-dependent nonlinear optical properties of black phosphorus nanosheets and their applications in ultrafast photonics. J Mater Chem C, 5, 3007-3013(2017).

[66] M Shi, S Huang, N Dong. Donor–acceptor type blends composed of black phosphorus and C₆₀ for solid-state optical limiters. Chem Commun, 54, 366-369(2018).

[67] K Wang, B M Szydłowska, G Wang. Ultrafast nonlinear excitation dynamics of black phosphorus nanosheets from visible to mid-infrared. ACS Nano, 10, 6923-6932(2016).

[68] C Wang, T Zhang, W Lin. Rational synthesis of noncentrosymmetric metal–organic frameworks for second-order nonlinear optics. Chem Rev, 112, 1084-1104(2012).

[69] R J Niu, W F Zhou, Y Liu. Morphology-dependent third-order optical nonlinearity of a 2D Co-based metal–organic framework with a porphyrinic skeleton. Chem Commun, 55, 4873-4876(2019).

[70] J m Shi, W Xu, Q y Liu. Polynitrile-bridged two-dimensional crystal: Eu(lll) complex with strong fluorescence emission and NLO property. Chem Commun, 756-757(2002).

[71] B P Biswal, S Valligatla, M Wang. Nonlinear optical switching in regioregular porphyrin covalent organic frameworks. Angew Chem Int Ed, 58, 6896-6900(2019).

[72] Y Dong, Y Zhang, X Li. Chiral perovskites: promising materials toward next-generation optoelectronics. Small, 15, 1902237(2019).

[73] J Xue, D Yang, B Cai. Photon-induced reversible phase transition in CsPbBr₃ perovskite. Adv Funct Mater, 29, 1807922(2019).

[74] J Hu, L Yan, W You. Two-dimensional organic–inorganic hybrid perovskites: a new platform for optoelectronic applications. Adv Mater, 30, 1802041(2018).

[75] Baena J P Correa, M Saliba, T Buonassisi. Promises and challenges of perovskite solar cells. Science, 358, 739-744(2017).

[76] G Grancini, M K Nazeeruddin. Dimensional tailoring of hybrid perovskites for photovoltaics. Nat Rev Mater, 4, 4-22(2019).

[77] W Li, Z Wang, F Deschler. Chemically diverse and multifunctional hybrid organic-inorganic perovskites. Nat Rev Mater, 2, 16099(2017).

[78] C C Stoumpos, D H Cao, D J Clark. Ruddlesden-popper hybrid lead iodide perovskite 2D homologous semiconductors. Chem Mater, 28, 2852-2867(2016).

[79] O Nazarenko, MR Kotyrba, S Yakunin. Guanidinium-formamidinium lead iodide: a layered perovskite-related compound with red luminescence at room temperature. J Am Chem Soc, 140, 3850-3853(2018).

[80] TM Koh, V Shanmugam, J Schlipf. Nanostructuring mixed-dimensional perovskites: a route toward tunable, efficient photovoltaics. Adv Mater, 28, 3653-3661(2016).

[81] B Saparov, D B Mitzi. Organic-inorganic perovskites: structural versatility for functional materials design. Chem Rev, 116, 4558-4596(2016).

[82] H-D Lee, H Kim, H Cho. Efficient ruddlesden–popper perovskite light-emitting diodes with randomly oriented nanocrystals. Adv Funct Mater, 29, 1901225(2019).

[83] Y Zheng, T Niu, X Ran. Unique characteristics of 2D Ruddlesden–Popper (2DRP) perovskite for future photovoltaic application. J Mater Chem A, 7, 13860-13872(2019).

[84] S Yu, Y Yan, M Abdellah. Nonconfinement structure sevealed in Dion–Jacobson type quasi-2D perovskite expedites interlayer charge transport. Small, 15, 1905081(2019).

[85] L Mao, W Ke, L Pedesseau. Hybrid Dion–Jacobson 2D lead iodide perovskites. J Am Chem Soc, 140, 3775-3783(2018).

[86] Y Li, J V Milić, A Ummadisingu. Bifunctional organic spacers for formamidinium-based hybrid Dion–Jacobson two-dimensional perovskite solar cells. Nano Lett, 19, 150-157(2019).

[87] Y Zhang, P Wang, M C Tang. Dynamical transformation of two-dimensional perovskites with alternating cations in the interlayer space for high-performance photovoltaics. J Am Chem Soc, 141, 2684-2694(2019).

[88] C M M Soe, C C Stoumpos, M Kepenekian. New type of 2D perovskites with alternating cations in the interlayer space, (C(NH₂)₃)(CH₃NH₃)_nPb_nI_3n+1: structure, properties, and photovoltaic performance. J Am Chem Soc, 139, 16297-16309(2017).

[89] L Mao, C C Stoumpos, M G Kanatzidis. Two-dimensional hybrid halide perovskites: principles and promises. J Am Chem Soc, 141, 1171-1190(2019).

[90] I Zimmermann, S Aghazada, M K Nazeeruddin. Lead and HTM free stable two-dimensional tin perovskites with suitable band gap for solar cell applications. Angew Chem Int Ed, 58, 1072-1076(2019).

[91] X Li, J Hoffman, W Ke. Two-dimensional halide perovskites incorporating straight chain symmetric diammonium ions, (NH₃C_mH_2mNH₃)(CH₃NH₃)_n−1Pb_nI_3n+1 (m = 4–9; n = 1–4). J Am Chem Soc, 140, 12226-12238(2018).

[92] H Kim, K A Huynh, S Y Kim. 2D and quasi-2D halide perovskites: applications and progress. Phys Status Solidi RRL, 14, 1900435(2019).

[93] N Wang, L Cheng, R Ge. Perovskite light-emitting diodes based on solution-processed self-organized multiple quantum wells. Nat Photonics, 10, 699-704(2016).

[94] M Yuan, LN Quan, R Comin. Perovskite energy funnels for efficient light-emitting diodes. Nat Nanotechnol, 11, 872(2016).

[95] Z Chen, Y Guo, E Wertz. Merits and challenges of ruddlesden–popper soft halide perovskites in electro-optics and optoelectronics. Adv Mater, 31, 1803514(2019).

[96] Z Yuan, Y Shu, Y Xin. Highly luminescent nanoscale quasi-2D layered lead bromide perovskites with tunable emissions. Chem Commun, 52, 3887-3890(2016).

[97] L Mao, P Guo, M Kepenekian. Structural diversity in white-light-emitting hybrid lead bromide perovskites. J Am Chem Soc, 140, 13078-13088(2018).

[98] L Zhou, J F Liao, Z G Huang. Intrinsic self-trapped emission in 0D lead-free (C₄H₁₄N₂)₂In₂Br₁₀ single crystal. Angew Chem Int Ed, 58, 15435-15440(2019).

[99] D Cortecchia, S Neutzner, Kandada A R Srimath. Broadband emission in two-dimensional hybrid perovskites: the role of structural deformation. J Am Chem Soc, 139, 39-42(2017).

[100] M H Jung. White-light emission from the structural distortion induced by control of halide composition of two-dimensional perovskites ((C₆H₅CH₂NH₃)₂PbBr_4–xCl_x). Inorg Chem, 58, 6748-6757(2019).

[101] L Zhang, L Wu, K Wang. Pressure-induced broadband emission of 2D organic-inorganic hybrid perovskite (C₆H₅C₂H₄NH₃)₂PbBr₄. Adv Sci, 6, 1801628(2019).

[102] X Li, P Guo, M Kepenekian. Small cyclic diammonium cation templated (110)-oriented 2D halide (X = I, Br, Cl) perovskites with white-light emission. Chem Mater, 31, 3582-3590(2019).

[103] D B Mitzi, S Wang, C A Feild. Conducting layered organic-inorganic halides containing <110>-oriented perovskite sheets. Science, 267, 1473-1476(1995).

[104] L Mao, Y Wu, C C Stoumpos. White-light emission and structural distortion in new corrugated two-dimensional lead bromide perovskites. J Am Chem Soc, 139, 5210-5215(2017).

[105] Y Y Li, C K Lin, G L Zheng. Novel <110>-oriented organic−inorganic perovskite compound stabilized by n-(3-aminopropyl)imidazole with improved optical properties. Chem Mater, 18, 3463-3469(2006).

[106] D Cortecchia, J Yin, A Petrozza. White light emission in low-dimensional perovskites. J Mater Chem C, 7, 4956-4969(2019).

[107] Z Wu, C Ji, Z Sun. Broadband white-light emission with a high color rendering index in a two-dimensional organic-inorganic hybrid perovskite. J Mater Chem C, 6, 1171-1175(2018).

[108] E P Booker, T H Thomas, C Quarti. Formation of long-lived color centers for broadband visible light emission in low-dimensional layered perovskites. J Am Chem Soc, 139, 18632-18639(2017).

[109] K M McCall, C C Stoumpos, O Y Kontsevoi. From 0D Cs₃Bi₂I₉ to 2D Cs₃Bi₂I₆Cl₃: dimensional expansion induces a direct band gap but enhances electron–phonon coupling. Chem Mater, 31, 2644-2650(2019).

[110] F Jiang, D Yang, Y Jiang. Chlorine-incorporation-induced formation of the layered phase for antimony-based lead-free perovskite solar cells. J Am Chem Soc, 140, 1019-1027(2018).

[111] Z Liu, X Zhao, A Zunger. Design of mixed-cation tri-layered Pb-free halide perovskites for optoelectronic applications. Adv Electron Mater, 5, 1900234(2019).

[112] B Vargas, E Ramos, E Pérez-Gutiérrez. A direct bandgap copper–antimony halide perovskite. J Am Chem Soc, 139, 9116-9119(2017).

[113] S Chai, J Xiong, Y Zheng. Dielectric phase transition of an A₂BX₄-type perovskite with a pentahedral to octahedral transformation. Dalton Trans, 49, 2218-2224(2020).

[114] E Shi, Y Gao, B P Finkenauer. Two-dimensional halide perovskite nanomaterials and heterostructures. Chem Soc Rev, 47, 6046-6072(2018).

[115] C Huo, B Cai, Z Yuan. Two-dimensional metal halide perovskites: theory, synthesis, and optoelectronics. Small Methods, 1, 1600018(2017).

[116] J Wang, H Shen, W Li. The role of chloride incorporation in lead-free 2D perovskite (BA)₂SnI₄: morphology, photoluminescence, phase transition, and charge transport. Adv Sci, 6, 1802019(2019).

[117] B Hwang, J S Lee. 2D perovskite-based self-aligned lateral heterostructure photodetectors utilizing vapor deposition. Adv Opt Mater, 7, 1801356(2019).

[118] J Chen, Y Wang, L Gan. Generalized self-doping engineering towards ultrathin and large-sized two-dimensional homologous perovskites. Angew Chem Int Ed, 56, 14893-14897(2017).

[119] Z Chen, Y Wang, X Sun. Remote phononic effects in epitaxial Ruddlesden–Popper halide perovskites. J Phys Chem Lett, 9, 6676-6682(2018).

[120] R L Milot, R J Sutton, G E Eperon. Charge-carrier dynamics in 2D hybrid metal–halide perovskites. Nano Lett, 16, 7001-7007(2016).

[121] J Li, J Wang, J Ma. Self-trapped state enabled filterless narrowband photodetections in 2D layered perovskite single crystals. Nat Commun, 10, 806(2019).

[122] H Li, J Lu, T Zhang. Cation-assisted restraint of a wide quantum well and interfacial charge accumulation in two-dimensional perovskites. ACS Energy Lett, 3, 1815-1823(2018).

[123] R Guo, Z Zhu, A Boulesbaa. Synthesis and photoluminescence properties of 2D phenethylammonium lead bromide perovskite nanocrystals. Small Methods, 1, 1700245(2017).

[124] H H Fang, S Adjokatse, S Shao. Long-lived hot-carrier light emission and large blue shift in formamidinium tin triiodide perovskites. Nat Commun, 9, 243(2018).

[125] G Long, C Jiang, R Sabatini. Spin control in reduced-dimensional chiral perovskites. Nat Photonics, 12, 528-533(2018).

[126] J Guan, C Zhang, D Gao. Drastic photoluminescence modulation of an organic molecular crystal with high pressure. Mater Chem Front, 3, 1510-1517(2019).

[127] M D Smith, H I Karunadasa. White-light emission from layered halide perovskites. Acc Chem Res, 51, 619-627(2018).

[128] S Aharon, L Etgar. Two dimensional organometal halide perovskite nanorods with tunable optical properties. Nano Lett, 16, 3230-3235(2016).

[129] Y Cao, N Wang, H Tian. Perovskite light-emitting diodes based on spontaneously formed submicrometre-scale structures. Nature, 562, 249-253(2018).

[130] J W Lee, Z Dai, T H Han. 2D perovskite stabilized phase-pure formamidinium perovskite solar cells. Nat Commun, 9, 3021(2018).

[131] D H Cao, C C Stoumpos, T Yokoyama. Thin films and solar cells based on semiconducting two-dimensional Ruddlesden-Popper (CH₃(CH₂)₃NH₃)₂(CH₃NH₃)_n−1Sn_nI_3n+1 perovskites. ACS Energy Lett, 2, 982-990(2017).

[132] Q Chen, J Wu, X Ou. All-inorganic perovskite nanocrystal scintillators. Nature, 561, 88-93(2018).

[133] J Wang, J Li, S Lan. Controllable growth of centimeter-sized 2D perovskite heterostructures for highly narrow dual-band photodetectors. ACS Nano, 13, 5473-5484(2019).

[134] E R Dohner, A Jaffe, L R Bradshaw. Intrinsic white-light emission from layered hybrid perovskites. J Am Chem Soc, 136, 13154-13157(2014).

[135] F Thouin, D A Valverde-Chávez, C Quarti. Phonon coherences reveal the polaronic character of excitons in two-dimensional lead halide perovskites. Nat Mater, 18, 349-356(2019).

[136] A Yangui, D Garrot, J S Lauret. Optical investigation of broadband white-light emission in self-assembled organic-inorganic perovskite (C₆H₁₁NH₃)₂PbBr₄. J Phys Chem C, 119, 23638-23647(2015).

[137] K Thirumal, W K Chong, W Xie. Morphology-independent stable white-light emission from self-assembled two-dimensional perovskites driven by strong exciton–phonon coupling to the organic framework. Chem Mater, 29, 3947-3953(2017).

[138] L Mao, Y Wu, C C Stoumpos. Tunable white-light emission in single-cation-templated three-layered 2D perovskites (CH₃CH₂NH₃)₄Pb₃Br_10–xCl_x. J Am Chem Soc, 139, 11956-11963(2017).

[139] C Ji, S Wang, L Li. The first 2D hybrid perovskite ferroelectric showing broadband white-light emission with high color rendering index. Adv Funct Mater, 29, 1805038(2019).

[140] B Huang, W C Chen, Z Li. Manipulation of molecular aggregation states to realize polymorphism, AIE, MCL, and TADF in a single molecule. Angew Chem Int Ed, 57, 12473-12477(2018).

[141] Y L Zhang, Q Ran, Q Wang. High-efficiency red organic light-emitting diodes with external quantum efficiency close to 30% based on a novel thermally activated delayed fluorescence emitter. Adv Mater, 31, 1902368(2019).

[142] H Hu, F Meier, D Zhao. Efficient room-temperature phosphorescence from organic–inorganic hybrid perovskites by molecular engineering. Adv Mater, 30, 1707621(2018).

[143] Z An, C Zheng, Y Tao. Stabilizing triplet excited states for ultralong organic phosphorescence. Nat Mater, 14, 685(2015).

[144] Haj Salah M Ben, N Mercier, M Allain. Dual phosphorescence from the organic and inorganic moieties of 1D hybrid perovskites of the Pb_′Br_4n′+2 series (n′= 2, 3, 4, 5). J Mater Chem C, 7, 4424-4433(2019).

[145] O Bolton, K Lee, H J Kim. Activating efficient phosphorescence from purely organic materials by crystal design. Nat Chem, 3, 205-210(2011).

[146] H Zheng, G Liu, L Zhu. The effect of hydrophobicity of ammonium salts on stability of quasi-2D perovskite materials in moist condition. Adv Energy Mater, 8, 1800051(2018).

[147] C Ding, Y Zhang, F Liu. Effect of the conduction band offset on interfacial recombination behavior of the planar perovskite solar cells. Nano Energy, 53, 17-26(2018).

[148] C Yuan, X Li, S Semin. Chiral lead halide perovskite nanowires for second-order nonlinear optics. Nano Lett, 18, 5411-5417(2018).

[149] J Wang, C Fang, J Ma. Aqueous synthesis of low-dimensional lead halide perovskites for room-temperature circularly polarized light emission and detection. ACS Nano, 13, 9473-9481(2019).

[150] C Xing, W Huang, Z Xie. Ultrasmall bismuth quantum dots: facile liquid-phase exfoliation, characterization, and application in high-performance UV–Vis photodetector. ACS Photonics, 5, 621-629(2018).

[151] Z Xie, C Xing, W Huang. Ultrathin 2D nonlayered tellurium nanosheets: facile liquid-phase exfoliation, characterization, and photoresponse with high performance and enhanced stability. Adv Funct Mater, 28, 1705833(2018).

[152] T Fan, Z Xie, W Huang. Two-dimensional non-layered selenium nanoflakes: facile fabrications and applications for self-powered photo-detector. Nanotechnology, 30, 114002(2019).

[153] W Huang, Z Xie, T Fan. Black-phosphorus-analogue tin monosulfide: an emerging optoelectronic two-dimensional material for high-performance photodetection with improved stability under ambient/harsh conditions. J Mater Chem C, 6, 9582-9593(2018).

[154] L Huang, B Dong, X Guo. Waveguide-integrated black phosphorus photodetector for mid-infrared applications. ACS Nano, 13, 913-921(2019).

[155] T M Brenner, D A Egger, L Kronik. Hybrid organic—inorganic perovskites: low-cost semiconductors with intriguing charge-transport properties. Nat Rev Mater, 1, 15007(2016).

[156] X Qi, Y Zhang, Q Ou. Photonics and optoelectronics of 2D metal-halide perovskites. Small, 14, 1800682(2018).

[157] Y Zhang, Y Liu, Z Xu. Two-dimensional (PEA)₂PbBr₄ perovskite single crystals for a high performance UV-detector. J Mater Chem C, 7, 1584-1591(2019).

[158] L Li, Z Sun, P Wang. Tailored engineering of an unusual (C₄H₉NH₃)₂(CH₃NH₃)₂Pb₃Br₁₀ two-dimensional multilayered perovskite ferroelectric for a high-performance photodetector. Angew Chem Int Ed, 56, 12150-12154(2017).

[159] Z Tan, Y Wu, H Hong. Two-dimensional (C₄H₉NH₃)₂PbBr₄ perovskite crystals for high-performance photodetector. J Am Chem Soc, 138, 16612-16615(2016).

[160] L Qian, Y Sun, M Sun. 2D perovskite microsheets for high-performance photodetectors. J Mater Chem C, 7, 5353-5358(2019).

[161] Z Xie, F Zhang, Z Liang. Revealing of the ultrafast third-order nonlinear optical response and enabled photonic application in two-dimensional tin sulfide. Photon Res, 7, 494-502(2019).

[162] L Wu, Z Xie, L Lu. Few-layer tin sulfide: a promising black-phosphorus-analogue 2D material with exceptionally large nonlinear optical response, high stability, and applications in all-optical switching and wavelength conversion. Adv Opt Mater, 6, 1700985(2018).

[163] C Xing, Z Xie, Z Liang. 2D nonlayered selenium nanosheets: facile synthesis, photoluminescence, and ultrafast photonics. Adv Opt Mater, 5, 1700884(2017).

[164] J J Dean, Driel H M van. Graphene and few-layer graphite probed by second-harmonic generation: theory and experiment. Phys Rev B, 82, 125411(2010).

[165] Y Liu, P Gao, T Zhang. Azide passivation of black phosphorus nanosheets: covalent functionalization affords ambient stability enhancement. Angew Chem Int Ed, 58, 1479-1483(2019).

[166] B M Szydłowska, B Tywoniuk, W J Blau. Size-dependent nonlinear optical response of black phosphorus liquid phase exfoliated nanosheets in nanosecond regime. ACS Photonics, 5, 3608-3612(2018).

[167] W Ma, J Lu, B Wan. Piezoelectricity in multilayer black phosphorus for piezotronics and nanogenerators. Adv Mater, 32, 1905795(2020).

[168] J M Skelton, L A Burton, F Oba. Chemical and lattice stability of the tin sulfides. J Phys Chem C, 121, 6446-6454(2017).

[169] C Xin, J Zheng, Y Su. Few-layer tin sulfide: a new black-phosphorus-analogue 2D material with a sizeable band gap, odd–even quantum confinement effect, and high carrier mobility. J Phys Chem C, 120, 22663-22669(2016).

[170] A S Sarkar, A Mushtaq, D Kushavah. Liquid exfoliation of electronic grade ultrathin tin(II) sulfide (SnS) with intriguing optical response. npj 2D Mater Appl, 4, 1(2020).

[171] H Wang, X Qian. Giant optical second harmonic generation in two-dimensional multiferroics. Nano Lett, 17, 5027-5034(2017).

[172] A Ferrando, Pastor J P Martínez, I Suárez. Toward metal halide perovskite nonlinear photonics. J Phys Chem Lett, 9, 5612-5623(2018).

[173] R Dong, T Zhang, X Feng. Interface-assisted synthesis of 2D materials: trend and challenges. Chem Rev, 118, 6189-6235(2018).

[174] D Geng, H Y Yang. Recent advances in growth of novel 2D materials: beyond graphene and transition metal dichalcogenides. Adv Mater, 30, 1800865(2018).

[175] M R Lukatskaya, O Mashtalir, C E Ren. Cation intercalation and high volumetric capacitance of two-dimensional titanium carbide. Science, 341, 1502-1505(2013).

[176] D Lim, H Suh, M Suryawanshi. Kinetically controlled growth of phase-pure SnS absorbers for thin film solar cells: achieving efficiency near 3% with long-term stability using an SnS/CdS heterojunction. Adv Energy Mater, 8, 1702605(2018).

[177] P A Franken, A E Hill, C W Peters. Generation of optical harmonics. Phys Rev Lett, 7, 118-119(1961).

[178] Y Duan, C Ju, G Yang. Aggregation induced enhancement of linear and nonlinear optical emission from a hexaphenylene derivative. Adv Funct Mater, 26, 8968-8977(2016).

[179] J Xu, S Semin, D Niedzialek. Self-assembled organic microfibers for nonlinear optics. Adv Mater, 25, 2084-2089(2013).

[180] T Chervy, J Xu, Y Duan. High-efficiency second-harmonic generation from hybrid light-matter states. Nano Lett, 16, 7352-7356(2016).

[181] R W Boyd, B R Masters. Nonlinear optics, third edition. Journal of Biomedical Optics, 14, 029902(2009).

[182] E Timurdogan, C V Poulton, M J Byrd. Electric field-induced second-order nonlinear optical effects in silicon waveguides. Nat Photonics, 11, 200-206(2017).

[183] J Xu, S Semin, J Cremers. Controlling microsized polymorphic architectures with distinct linear and nonlinear optical properties. Adv Opt Mater, 3, 948-956(2015).

[184] J Xiong, X Li, C Yuan. Wavelength dependent nonlinear optical response of tetraphenylethene aggregation-induced emission luminogens. Mater Chem Front, 2, 2263-2271(2018).

[185] S Wang, Y Yao, J Kong. Highly efficient white-light emission in a polar two-dimensional hybrid perovskite. Chem Commun, 54, 4053-4056(2018).

[186] P P Shi, Y Y Tang, P F Li. Symmetry breaking in molecular ferroelectrics. Chem Soc Rev, 45, 3811-3827(2016).

[187] J Qin, F Huang, X Li. Enhanced second harmonic generation from ferroelectric HfO₂-based hybrid metasurfaces. ACS Nano, 13, 1213-1222(2019).

[188] W Q Liao, Y Zhang, C L Hu. A lead-halide perovskite molecular ferroelectric semiconductor. Nat Commun, 6, 7338(2015).

[189] Z Wu, C Ji, L Li. Alloying n-butylamine into CsPbBr₃ to give a two-dimensional bilayered perovskite ferroelectric material. Angew Chem Int Ed, 57, 8140-8143(2018).

[190] Y Y Tang, P F Li, W Q Liao. Multiaxial molecular ferroelectric thin films bring light to practical applications. J Am Chem Soc, 140, 8051-8059(2018).

[191] L Li, X Liu, Y Li. Two-dimensional hybrid perovskite-type ferroelectric for highly polarization-sensitive shortwave photodetection. J Am Chem Soc, 141, 2623-2629(2019).

[192] S Han, X Liu, Y Liu. High-temperature antiferroelectric of lead iodide hybrid perovskites. J Am Chem Soc, 141, 12470-12474(2019).

[193] C Liu, D Mei, W Cao. Mn-based tin sulfide Sr₃MnSn₂S₈ with a wide band gap and strong nonlinear optical response. J Mater Chem C, 7, 1146-1150(2019).

[194] F Ding, M L Nisbet, H Yu. Syntheses, structures, and properties of non-centrosymmetric quaternary tellurates BiMTeO₆ (M = Al, Ga). Inorg Chem, 57, 7950-7956(2018).

[195] J Chen, C L Hu, F F Mao. A facile route to nonlinear optical materials: three-site aliovalent substitution involving one cation and two anions. Angew Chem Int Ed, 58, 2098-2102(2019).

[196] M E Strayer, A S Gupta, H Akamatsu. Emergent noncentrosymmetry and piezoelectricity driven by oxygen octahedral rotations in n = 2 Dion–Jacobson phase layer perovskites. Adv Funct Mater, 26, 1930-1937(2016).

[197] H G Kim, T T Tran, W Choi. Two new non-centrosymmetric n = 3 layered Dion-Jacobson perovskites: polar RbBi₂Ti₂NbO₁₀ and nonpolar CsBi₂Ti₂TaO₁₀. Chem Mater, 28, 2424-2432(2016).

[198] A S Gupta, H Akamatsu, M E Strayer. Improper inversion symmetry breaking and piezoelectricity through oxygen octahedral rotations in layered perovskite family, LiRTiO₄ (R = rare earths). Adv Electron Mater, 2, 1500196(2016).

[199] W J Wei, X X Jiang, L Y Dong. Regulating second-harmonic generation by van der Waals interactions in two-dimensional lead halide perovskite nanosheets. J Am Chem Soc, 141, 9134-9139(2019).

[200] C K Yang, W N Chen, Y T Ding. The first 2D homochiral lead iodide perovskite ferroelectrics:[R-and S-1-(4-chlorophenyl)ethylammonium]₂PbI₄. Adv Mater, 31, 1808088(2019).

[201] M Savoini, L Huber, H Cuppen. THz generation and detection by fluorenone based organic crystals. ACS Photonics, 5, 671-677(2018).

[202] J Maysonnave, S Huppert, F Wang. Terahertz generation by dynamical photon drag effect in graphene excited by femtosecond optical pulses. Nano Lett, 14, 5797-5802(2014).

[203] A Chanana, Y Zhai, S Baniya. Colour selective control of terahertz radiation using two-dimensional hybrid organic inorganic lead-trihalide perovskites. Nat Commun, 8, 1328(2017).

[204] P Weis, J L Garcia-Pomar, M Hh. Spectrally wide-band terahertz wave modulator based on optically tuned graphene. ACS Nano, 6, 9118-9124(2012).

[205] A S Haynes, F O Saouma, C O Otieno. Phase-change behavior and nonlinear optical second and third harmonic generation of the one-dimensional K_(1−x)Cs_xPSe₆ and metastable β-CsPSe₆. Chem Mater, 27, 1837-1846(2015).

[206] S Deckers, J Steverlynck, P Willot. Regioregularity increases second-order nonlinear optical response of polythiophenes in solution. J Phys Chem C, 119, 18513-18517(2015).

[207] F O Saouma, C C Stoumpos, J Wong. Selective enhancement of optical nonlinearity in two-dimensional organic-inorganic lead iodide perovskites. Nat Commun, 8, 742(2017).

[208] E Hanamura, N Nagaosa, M Kumagai. Quantum wells with enhanced exciton effects and optical non-linearity. Mater Sci Eng, B, 1, 255-258(1988).

[209] I Abdelwahab, G Grinblat, K Leng. Highly enhanced third-harmonic generation in 2D perovskites at excitonic resonances. ACS Nano, 12, 644-650(2018).

[210] N Youngblood, R Peng, A Nemilentsau. Layer-tunable third-harmonic generation in multilayer black phosphorus. ACS Photonics, 4, 8-14(2017).

[211] Z Wei, D Guo, J Thieme. The importance of relativistic effects on two-photon absorption spectra in metal halide perovskites. Nat Commun, 10, 5342(2019).

[212] F Zhou, I Abdelwahab, K Leng. 2D perovskites with giant excitonic optical nonlinearities for high-performance sub-bandgap photodetection. Adv Mater, 31, 1904155(2019).

[213] W F Zhang, Y B Huang, M S Zhang. Optical properties of ferroelectric (Pb, La)(Zr, Ti)O₃ thin films grown by pulsed laser deposition. Appl Surf Sci, 158, 185-189(2000).

[214] W Liu, X Li, Y Song. Cooperative enhancement of two-photon-absorption-induced photoluminescence from a 2D perovskite-microsphere hybrid dielectric structure. Adv Funct Mater, 28, 1707550(2018).

[215] J Wang, Y Mi, X Gao. Giant nonlinear optical response in 2D perovskite heterostructures. Adv Opt Mater, 7, 1900398(2019).

[216] L Wang, W Li, M Li. Ultrastable amine, sulfo cofunctionalized graphene quantum dots with high two-photon fluorescence for cellular imaging. ACS Sustainable Chem Eng, 6, 4711-4716(2018).

[217] X Zhu, H Xu, Y Liu. Two-photon up-conversion photoluminescence realized through spatially extended gap states in quasi-2D perovskite films. Adv Mater, 31, 1901240(2019).

[218] F O Saouma, C C Stoumpos, M G Kanatzidis. Multiphoton absorption order of CsPbBr₃ as determined by wavelength-dependent nonlinear optical spectroscopy. J Phys Chem Lett, 8, 4912-4917(2017).

[219] D Sharma, BP Malik, A Gaur. Two and four photon absorption and nonlinear refraction in undoped, chromium doped and copper doped ZnS quantum dots. J Phys Chem Solids, 87, 163-170(2015).

[220] D H Friese, R Bast, K Ruud. Five-photon absorption and selective enhancement of multiphoton absorption processes. ACS Photonics, 2, 572-577(2015).

[221] J Xiang, X Cai, X Lou. Biocompatible green and red fluorescent organic dots with remarkably large two-photon action cross sections for targeted cellular imaging and real-time intravital blood vascular visualization. ACS Appl Mater Interfaces, 7, 14965-14974(2015).

[222] R Feng, Y Sun, M Tian. A membrane-permeable dye for living cells with large two-photon excited fluorescence action cross-sections for bioimaging. J Mater Chem B, 3, 8644-8649(2015).

[223] N G Horton, K Wang, D Kobat. In vivo three-photon microscopy of subcortical structures within an intact mouse brain. Nat Photonics, 7, 205-209(2013).

[224] A Mushtaq, D Kushavah, S Ghosh. Nonlinear optical properties of benzylamine lead(II) bromide perovskite microdisks in femtosecond regime. Appl Phys Lett, 114, 051902(2019).

[225] A Manzi, Y Tong, J Feucht. Resonantly enhanced multiple exciton generation through below-band-gap multi-photon absorption in perovskite nanocrystals. Nat Commun, 9, 1518(2018).

[226] S Lu, F Zhou, Q Zhang. Layered hybrid perovskites for highly efficient three-photon absorbers: theory and experimental observation. Adv Sci, 6, 1801626(2019).

[227] W Chen, S Bhaumik, S A Veldhuis. Giant five-photon absorption from multidimensional core-shell halide perovskite colloidal nanocrystals. Nat Commun, 8, 15198(2017).

[228] S Bhaumik, S A Veldhuis, Y F Ng. Highly stable, luminescent core-shell type methylammonium-octylammonium lead bromide layered perovskite nanoparticles. Chem Commun, 52, 7118-7121(2016).

[229] B H Zhu, H C Zhang, J Y Zhang. Surface-related two-photon absorption and refraction of CdSe quantum dots. Appl Phys Lett, 99, 021908(2011).

[230] B H Zhu, H C Zhang, Z Y Zhang. Effect of shell thickness on two-photon absorption and refraction of colloidal CdSe/CdS core/shell nanocrystals. Appl Phys Lett, 99, 231903(2011).

[231] Q Zheng, H Zhu, S C Chen. Frequency-upconverted stimulated emission by simultaneous five-photon absorption. Nat Photonics, 7, 234-239(2013).

[232] H Chen, F Wang, M Liu. Near-infrared broadband polymer-dot modulator with high optical nonlinearity for ultrafast pulsed lasers. Laser Photonics Rev, 13, 1800326(2019).

[233] P Li, Y Chen, T Yang. Two-dimensional CH₃NH₃PbI₃ perovskite nanosheets for ultrafast pulsed fiber lasers. ACS Appl Mater Interfaces, 9, 12759-12765(2017).

[234] S Hong, F Lédée, J Park. Mode-locking of all-fiber lasers operating at both anomalous and normal dispersion regimes in the C-and L-bands using thin film of 2D perovskite crystallites. Laser Photonics Rev, 12, 1800118(2018).

[235] H Zhang, Q Liao, Y Wu. Two-dimensional Ruddlesden–Popper perovskites microring laser array. Adv Mater, 30, 1706186(2018).

[236] Z Gu, K Wang, W Sun. Two-photon pumped CH₃NH₃PbBr₃ perovskite microwire lasers. Adv Opt Mater, 4, 472-479(2016).

[237] Q Wei, B Du, B Wu. Two-photon optical properties in individual organic-inorganic perovskite microplates. Adv Opt Mater, 5, 1700809(2017).

[238] Y Zhang, C-K Lim, Z Dai. Photonics and optoelectronics using nano-structured hybrid perovskite media and their optical cavities. Phys Rep, 795, 1-51(2019).

[239] H Yu, Y Peng, Y Yang. Plasmon-enhanced light–matter interactions and applications. npj Comput Mater, 5, 45(2019).

[240] Q Shang, S Zhang, Z Liu. Surface plasmon enhanced strong exciton–photon coupling in hybrid inorganic–organic perovskite nanowires. Nano Lett, 18, 3335-3343(2018).

[241] M Kauranen, A V Zayats. Nonlinear plasmonics. Nat Photonics, 6, 737-748(2012).

[242] Z Xie, Y Duo, Z Lin. The rise of 2D photothermal materials beyond graphene for clean water production. Adv Sci, 7, 1902236(2020).

[243] Z Xie, D Wang, T Fan. Black phosphorus analogue tin sulfide nanosheets: synthesis and application as near-infrared photothermal agents and drug delivery platforms for cancer therapy. J Mater Chem B, 6, 4747-4755(2018).

[244] J Chen, T Fan, Z Xie. Advances in nanomaterials for photodynamic therapy applications: Status and challenges. Biomaterials, 237, 119827(2020).