【Domestic Papers】 South China Normal University——Gate-tunable positive and negative photoresponses based on a mixed-dimensional Ga₂O₃/WSe₂ junction field-effect transistor for logic operation

      Researchers from the South China Normal University have published a dissertation titled "Gate-tunable positive and negative photoresponses based on a mixed-dimensional Ga₂O₃/WSe₂ junction field-effect transistor for logic operation" in Photonics Research.

Abstract

      Realization of positive and negative optical responses in a single device promises construction of multifunctional optoelectronic devices. This work demonstrates a Ga₂O₃/WSe₂ mixed-dimensional heterojunction junction field-effect transistor (JFET) with positive and negative photoresponse regulatory functions by gate voltage. The device achieves a remarkable negative responsivity exceeding 425 mA/W. Additionally, benefiting from Fowler-Nordheim tunneling (FNT) behavior, the mixed-dimensional JFET exhibited an excellent negative response performance with response and decay times of 50.1 ms and 53.9 ms and a high I_OFF/I_ON ratio of 343 at V_ds=1 V and V_g=5 V under 635 nm illumination. Additionally, the JFET’s negative photoresponse is sensitive to both gate voltage and light intensity, which can be used to realize NAND logic gate and optical communication functions. These results unveil the promising potential of mixed-dimensional optoelectronic devices for optical communication, and logic device technologies.