Self-driven near-infrared photodetectors based on Sb2Te3/n-Si heterostructures with low dark current and fast response

Abstract

Near-infrared (NIR) photodetectors profoundly influence numerous domains, including military security, biomedical applications, and remote sensing technologies. However, the majority of cutting-edge infrared photoelectric materials are prohibitively expensive and incompatible with the CMOS process, such as InGaAs. Antimony telluride (Sb₂Te₃), a third-generation topological insulator (TI), has demonstrated considerable potential for infrared detection due to its high absorption and mobility. Notably, Sb₂Te₃ is recognized as a promising candidate for the monolithic integration with silicon, furthering its applicability. By leveraging magnetron sputtering and rapid annealing, we have developed an antimony telluride/n-silicon (Sb₂Te₃/n-Si) heterojunction photodetector with an ultrafast response time (τ_on ∼ 160 μs, τ_off ∼ 50 μs), extremely low dark current (10⁻¹¹ A), and an enhanced light-on/off ratio of up to 10³. The device exhibits a remarkable detectivity of 1.2 × 10¹¹ Jones and a self-powered photo-response characteristic across the 405–1310 nm range. In addition, the fabricated 3 × 3 pixel device array shows high uniformity and reproducibility. This presents a promising approach for advancing the development of superior and low-cost photodetectors.