Can Zou,Qing Liu,Lu Zhang,Xiao Tang,Xiaohang Li,Shuti Li,Shuti Li,Fangliang Gao,Fangliang Gao
This study pioneers a high-performance UV polarization-sensitive photodetector by ingeniously integrating non-centrosymmetric metal nanostructures into a graphene (Gr)/Al2O3/GaN heterojunction. Unlike conventional approaches constrained by graphene’s intrinsic isotropy or complex nanoscale patterning, our design introduces asymmetric metal architectures (E-/T-type) to artificially create directional anisotropy. These structures generate plasmon-enhanced localized electric fields that selectively amplify photogenerated carrier momentum under polarized UV light (325 nm), synergized with Fowler-Nordheim tunneling (FNT) across an atomically thin Al2O3 barrier. The result is a breakthrough in performance: a record anisotropy ratio of 115.5 (E-type, −2 V) and exceptional responsivity (97.7 A/W), surpassing existing graphene-based detectors by over an order of magnitude. Crucially, by systematically modulating metal geometry and density, we demonstrate a universal platform adaptable to diverse 2D/3D systems. This study provides a valuable reference for developing and practically applying photodetectors with higher anisotropy than ultraviolet polarization sensitivity.
Yunqi Zhao,Yipeng Song,Yanqiang Li,Wei Liu,Yang Zhou,Weiqi Huang,Junhua Luo,Sangen Zhao,Belal Ahmed
Birefringence is an important linear optical property of anisotropic crystals that plays a significant role in regulating light polarization. A new bialkali–rare earth metal sulfate, NaRbY2(SO4)4 compound, consisting of non-π-conjugated alkali metals and rare earth metal-centered dodecahedral YO8 has been synthesized. The structure analysis suggests that the three-dimensional (3D) structure of the compound is found to be attributable to the combination of dodecahedral YO8 and tetrahedral SO4 groups with Na+ and Rb+ located in the cavities. The ultraviolet, visible, and near-infrared (UV–vis–NIR) spectra reveal that the compound exhibits transparency at a wavelength of less than 200 nm. The observed birefringence of the compound is 0.045@550 nm, which is comparatively larger than that of most deep-ultraviolet (DUV) birefringent crystals. The birefringence mainly originated from the YO8 dodecahedron, which is suggested by first-principles calculations. This research work can provide a useful perspective to explore new DUV sulfates with excellent birefringence.