MoS₂/Silicon-on-Insulator Heterojunction Field-Effect-Transistor for High-Performance Photodetection

Abstract

In this letter, we demonstrate a novel junction field-effect transistor by transferring MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> onto a silicon-on-insulator (SOI) substrate to control the thin Si channel. By combining high light absorption coefficient in MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> with high internal gain in thin Si channel, the device can be used for photodetection and can achieve high responsivity up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim {1.78}\times {10}^{4}$ </tex-math></inline-formula> A/W, high detectivity over <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${3}\times {10}^{13}$ </tex-math></inline-formula> Jones, and short response time down to 1.44 ms. Furthermore, unlike the conventional SOI photodetector, which is only sensitive to UV light, the response spectrum of our proposed device peaks in visible/near-infrared region, which is interesting for imaging and optical communication applications.