Tailorable Polarity Switching and Optoelectronic Transition in a Gate-Source Integrated 2D Ferroelectric Phototransistor

Abstract

2D ferroelectric phototransistors are innovative devices capable of regulating the optoelectronic characteristics of channel materials through ferroelectric polarization, demonstrating immense potential in photodetection, optical storage, and optical communication. Herein, we present a novel 2D ferroelectric phototransistor structure-Au/WSe₂/CuCrP₂S₆/graphene-featuring an integrated gate-source electrode. By applying only the channel voltage, the major carrier type can be switched, and the optoelectronic performance is significantly enriched. Specifically, the structure enables positive/negative photoconduction switching at a low channel voltage of only 0.75 V, around which an optoelectronic transition occurs because of the ion migration. The optoelectronic transition manifests as a variation up to three orders of magnitude in the photocurrent decay time driven by the capture and release of photogenerated holes by Cu-ion vacancies, as well as positive and negative photoconduction switching triggered by different laser pulse intervals. This novel architecture offers an integrated platform that harnesses the distinctive characteristics of 2D ferroelectrics to dynamically and precisely tune the optoelectronic properties of 2D semiconductors.

Keywords: 2D ferroelectrics; 2D phototransitors; ion migration; negative photoconduction; optoelectronic transition.