Hybrid metal-halide perovskite-MoS₂ phototransistor

Two-dimensional (2D) molybdenum disulfide (MoS2) has attracted much attention as a promising next-generation optoelectronic device. In particular, multilayer MoS₂ has superior optical properties compared to mono- or few-layer MoS₂ because of its higher density of states and wider spectral response. However, as the number of layers increases, multilayer MoS₂ becomes indirect, resulting in poor light absorption and low photoresponsivity. Here, we report the enhanced photocurrent response of a multilayer MoS₂ thin-film transistor by stacking an organometal halide perovskite (CH₃NH₃PbI₃) layer on top of the multilyaer MoS₂. With the perovskite overlayer, the photocurrent increased by two orders of magnitude, and thus our proposed hybrid phototransistor exhibited significantly enhanced photoresponsivity of ∼1.1 A/W as well as detectivity of ∼9 × 10¹⁰ Jones compared to the MoS₂ phototransistor without the perovskite layer. We also observe that the electrical properties change because of the effect of the overlayer. Our result indicates that multilayer MoS₂ with a CH₃NH₃PbI₃ overlayer can be a promising structure for high-performance MoS₂-based photodetector applications.