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

Abstract

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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> ). In the SWIR infrared band, the device has a high responsivity (402 A/W at 3 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> ), high detectivity (3.78 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times 10^{{11}}$ </tex-math></inline-formula> Jones), low noise equivalent power (4.4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times10$ </tex-math></inline-formula> -15 WHz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sup> ), and a fast response (14.6 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> 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.

Topics & Concepts