Germanium-Tin heterojunction phototransistor: Towards high-efficiency low-power photodetection in short-wave infrared range

Abstract

We report the world's first demonstration of Germanium-Tin (Ge1-xSnx) heterojunction phototransistor (HPT) for high-efficient low-power light detection in short-wave infrared (SWIR) range. Large optical response enhancement of ~10 times over the conventional p-i-n Ge1-xSnx photodiode (PD) was achieved, with photodetection beyond 2003 nm. High responsivities of ~2.6 A/W at 1510 nm and ~0.19 A/W at 1877 nm were achieved at a low operating bias of 1.0 V.