Photothermal synergistic high-sensitivity self-driven vertical asymmetric Te/Bi₂Te₃/In₂O₃ heterojunction near-infrared imaging photodetector

Infrared detection and imaging devices have great potential in the fields of defense and security, medical monitoring, and food safety. As a novel method, photothermal assistants can expand the absorption in the case of low-angle dependence, which is one of the key factors in improving the performance of infrared detectors. Photo-heating accelerates the transfer of carrier, inducing a change in electrical conductance and exciting “hot” electrons promote a photoelectric response and extend the response photon energies well below the semiconductor band edge. However, photodetectors require cooling to prevent overheating and reduce thermal noise, thereby improving photoelectric detection. Therefore, it remains a formidable challenge to design a suitable heterojunction photodetector that can synergistically utilize optical and thermal energy. Here, a unique asymmetric Te/Bi₂Te₃/In₂O₃ heterojunction structure is designed by a simple physical deposition method, and a photothermal synergistic infrared detector is successfully fabricated. The Te/Bi₂Te₃/In₂O₃ heterojunction exhibits excellent self-driven photo-detection performance in the near-infrared wavelength bands of 850, 980, and 1050 nm, especially under prolonged laser irradiation at 850 nm. Under prolonged laser irradiation at 850 nm (0 bias), the heterojunction exhibits ultra-fast (response time < 55 ms), ultra-sensitive, and stable detection behavior, with a response rate as high as 0.4195 mA/W (R_i of 0.4724 mA/W, after 1,000 cycles), I_ph/I_dark is 281.55, and the detectivity as high as 4.296 × 10⁹ Jones. A high-resolution current image was obtained under 980 nm illumination at room temperature without bias. Such excellent optoelectronic properties make the heterojunctions of the asymmetric Te/Bi₂Te₃/In₂O₃ heterojunction a potential candidate for future infrared detection and imaging.