Hetero-integrated MoS2/CsPbBr3 photodetector with enhanced performance via combinational modulation of grain boundary passivation and interfacial carrier separation
Yan Zhang, Chengyun Wu, Xinyang Zhou, Junchun Li, Xuyong Tao, Boyan Liu, Junwei Chen, Yajing Chang, Guoqing Tong, Yang Jiang
Abstract
The distinguished electronic and optical properties of all-inorganic lead halide perovskites (CsPbX 3 , X = Cl, Br, I) qualify them as ideal candidates for active layer in optoelectronic devices , especially showing more competitive development prospects in photodetection with high performance. However, superior device performance and good long-term stability is still a challenge for perovskite-based photodetectors applying in practical situation. Herein, we demonstrate a novel hetero-integrated MoS 2 /CsPbBr 3 photodetector displaying efficient device performance, where the MoS 2 nanocrystals pre-synthesized by hydrothermal route were spin-coated on the surface of CsPbBr 3 films with controllable dispersion, providing effective interfacial photo-carriers separation at MoS 2 /CsPbBr 3 van der Waals heterojunction (vdWH) and significant defect passivation for perovskite grain boundaries (GBs) simultaneously, thus boosting optoelectronic performance of our device within ultraviolet (UV)-visible wavelength range, including a higher photoresponsivity (4.79 A/W), enhanced specific detectivity (8.81 × 10 12 Jones) and more durable stability than that of the pristine CsPbBr 3 photodetector. Furthermore, the fast response speed (0.17/0.22 ms) is obviously more outstanding than that of most CsPbBr 3 -based and congeneric hybrid photodetectors. These results, combined with our experimental design strategy of the device described herein, provide an efficient approach to achieve stable, high-performance photodetection using perovskite-based hybrid nanomaterial systems, thus opening up new possibilities for two-dimensional (2D) materials/perovskites hetero-integration based photovoltaic and optoelectronic applications in the future.