High performance gate tunable solar blind ultraviolet phototransistors based on amorphous Ga2O3 films grown by mist chemical vapor deposition

Abstract

Abstract Gallium Oxide (Ga2O3) for solar‐blind photodetectors (PDs) has drawing increasing research interest in recent years because of its natural wide bandgap. However, the traditional material growth methods are always complicated and the corresponding PD performance is also not good enough. In this work, amorphous Ga2O3 (a‐Ga2O3) thin film grown by mist chemical deposition applied as solar blind deep ultraviolet phototransistors (PTs) is investigated for the first time, to solve the problem of high cost and time‐consuming by traditional methods. Bottom‐gate a‐Ga2O3 three terminal thin film transistors (TFTs) are fabricated to boost their ultraviolet (UV) photodetection properties. Under the 254 nm UV illumination, the a‐Ga2O3 PTs demonstrates a very high responsivity of 2300 AW−1, external quantum efficiency of 1.12 × 106% and detectivity of 1.87 × 1014 Jones. Such field‐effect PTs with the ultrahigh performance address a significant step toward the feasibility and practicability of Ga2O3 PDs in the future applications.

Keywords

• Ga2O3 thin film
• mist‐CVD
• solar‐blind phototransistor