Fully Depleted Self-Aligned Heterosandwiched Van Der Waals Photodetectors

Room-temperature-operating highly sensitive mid-wavelength infrared (MWIR) photodetectors are utilized in a large number of important applications, including night vision, communications, and optical radar. Many previous studies have demonstrated uncooled MWIR photodetectors using 2D narrow-bandgap semiconductors. To date, most of these works have utilized atomically thin flakes, simple van der Waals (vdW) heterostructures, or atomically thin p-n junctions as absorbers, which have difficulty in meeting the requirements for state-of-the-art MWIR photodetectors with a blackbody response. Here, a fully depleted self-aligned MoS2-BP-MoS2 vdW heterostructure sandwiched between two electrodes is reported. This new type of photodetector exhibits competitive performance, including a high blackbody peak photoresponsivity up to 0.77 A W-1 and low noise-equivalent power of 2.0 x 10(-14) W Hz(-1/2), in the MWIR region. A peak specific detectivity of 8.61 x 10(10) cm Hz(1/2) W-1 under blackbody radiation is achieved at room temperature in the MWIR region. Importantly, the effective detection range of the device is twice that of state-of-the-art MWIR photodetectors. Furthermore, the device presents an ultrafast response of approximate to 4 mu s both in the visible and short-wavelength infrared bands. These results provide an ideal platform for realizing broadband and highly sensitive room-temperature MWIR photodetectors.

Automated summary

In this study, a fully depleted self-aligned MoS2-BP-MoS2 vdW heterostructure photodetector with high sensitivity and broad wavelength range was reported, which is a new type of room-temperature operating MWIR photodetector.