Fig. 1. The schematic diagrams: (a) 2D Materials with intercalation^[10]; (b) graphene/MoS₂/PMN-PT heterostructure^[11]; (c) MoS₂/P(VDF-TrFE)/SiO₂/Si heterostructure^[5]. 结构示意图　(a) 中间插层的二维材料^[10]; (b) 石墨烯/MoS₂/PMN-PT异质结^[11]; (c) MoS₂/P(VDF-TrFE)/SiO₂/Si异质结^[5]

Fig. 2. (a) The eight possible polarization directions for an unpoled PMN-PT single crystal: r1⁺, r2⁺, r3⁺, r4⁺, r1^–, r2^–, r3^–, r4^–[12]; (b) ε_xx – E curves for PMN-PT(001) single crystals^[13]; (c) photoluminescence spectra of the MoS₂ under various strains^[11]; (d) ε_xx – E curves for PMN-PT(011) single crystals^[15]. (a) PMN-PT未被极化时具有8个自发极化方向: r1⁺, r2⁺, r3⁺, r4⁺, r1^–, r2^–, r3^–, r4^–[12]; (b) PMN-PT(001)单晶的应变-电场曲线^[13]; (c) 不同应变状态下, MoS₂的光致发光谱^[11]; (d) 不同外加电场下, PMN-PT(011)单晶的应变-电场曲线^[15]

Fig. 3. (a) Polarization-Electric field (P-E) hysteresis loop of PMN-PT substrate, and schematic diagrams of interface charge effects in graphene/PMN-PT FeFET^[16]; (b) the I_ds–V_g curves of graphene on PMN-PT^[16]. (a) PMN-PT铁电单晶衬底的极化-电场(P-E)曲线, 及外加电场下石墨烯/PMN-PT铁电场效应晶体管的界面电荷效应示意图^[16]; (b) 石墨烯/PMN-PT铁电场效应晶体管的I_ds–V_g曲线^[16]

Fig. 4. (a) Schematic of the graphene/PZT/STO heterostructure^[20]; (b) AFM image of a multilayer graphene sheet on a 300 nm PZT film^[21]; (c) the channel resistivity of graphene/PZT FeFET as a function of the gate voltage with different memory operation^[21]. (a) 石墨烯/PZT/STO异质结的示意图^[20]; (b) 300 nm PZT上的多层石墨烯AFM图^[21]; (c) 不同栅压走向下, 石墨烯/PZT FeFET的电阻率ρ随栅压V_g的变化曲线^[21]

Fig. 5. (a) I_DS-V_G characteristics of the exfoliated-graphene/PZT FeFET^[23]; (b) I_DS-V_G characteristics of the CVD-graphene/PZT FeFET^[23]; (c) I_DS-V_G of the graphene/PZT FeFET under a drain voltage at 50 mV^[25]; (d) drain current as a function of gate voltage of graphene/PZT FeFET in air and vacuum, respectively^[25]. (a) 机械剥离-石墨烯/PZT FeFET的I_DS-V_G曲线^[23]; (b) CVD-石墨烯/PZT FeFET的I_DS-V_G曲线^[23]; (c) V_DS = 50 mV时, 石墨烯/PZT FeFET中的I_DS-V_G曲线^[25]; (d) 不同栅压下, 真空和空气中分别测得的I_DS-V_G曲线^[25]

Fig. 6. (a) Scheme of the electrical measurements of graphene/PZT FeFETs at different polarization state of PZT^[28]; (b) after application of the write (V_G = –6 V) or erase (V_G = +6 V) voltages, the ON and OFF drain–source currents at the read voltage (V_G = 0) and an auxiliary pulse (V_G = –1.25 V) were measured as a function of time^[28]; (c) schematic device structure of the graphene/PZT FeFET^[29]; (d) I_d-V_G characteristics measured in vacuum 250 s and 24 h after switching for both the UP and DOWN polarization states^[29]. (a) PZT处于不同极化状态时, 石墨烯/PZT的I_DS-V_G曲线^[28]; (b) 在施加V_G = –6 V和V_G = 6 V的擦写电压后, 石墨烯/PZT FET分别处于“ON”态和“OFF”时的漏极电流随时间的变化曲线^[28]; (c) 石墨烯/PZT FET结构示意图^[29]; (d) 在PZT薄膜翻转为向上和向下的极化状态后, 分别在真空中放置250 s和24 h后测得的I_d-V_G曲线^[29]

Fig. 7. (a) Schematic of the electro-mechanical device used to apply in-plane biaxial strain to the graphene^[33]; (b) D, G, 2D and 2D’ peaks plotted as a function of the biaxial strain ε_||^[33]; (c) schematic of graphene/PMNPT heterostructure^[34]; (d) the PMN-PT (002) peaks of XRD 2θ scanning patterns with different bias voltage^[34]; (e) 2D peaks of graphene under different bias voltage^[34]. (a)对石墨烯/PMN-PT施加电场的示意图^[33]; (b) 石墨烯的D, G, 2D和2D’峰位随面内应变的变化曲线^[33]; (c) 石墨烯/PMN-PT异质结构示意图^[34]; (d) 不同外场下PMN-PT(002)峰的XRD图^[34]; (e) 不同外场下石墨烯的2D拉曼峰图^[34]

Fig. 8. (a) The I_ds-V_g curves of graphene on PMN-PT^[16]; (b) charge carrier density of graphene on PMN-PT as a function of the gate voltage^[35]; (c) schematic diagrams of the graphene/h-BN/PMN-PT FET^[36]; (d) I_ds-V_g curves of graphene at different gate-voltage sweep ranges^[36]. (a) 石墨烯/PMN-PT FeFET的I_ds-V_g曲线^[16]; (b) 石墨烯的载流子浓度随栅压的变化曲线^[35]; (c) 石墨烯/h-BN/PMN-PT FET示意图^[36]; (d) 不同栅压范围下的I_ds-V_g曲线^[36]

Fig. 9. (a) The electric displacement field D of the graphene/P(VDF-TrFE) FeFET and D’ of P(VDF-TrFE) thin film as a function of the applied electric field^[42]; (b) the resistance endurance property of the graphene/P(VDF-TrFE) FeFET^[43]; (c) optical image of the flexible transparent graphene/P(VDF-TrFE) FeFET device^[44]; (d) I_sd and I_tg vs V_tg curves of the graphene/P(VDF-TrFE) FeFET^[46]. (a) 石墨烯/P(VDF-TrFE)的电位移D和P(VDF-TrFE)的电位移D’随外加电场的变化曲线^[42]; (b) 石墨烯/P(VDF-TrFE)的电阻持久性能^[43]; (c) 石墨烯/P(VDF-TrFE)柔性透明导电器件光学照片^[44]; (d) 石墨烯/P(VDF-TrFE)的I_sd和I_tg随栅极电压的变化曲线^[46]

Fig. 10. (a) Photograph of the graphene/P(VDF-TrFE)/graphene based acoustic device and the measurement circuit^[47]; (b) schematic depiction showing graphene/P(VDF-TrFE)/graphene-based device can work as an actuator as well as a nanogenerator^[47]; (c) schematics and photograph of graphene/PVDF/graphene based generator and loudspeaker^[48]; (d) photographic image of the pressure measurement setup showing the pressurized gas inlet, the sensor mounting, and the data acquisition system^[49]; (e) short-circuit current of the P(VDF-TrFE)/PMN-PT/GO film when attached on the human hand^[51]; (f) a schematic of data writing and reading on GO/P(VDF-TrFE) Multilayer film by a PFM tip^[52]. (a) 基于石墨烯/P(VDF-TrFE)/石墨烯复合结构的声压器件和测试回路照片^[47]; (b) 基于石墨烯/P(VDF-TrFE)/石墨烯复合结构的声压驱动器和纳米发电机的示意图^[47]; (c) 基于P(VDF-TrFE)/石墨烯复合结构的发电机和话筒的示意图和照片^[48]; (d) 基于P(VDF-TrFE)/石墨烯复合结构的压力测试装置^[49]; (e) 当被粘贴在手上时P(VDF-TrFE)/PMN-PT/GO薄膜的短路电流^[51]; (f) 用PFM探针在GO/P(VDF-TrFE)上写入和读取数据的示意图^[52]

Fig. 11. (a) Schematic diagram of the PZT back gated MoS₂ FeFET^[57]; (b) the transfer curves of MoS₂/PZT FET. Memory window variation with increasing V_G sweep range as shown in the inset^[57]; (c) the transfer characteristics of MoS₂ transistors fabricated on PZT films with different surface qualities^[59]; (d) the I_ds-V_gs curves of MoS₂/PZT FETs under different temperatures rising from 300 to 380 K and V_gmax at 8 V^[61]. (a) 以PZT为背栅的MoS₂ FET示意图^[57]; (b) MoS₂/PZT FET的转移特性曲线, 插图为存储窗口随最大扫描电压的变化曲线^[57]; (c) 不同表面粗糙度的MoS₂/PZT FET转移特性曲线^[59]; (d) MoS₂/PZT FET在不同温度下的转移特性曲线^[61]

Fig. 12. (a) I_DS-V_G characteristics for the same MoS₂/PZT FeFET measured while V_G was applied and 5 min after the corresponding gate voltages were applied, respectively^[63]; (b) effect of light illumination on the retention properties of the FeFET^[63]; (c) PFM phase images of a MoS₂-PZT FeFET with one and three conductive paths gated by the domains with the downward polarization^[64]; (d) I_DS-V_DS curves for different numbers of conductive paths^[64]. (a) 同一个MoS₂/PZT FeFET在加栅压的同时和加栅压静置5 min后的I_DS-V_G曲线^[63]; (b) 光照对FeFET器件开关持续能力的影响^[63]; (c) 以向下的铁电畴为栅极的MoS₂-PZT FeFET的PFM相位图^[64]; (d) 不同数量导电通道的I_DS-V_DS曲线^[64]

Fig. 13. (a) Device schematic of the 2D TMD/PZT heterostructure^[65]; (b) effect of different polarization state for PZT on the PL spectra of WSe₂^[65]; (c, d) the maps of integrated PL intensity under down- and up-polarized states, respectively^[64]; (e) PL peak intensity map obtained from the WS₂ monolayer over a 30 × 30 μm² area under different polarized states^[66]; (f) raw PL spectra (solid black line) and fits (dashed green line) using two Lorentzians centered at 2.01 eV (red line) and 1.99 eV (blue line)^[66]. (a) 2D/PZT FeFET的结构示意图^[65]; (b) PZT不同极化态对WSe₂ PL光谱的影响^[65]; (c, d) PZT不同极化态下, WSe₂的PL发光分布图^[65]; (e) PZT不同极化态下, WS₂的PL发光分布图^[66]; (f) PZT不同极化态下, WS₂的PL光谱及拟合曲线^[66]

Fig. 14. (a) Schematic diagram of MoS₂/PMN-PT composite^[11]; (b) in-situ photoluminescence (PL) spectra of MoS₂/PMN-PT composite under different strain states^[11]; (c) calculated band structure of trilayer MoS₂ as a function of the strain^[11]; (d) schematic of MoS₂/PMN-PT FET^[67]; (e) I_ds – V_ds curves of MoS₂/PMN-PT FET under different light illumination with gate voltage V_G = 0 V^[67]; (f) the time-resolved photocurrent in response to IR on/off at an irradiance of 6 mW/mm^2[67]. (a) MoS₂/PMN-PT的结构示意图^[11]; (b) 不同应力作用下MoS₂的光致发光光谱^[11]; (c) 不同应力作用下MoS₂的能带示意图^[11]; (d) PMN-PT/MoS₂ FET的结构示意图^[67]; (e) 无栅极电压时, PMN-PT/MoS₂ FET在不同强度光照下的伏安特性曲线^[67]; (f) PMN-PT/MoS₂ FET的沟道电流随红外光照开/关的响应曲线^[67]

Fig. 15. (a) Schematic showing the three-phase coupling among magnetism, semiconductor, and piezoelectricity^[68]; (b) 3D schematic illustration of an MoS₂-based MIPG-FET^[68]; (c) transient response of the MIPG-FET at H = 33 mT at Pr⁺ state^[68]; (d) transient response of the MIPG-FET at H = 42 mT at Pr^– state^[68]. (a) 磁性、半导体性、压电性相互耦合示意图^[68]; (b) MoS₂基MIPG-FET的3D示意图^[68]; (c) PMN-PT正向极化态下, MoS₂基MIPG-FET对H = 33 mT的瞬态响应^[68]; (d) PMN-PT负向极化态下, MoS₂基MIPG-FET对H = 42 mT的瞬态响应^[68]

Fig. 16. (a) Schematic 3D top-view of the MoS₂-FET^[69]; (b) Detailed plots of SS and g_m as a function of L_ch^[73]; (c) 3D schematic diagram of the P(VDF-TrFE) top gated MoSe₂ FeFET^[74]; (d) retention performance of this device at the write and erase states^[74]. (a) MoS₂基FET的3D模型图^[69]; (b) 亚阈值摆幅和电导随沟道长度的变化曲线^[73]; (c) 以P(VDF-TrFE)为顶栅的MoSe₂基FeFET的3D模型图^[74]; (b) MoSe₂基FeFET在写入和擦除状态下的持久性能^[74]

Fig. 17. (a) 3D schematic diagram of the P(VDF-TrFE) top gated MoS₂ phtodetector with light beam^[75]; (b) photoswitching behavior of ferroelectric polarization gating triple-layer MoS₂ photodetector at three states^[75]; (c) the schematic diagram of back-gate MoTe₂ FET in which HfO₂ of 30 nm is deposited on MoTe₂ before coating P(VDF-TrFE) polymer^[77]; (d) drain-source characteristics of the In₂Se₃ phtodetector in the dark and under different illuminating light wavelength (520−1550 nm)^[76]. (a) P(VDF-TrFE)顶栅MoS₂光电FET在光照下的3D模型图^[75]; (b) P(VDF-TrFE)处于不同极化状态时, MoS₂光电FET的光开关行为^[75]; (c) 以P(VDF-TrFE)顶栅并中插HfO₂薄膜的MoTe₂光电FET示意图^[77]; (d) 在黑暗及不同光照强度(520−1550 nm)下, In₂Se₃光电FET的伏安特性曲线^[76]

Fig. 18. (a) The optical micrograph shows preferential growth of single-layer MoS₂ on LiNbO₃ domains^[80]; PL mapping of exfoliated monolayer (b) MoSe₂ and (c) WSe₂ on a single polarized domain. The gold dashed line indicates one single dipole^[81]; (d) a sketch of the experiment geometry in MoS₂/BaTiO₃/SrRuO₃ junctions^[85]; (e)−(f) PFM phase images of MoS₂/BaTiO₃/SrRuO₃ junctions acquired in the dark before and after UV illumination^[85]. (a) 单层薄膜在LiNbO₃铁电畴上择优生长的光学照片和在单极化域上的双层^[80]; (b) MoSe₂和(c) WSe₂的光致发光分布图^[81]; (d) 在MoS₂/BaTiO₃/SrRuO₃上的测试示意图^[85]; (e−f) MoS₂/BaTiO₃/SrRuO₃在紫外光照前后的PFM相图^[85]

Fig. 19. (a) The resistance R as a function of the temperature T for the CBS films at P_r⁺ state and P_r^– state, respectively^[92]; (b) schematic band diagrams of the Fermi level shift induced by polarization Switching^[92]; (c) schematic of dual-gated P(VDF-TrFE)/BP/MoS₂/SiO₂/Si FeFET^[94]; (d) schematic illustration of the photoelectric memory in FeFET with BP/PZT heterostructure fabricated on LNO/SiO₂/Si substrate^[95]; (e) dynamic cycles of the “electrical writing-optical reading” process of the BP/PZT/LNO/SiO₂/Si memory^[95](a) PMN-PT衬底分别处于P_r⁺, P_r^–态时, CBS薄膜的电阻R随温度T的变化曲线, 插图: CBS薄膜的载流子浓度随温度T的变化曲线^[92]; (b) PMN-PT衬底极化翻转引起的CBS薄膜费米能级移动的示意图^[92]; (c) P(VDF-TrFE)/BP/MoS₂/SiO₂/Si结构FeFET示意图^[94]; (d) 在BP/PZT/LNO/SiO₂/Si结构的FeFET中光电存储原理图^[95]; (e) 在BP/PZT/LNO/SiO₂/Si结构存储器中的“电写光读”动态循环曲线^[95]