Black-Arsenic/Germanium-on-Insulator Heterostructure Field Effect Transistor for Ultrafast Polarization Sensitive Short-Wave Infrared Photodetection

Purely monolithic or hybrid-monolithic integration of CMOS compatible platforms with IR active optical components can be a rewarding advancement towards scalable group IV MIR photonics. Here, a polarization-sensitive SWIR phototransistor based on black arsenic (b-As) and germanium (Ge) heterojunction is discussed. The device responds to a broad range of light spectrum (0.6 - 4 mu m). In the SWIR infrared band, the device has a high responsivity (402 A/W at 3 mu m), high detectivity (3.78 x 10(11) Jones), low noise equivalent power (4.4 x 10-15 WHz(1/2)), and a fast response (14.6 mu sec). Due to the anisotropy observed in b-As, the device also demonstrated highly polarization sensitive photocurrent. The present study opens up new avenues for 2D materials-based polarization sensitive CMOS compatible optical platforms.

Automated summary

This study discusses a polarization-sensitive SWIR phototransistor based on black arsenic and germanium heterojunction, which exhibits high responsivity, high detectivity, fast response, and highly polarization sensitive photocurrent.