Hydrogen‐Assisted Recrystallization of Wafer‐Scale PbSe Films for Highly Uniform Mid‐Wave Infrared Detector Arrays

Mid‐wave infrared (MWIR) detection is essential for defense, industrial monitoring, and intelligent sensing, where compact, low‐cost, and large‐format imaging systems are increasingly required. Magnetron‐sputtered PbSe is attractive in this context because it enables scalable large‐area deposition and room‐temperature MWIR operation. However, sputtered PbSe typically forms fine‐grained polycrystalline films, in which grain‐boundary barriers and defect states degrade carrier transport and detector performance. Here, we develop a wafer‐scale hydrogen‐assisted recrystallization strategy for sputtered PbSe films. Hydrogen mediates grain‐boundary depinning by removing oxide‐related pinning constraints and passivating electronically active defect states, thereby promoting boundary migration and abnormal grain growth. Consequently, the carrier mobility increases nearly 18‐fold, from 4.52 to 80.32 cm 2 V − 1 s − 1 . The resulting hydrogen‐recrystallized PbSe films exhibit a peak specific detectivity of 3.5 × 10 9 Jones and an ultra‐fast response speed of below 1 µs at 3.5 µm. A 524‐pixel detector array fabricated across a 2‐inch wafer exhibits a pixel‐to‐pixel relative standard deviation of 6.69% in dark current, indicating that the recrystallization treatment is compatible with wafer‐scale device fabrication.