BiAgOTe nanosheets with enhanced photoresponse ability: an experimental and computational study

Abstract

Oxychalcogenides containing metals have fascinating physical and chemical properties, making them well-suited for electronic and optoelectronic applications. In the present report, bismuth silver oxytelluride (BiAgOTe) samples synthesized by a microwave (MW) method were characterised for photodetector applications. The synthesized samples exhibited a polycrystalline structure through X-ray diffraction. The surface morphological study using field emission scanning electron microscopy revealed nanosheet/nano-walled morphologies in all samples, and energy dispersive X-ray analysis confirmed the constituent elements and their uniform distribution over the surface. The chemical composition and oxidation states of the elements were verified through X-ray photoelectron spectroscopy. The optical analysis using UV-visible spectroscopy revealed bandgap values ranging from 1.6 to 1.72 eV, confirming the semiconducting nature of the BAOT samples. Density functional theory calculations predicted low electron effective masses, suggesting high carrier mobilities. The samples demonstrated the photoresponse ability of the material under both dark and light conditions. Key photodetection performance metrics, including responsivity and detectivity, were computed to highlight the potential of BAOT materials as effective and reliable alternatives for advanced photodetector devices.