Hetero-integrated MoS 2 /CsPbBr 3 photodetector with enhanced performance via combinational modulation of grain boundary passivation and interfacial carrier separation

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.