Enhanced Photoresponse in Hybrid Perovskite Thin Film via Interfacing with MoS₂

In this work, we demonstrated up to two orders of magnitude enhancement in the photoresponse of hybrid perovskite CH₃NH₃PbI₃ (MAPbI₃) polycrystalline thin film via interfacing with few-layer MoS₂. We mechanically exfoliated few-layer MoS₂ flake and transferred it onto the SiO₂/Si substrate. The sample was fabricated into 2 point device, on top of which we spincoated uniformly 500 nm MAPbI₃ film. Between the two parallel Au electrodes, half of the area contains the MoS₂-MAPbI₃ hybrid structure, while the other half contains only single layer MAPbI₃. We performed high-resolution photocurrent mapping within those two channels, and observed that the MoS₂-MAPbI₃ region had up to two orders of magnitude higher photocurrent than single layer MAPbI₃. The enhancement is consistent with a much higher absorption from the MoS₂-MAPbI₃ hybrid structure due to the band alignment between these two materials, which facilitated photo-carrier separation. The MoS₂-MAPbI₃ hybrid device showed faster transient photoresponse of 200-300 μs, which makes it promising for constructing high performance photo-detectors.