High-Performance Vis–NIR Photodetectors Based on Two-Dimensional Bi2Te3 Thin Film and Applications

Two-dimensional materials have excellent optoelectronic properties and have great significance in the field of photodetectors. We have prepared a thin film photodetector based on bismuth telluride (Bi2Te3) topological insulator using dual-temperature-zone vapor deposition technology. Due to the high-quality lattice structure of Bi2Te3 and the uniform and dense surface morphology of the Bi2Te3 thin film, the device exhibits excellent photoelectric response and Vis–NIR spectral range. Under 405 nm illumination, the responsivity is 5.6 mA/W, the specific detectivity is 1.22 × 107 Jones, and the response time is 262/328 ms. We designed a photodetector single-point scanning imaging system and successfully achieved high-resolution imaging at a wavelength of 532 nm. This work provides guidance for the application of two-dimensional materials, especially Bi2Te3, in the fields of photodetectors and imaging.