Enhanced SWIR photodetection in Te0.7Se0.3 alloy based phototransistors with spectral range of 1300 nm via dual-gate engineering

Short wavelength infrared (SWIR, 1-2.5 μm) photodetection plays a critical role in various applications, including night vision, remote sensing and optical communication. Conventional SWIR photodetectors, such as InGaAs and HgCdTe-based devices, face several challenges related to high fabrication costs, heterogeneous integration limitations of silicon Read-Out Integrated Circuit and environmental concerns. This study propose a Te_0.7Se_0.3 alloy thin film-based dual-gate phototransistor with a high-performance and cost-effective alternative for SWIR photodetection with spectral range of 1300 nm. By employing Te-Se alloy thin film as an active channel material, the both SWIR absorption and low off current state of thin film transistor (TFT) were successfully achieved. Furthermore, the dual-gate TFT device architecture, featuring a top electrode of Indium Tin Oxide with excellent SWIR transmittance (~ 77%) enhances charge carrier separation via an intrinsic built-in field. The proposed device exhibits an excellent SWIR detection performance, demonstrating a responsivity of 559.3 A/W at 1300 nm wavelength range.