[1] S De Wolf, J Holovsky, S J Moon et al. Organometallic halide perovskites: sharp optical absorption edge and its relation to photovoltaic performance. J Phys Chem Lett, 5, 1035(2014).

[2] G Xing, N Mathews, S Sun et al. Long-range balanced electron-and hole-transport lengths in organic-inorganic CH₃NH₃PbI₃. Science, 342, 344(2013).

[3] H Yoon, S M Kang, J K Lee et al. Hysteresis-free low-temperature-processed planar perovskite solar cells with 19.1% efficiency. Energy Environ Sci, 9, 2262(2016).

[4] G Xing, N Mathews, S S Lim et al. Low-temperature solution-processed wavelength-tunable perovskites for lasing. Nat Mater, 13, 476(2014).

[5] J H Heo, S H Im, J H Noh et al. Efficient inorganic–organic hybrid heterojunction solar cells containing perovskite compound and polymeric hole conductors. Nat Photonics, 7, 486(2013).

[6] D Bryant, P Greenwood, J Troughton et al. A transparent conductive adhesive laminate electrode for high-efficiency organic-inorganic lead halide perovskite solar cells. Adv Mater, 26, 7499(2014).

[7] Q Jiang, L Zhang, H Wang et al. Enhanced electron extraction using SnO₂ for high-efficiency planar-structure HC(NH₂)₂PbI₃-based perovskite solar cells. Nat Energy, 2, 1(2016).

[8] N Aeineh, E M Barea, A Behjat et al. Inorganic surface engineering to enhance perovskite solar cell efficiency. ACS Appl Mater Interfaces, 9, 13181(2017).

[9] V Gonzalez-Pedro, E J Juarez-Perez, W S Arsyad et al. General working principles of CH₃NH₃PbX₃ perovskite solar cells. Nano Lett, 14, 888(2014).

[10] K Yang, J Fu, L Hu et al. Impact of ZnO photoluminescence on organic photovoltaic performance. ACS Appl Mater Interfaces, 10, 39962(2018).

[11]

[12] J Xie, X Yu, X Sun et al. Improved performance and air stability of planar perovskite solar cells via interfacial engineering using a fullerene amine interlayer. Nano Energy, 28, 330(2016).

[13] H Kim, K G Lim, T W Lee. Planar heterojunction organometal halide perovskite solar cells: roles of interfacial layers. Energy Environ Sci, 9, 12(2016).

[14] Z K Wang, X Gong, M Li et al. Induced crystallization of perovskites by a perylene underlayer for high-performance solar cells. ACS Nano, 10, 5479(2016).

[15] X Liu, B Li, N Zhang et al. Multifunctional RbCl dopants for efficient inverted planar perovskite solar cell with ultra-high fill factor, negligible hysteresis and improved stability. Nano Energy, 53, 567(2018).

[16] L Hu, M Li, K Yang et al. PEDOT:PSS monolayers to enhance the hole extraction and stability of perovskite solar cells. J Mater Chem A, 6, 16583(2018).

[17] M Qian, M Li, X B Shi et al. Planar perovskite solar cells with 15.75% power conversion efficiency by cathode and anode interfacial modification. J Mater Chem A, 3, 13533(2015).

[18] L Zhao, D Luo, J Wu et al. High-performance inverted planar heterojunction perovskite solar cells based on lead acetate precursor with efficiency exceeding 18%. Adv Funct Mater, 26, 3508(2016).

[19] E J Juarez-Perez, M Wuβler, F Fabregat-Santiago et al. Role of the selective contacts in the performance of lead halide perovskite solar cells. J Phys Chem Lett, 5, 680(2014).

[20] V W Bergmann, S A Weber, F J Ramos et al. Real-space observation of unbalanced charge distribution inside a perovskite-sensitized solar cell. Nat Commun, 5, 5001(2014).

[21] A Abrusci, S D Stranks, P Docampo et al. High-performance perovskite-polymer hybrid solar cells via electronic coupling with fullerene monolayers. Nano Lett, 13, 3124(2013).

[22] W Tress, N Marinova, T Moehl et al. Understanding the rate-dependent J–V hysteresis, slow time component, and aging in CH₃NH₃PbI₃ perovskite solar cells: the role of a compensated electric field. Energy Environ Sci, 8, 995(2015).

[23] X Crispin, F L Jakobsson, A Crispin et al. The origin of the high conductivity of poly (3, 4-ethylenedioxythiophene)− poly (styrenesulfonate)(PEDOT−PSS) plastic electrodes. Chem Mater, 18, 4354(2006).

[24] X Zheng, Y Bai, S Xiao et al. Strategies for improving efficiency and stability of perovskite solar cells. MRS Adv, 2, 3051(2017).

[25] X Huang, K Wang, C Yi et al. Efficient perovskite hybrid solar cells by highly electrical conductive PEDOT:PSS hole transport layer. Adv Energy Mater, 6, 1501773(2016).

[26] I Anusca, S Balčiūnas, P Gemeiner et al. Dielectric response: answer to many questions in the methylammonium lead halide solar cell absorbers. Adv Energy Mater, 7, 1700600(2017).

[27] Y Jiang, C Li, H Liu et al. Poly (3, 4-ethylenedioxythiophene): poly (styrenesulfonate)(PEDOT:PSS) –molybdenum oxide composite films as hole conductors for efficient planar perovskite solar cells. J Mater Chem A, 4, 9958(2016).

[28] Z Wang, Y Lou, S Naka et al. Direct comparison of solution- and vacuum-processed small molecular organic light-emitting devices with a mixed single layer. ACS Appl Mater Interfaces, 3, 2496(2011).

[29] P Schulz, J O Tiepelt, J A Christians et al. High-work-function molybdenum oxide hole extraction contacts in hybrid organic–inorganic perovskite solar cells. ACS Appl Mater Interfaces, 8, 31491(2016).

[30] H S Kim, J B Cook, H Lin et al. Oxygen vacancies enhance pseudocapacitive charge storage properties of MoO_3−x. Nat Mater, 16, 454(2017).

[31] M H Lee, L Chen, N Li et al. MoO₃-induced oxidation doping of PEDOT: PSS for high performance full-solution-processed inverted quantum-dot light emitting diodes. J Mater Chem C, 5, 10555(2017).

[32] W H Nguyen, C D Bailie, E L Unger et al. Enhancing the hole-conductivity of spiro-OMeTAD without oxygen or lithium salts by using spiro (TFSI)₂ in perovskite and dye-sensitized solar cells. J Am Chem Soc, 136, 10996(2014).

[33] N Wang, K Zhao, T Ding et al. Improving interfacial charge recombination in planar heterojunction perovskite photovoltaics with small molecule as electron transport layer. Adv Energy Mater, 7, 1700522(2017).

[34] Z Li, J Tinkham, P Schulz et al. Acid additives enhancing the conductivity of Spiro-OMeTAD toward high-efficiency and hysteresis-less planar perovskite solar cells. Adv Energy Mater, 7, 1601451(2017).

[35] Y Shao, Y Yuan, J Huang. Correlation of energy disorder and open-circuit voltage in hybrid perovskite solar cells. Nat Energy, 1, 1(2016).

[36] A Dualeh, T Moehl, N Tétreault et al. Impedance spectroscopic analysis of lead iodide perovskite-sensitized solid-state solar cells. ACS Nano, 8, 362(2014).

[37] A Pockett, G E Eperon, T Peltola et al. Characterization of planar lead halide perovskite solar cells by impedance spectroscopy, open-circuit photovoltage decay, and intensity-modulated photovoltage/photocurrent spectroscopy. J Phys Chem C, 119, 3456(2015).

[38] A M Humada, M Hojabri, S Mekhilef et al. Solar cell parameters extraction based on single and double-diode models: A review. Renew Sustain Energy Rev, 56, 494(2016).

[39] F Tan, S Qu, Q Jiang et al. Interpenetrated inorganic hybrids for efficiency enhancement of PbS quantum dot solar cells. Adv Energy Mater, 4, 1400512(2014).

[40] Z Liu, S Niu, N Wang. Light illumination intensity dependence of photovoltaic parameter in polymer solar cells with ammonium heptamolybdate as hole extraction layer. J Colloid Interface Sci, 509, 171(2018).

[41] A Baumann, K Tvingstedt, M C Heiber et al. Persistent photovoltage in methylammonium lead iodide perovskite solar cells. Appl Mater, 2, 081501(2014).

[42] F Tan, H Tan, M I Saidaminov et al. In situ back-contact passivation improves photovoltage and fill factor in perovskite solar cells. Adv Mater, 31, 1807435(2019).

[43] Y Shao, Z Xiao, C Bi et al. Origin and elimination of photocurrent hysteresis by fullerene passivation in CH₃NH₃PbI₃ planar heterojunction solar cells. Nat Commun, 5, 5784(2014).

[44] L Hu, K Sun, M Wang et al. Inverted planar perovskite solar cells with a high fill factor and negligible hysteresis by the dual effect of NaCl-doped PEDOT: PSS. ACS Appl Mater Interfaces, 9, 43902(2017).

[45] M Kuik, L J Koster, G A Wetzelaer et al. Trap-assisted recombination in disordered organic semiconductors. Phys Rev Lett, 107, 256805(2011).

[46] D Sapori, M Kepenekian, L Pedesseau et al. Quantum confinement and dielectric profiles of colloidal nanoplatelets of halide inorganic and hybrid organic–inorganic perovskites. Nanoscale, 8, 6369(2016).

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