Facially, Scalable Fabrication of Copper Telluride Photodetectors for Broadband UV-Visible Light Detection and Enabled Spectral Selectivity via Laser-Direct-Written Grating

Broadband UV-visible photodetection holds significant promise for advanced applications. However, achieving scalable fabrication and on-chip spectral-selectivity control remains challenging for emerging high-performance materials. Here, we develop a facile strategy for large-area copper telluride photodetectors, an underexplored transition metal telluride, via vacuum thermal evaporation and chemical vapor tellurization. The devices exhibit exceptional broadband UV-visible photoresponse, achieving responsivities of 210 mA/W at 365 nm and 200 mA/W at 465 nm. The direct bandgap of 2.6 eV enables robust UV-Visible detection, while optoelectronic characterization confirms p-type conductivity and photogating effects. Crucially, by enabling tunable spectral selectivity, femtosecond laser-direct-written gratings generate resonance peaks from 616 to 640 nm and enhance absorption below 700 nm, achieving a greater than twofold increase over planar films. This scalable fabrication, coupled with on-demand spectral engineering, positions copper telluride as a versatile material for next-generation microstructured optoelectronics.