An ultra-violet and infrared dual-band photodetector using a Ga₂O₃ thin film and HgTe colloidal quantum dots

Dual-band photodetection of ultraviolet (UV) and infrared (IR) light is an advanced technology aimed at simultaneously or selectively detecting signals from these two distinct wavelength bands. This technique offers broad application prospects, particularly in environments requiring multispectral information. In this work, a solar-blind UV photodetector made from an amorphous Ga₂O₃ (a-Ga₂O₃) thin film was combined with a short-wave infrared photodetector made from a HgTe colloidal quantum dot (CQD) film. The photodetector exhibited a high responsivity of up to 1808 A W⁻¹, detectivity of 3.88 × 10¹⁴ Jones, and an external quantum efficiency of 8.8 × 10⁵% at UV wavelength as well as a responsivity of 0.25 A W⁻¹, detectivity of 1.45 × 10¹⁰ Jones, and an external quantum efficiency of 15.5% at short-wave infrared wavelength. Furthermore, corona discharge detection using this photodetector was demonstrated.