Band Alignment Semimetal Heterojunction‐Based Ultrabroadband Photodetector for Noncontact Gesture Interaction with Low Latency

Abstract Non‐contact gesture recognition and interaction (NGRI) revolutionizes the natural user interface, fundamentally transforming human interactions with daily‐use technology. Conventional NGRI systems frequently encounter obstacles such as pronounced latency and environmental disturbances, including humidity or lighting conditions, resulting in compromised system fluidity and robustness. This study highlights the utilization of silicon‐based semimetal heterojunction photodetectors for precise gesture recognition and seamless human‐machine interaction. Through the application of band alignment theory and sophisticated TCAD simulation, heterojunction barriers are successfully optimized by fine‐tuning parameters including Si doping concentration and semimetal thickness. By strategically aligning vertical material growth and implementing vertical heterojunction configuration, a room temperature detector with exceptional sensitivity (specific detectivity (D*): ≈10¹¹ Jones), ultra‐broad spectral range (405–10600 nm), and rapid response time (≈ µs) is achieved. Harnessing its distinguished speed and sensitivity in detecting human infrared radiation, in conjunction with an advanced spatial‐temporal comparison algorithm and a multi‐channel high‐frequency sampling processing design, a NGRI system with low latency, high precision, minimal energy consumption, and versatility across diverse scenarios has been developed. The results pave the way for non‐contact sensor design and may further enhance the practicality and user experience of non‐contact human‐machine interaction systems.