Hybrid Field-Effect Transistors and Photodetectors Based on Organic Semiconductor and CsPbI3 Perovskite Nanorods Bilayer Structure

Recently, organometal halide perovskites have attracted a significant interest in the field of optoelectronics owing to their desirable electronic and optoelectronic properties, such as strong and broad light absorption, weakly bound excitons, long-range-balanced electron/hole transport lengths, and low-cost fabrication [ 1 , 2 ]. These characteristics make them widely use in solar cells [ 3 , 4 ], light-emitting diodes (LEDs) [ 5 , 6 ], lasing [ 7 ], and photodetectors [ 8 , 9 , 10 ]. However, these perovskite materials usually have a low long-term stability owing to the environmental degradation of organic cations within the materials from moisture and heat [ 11 , 12 ]. In contrast, all-inorganic CsPbX 3 (X = I, Br, Cl) perovskites exhibit decent stabilities; among them, the CsPbI 3 perovskite exhibited unique properties with a suitable bandgap, high quantum efficiency, and long radiative lifetime [ 13 , 14 ]. However, this material has two phases: cubic phase and orthorhombic phase. The black cubic phase is stable above 300 °C; it quickly undergoes phase transformation into the wider-bandgap (3.01 eV) orthorhombic phase upon cooling to room temperature. This phase transformation largely limited its applications. In order to overcome this problem, low-dimensional CsPbI 3 perovskites, including quantum dots, nanowires, nanorods, and nanoplates, have been prepared. Owing to both surface and nanoeffects, as the size of the perovskite material is reduced to the nanoscale, the phase stability can significantly differ from that in the bulk counterpart [ 15 , 16 , 17 , 18 ].