High-Performance and Linearly Polarized MoTe₂/ReS₂ Heterojunction Phototransistors

Abstract

Two-dimensional transition metal dichalcogenides have garnered significant research interest due to their excellent photoelectric properties. However, the low photocurrent to dark current ratio has restricted their application in visible light imaging. In this study, we fabricated a high-performance phototransistor using a MoTe ₂ and ReS ₂ flakes heterojunction to enhance the application potential of phototransistors. The resulting device exhibited a high responsivity of 65.4 A/W, a large current on/off ratio of 43.7, a fast response speed of 480/ $490~\mu $ s, an external quantum efficiency of up to ${1}.{38}\times {10} ^{{4}}$ %, specific detectivity reaching up to ${6}.{25}\times {10} ^{{12}}$ Jones, a subthreshold swing as low as 125 mV/dec, and carrier mobility up to 319 cm ² /V $\cdot $ s. Notably, the photodetector based on this heterojunction demonstrates visible light imaging functionality. Our work paves the way for developing high-performance phototransistors.