Gate‐Tunable Spectral Response in β‐Ga2O3/Te Hybrid Photogating Structure for Ultrasensitive Broadband Detection

The increasing demand for multispectral information acquisition and the complexity of application environments have sparked a growing interest in broadband detection. However, achieving a high level of responsivity across a wide response range remains a significant challenge. Herein, an ultrasensitive broadband phototransistor based on hybrid photogating (HPG) structure is demonstrated, which consisted of a quasi‐2D beta‐phase gallium oxide (β‐Ga2O3) nanoflake as the carrier transport channel and a tellurium (Te) nanoflake as the photogating layer. Attributed to the strong doping influence of the Te nanoflake, a low off‐state current of pA level and a high on/off current ratio of ≈108 are obtained. Upon 255 nm wavelength illumination, the device exhibited an ultrahigh responsivity up to 3.82 × 106 A W−1 and a detectivity as high as 1.59 × 1014 Jones across a large gate voltage range. Notably, an exciting infrared response is obtained with a responsivity of 138 A W−1 and a detectivity of 3.70 × 109 Jones under the 1550 nm wavelength illumination, exclusively achievable when the gate voltage exceeded 4 V. Leveraging the gate‐tunable spectral response, an innovative model for secure optical communication was proposed. This work presents an efficient and feasible strategy for fabricating multifunctional optoelectronic devices. Herein, an ultrasensitive broadband phototransistor based on β‐Ga2O3/Te hybrid photogating (HPG) structure is demonstrated. The fabricated device exhibited a gate‐tunable spectral response characteristic as well as an excellent response performance in the ultraviolet and infrared wavebands. This work may provide an efficient and feasible strategy for fabricating multifunctional optoelectronic devices.