Enhanced Photoresponse in GeSe‐Based Phototransistors by Ferroelectric Gating

Abstract

GeSe, a black phosphorus analogue, has great potential in the applications of optoelectronic devices due to its distinct optical properties and air stability. Developing techniques that can boost the photoresponsivity of GeSe‐based photodetectors is essential to promoting their practical applications. Herein, ferroelectric PbZrxTi1−xO3 (PZT) gating is introduced as an effective method to enhance the performance of GeSe‐based transistors. Comparative study on the performance of conventional Si/SiO2‐ and PZT‐gated GeSe phototransistors demonstrates a 3.1 times increase in photoresponsivity under zero gate voltage by ferroelectric gating. Furthermore, the PZT‐gated photodetector shows a rise time of 52 ms and a maximal external quantum efficiency (EQE) of 45% across the visible and near‐infrared range. These results indicate that ferroelectric gating is a promising methodology to enhance the performance of GeSe‐based photodetectors. This work paves a new pathway toward developing high‐performance photodetectors.