Design and Analysis of p-i-n-Type MoS2/Ge Heterojunction Photodetector

Wide spectrum, highly sensitive photodetectors are of great importance for many optoelectronic applications. MoS(2 )is an extremely desirable two-dimensional (2-D) material for fabricating high-performance photodetectors by forming van der Waals heterojunctions with conventional semiconductors. To address this issue, a p-i-n-type MoS2/Ge heterojunction photodetector based on multilayer MoS2 is proposed in this article, and the photodetector's features are explored using simulations. The results show that the dark current of the detector is 1.61 x 10(-17 )A, while the photocurrent is 7.71 x 10(-7) A at 0 V bias, showing a strong photovoltaic effect. Furthermore, the average responsivity of the photodetector is about 6 A/W in the spectral range of 200-1400 nm; the average noise equivalent power (NEP) and specific detectivity are in the range of 10(-18) W/Hz(1/2 )and 10(14 )Jones at zero bias voltage, respectively. The 3 dB bandwidth of the device at 1310 nm illumination is up to 19.2 GHz. These excellent performance metrics essentially indicate a massive potential of MoS2/Ge heterostructures for optoelectronic applications.