Anisotropy and High‐Efficiency Ultraviolet Polarized Photodetection of Wide‐Bandgap α‐AgGaP ₂ Se ₆ Microrods

ABSTRACT The exploration of materials combining a wide bandgap with high polarization sensitivity is of great significance for the field of photodetection. In this study, the lattice vibrational anisotropy and polarization‐sensitive photodetection performance of the one‐dimensional direct bandgap semiconductor α‐AgGaP 2 Se 6 were investigated. Through polarized Raman spectroscopy, temperature‐dependent Raman measurements, and density functional theory simulations, it was confirmed that most Raman peaks correspond to A g modes. The anomalous variation in polarized Raman intensity at 141.13 cm −1 is attributed to accidental degeneracy of vibrational modes at room temperature. Photodetectors fabricated based on this material demonstrate a dark current as low as 0.15 pA, a dichroic ratio of 2.45 under 405 nm laser illumination, and a maximum specific detectivity of 1.65 × 10 10 Jones. The photodetectors also exhibit good sublinear photoresponse and stable temporal response. With its outstanding polarization‐sensitive characteristics and weak‐light detection capability, α‐AgGaP 2 Se 6 is a highly promising candidate material for applications in wide bandgap polarization‐sensitive photodetection.