Co‐Sputtered Sn:PbSe Films with In Situ Oxidation for Broad‐Spectrum Photodetection and Ultrafast‐Response Applications

Abstract PbSe exhibits significant potential for photodetection applications. Chemical doping is a well‐established method for modulating the band structure and carrier mobility of materials. In this study, an innovative strategy is reported for the first time that combines in situ oxidation with co‐sputtering deposition to fabricate and simultaneously oxidize tin‐doped PbSe films. The sensitized PbSnSe alloy films exhibit a narrow bandgap, high carrier mobility, excellent optical response characteristics, and broad detection capabilities (405–5000 nm). The maximum responsivity achieved by this detector is 3 A W ⁻¹ with a specific detectivity of 1.8 × 10 ¹¹ Jones. Furthermore, it demonstrates good optical response uniformity along with consistent mid‐infrared imaging capability at room temperature. Additionally, the detector showcases an ultrafast response speed exceeding 1 µs @808 nm and maintains a high switching rate greater than 10 ⁵ (I _on /I _off = 10 ⁵ ). This research provides novel insights into optimizing the performance of PbSe‐based infrared detection materials while highlighting their critical reference value in balancing preparation methods with material performance. Consequently, this work offers theoretical support as well as experimental foundations for designing high‐performance infrared detectors and establishes a comprehensive framework for developing highly stable infrared optoelectronic materials.