Highly sensitive visible to infrared MoTe₂ photodetectors enhanced by the photogating effect

Two-dimensional materials are promising candidates for electronic and optoelectronic applications. MoTe₂ has an appropriate bandgap for both visible and infrared light photodetection. Here we fabricate a high-performance photodetector based on few-layer MoTe₂. Raman spectral properties have been studied for different thicknesses of MoTe₂. The photodetector based on few-layer MoTe₂ exhibits broad spectral range photodetection (0.6-1.55 μm) and a stable and fast photoresponse. The detectivity is calculated to be 3.1 ×10⁹ cm Hz^1/2 W^-1 for 637 nm light and 1.3 ×10⁹ cm Hz^1/2W^-1 for 1060 nm light at a backgate voltage of 10 V. The mechanisms of photocurrent generation have been analyzed in detail, and it is considered that a photogating effect plays an important role in photodetection. The appreciable performance and detection over a broad spectral range make it a promising material for high-performance photodetectors.