A Sensitive Visible Light Photodetector Using Cobalt-Doped Zinc Ferrite Oxide Thin Films

In this study, a highly sensitive trilayer photodetector using Co-doped ZnFe₂O₄ thin films annealed at 400 °C was synthesized successfully. Trilayer-photodetector devices with a film stack of 5 at % Co-doped-zinc-ferrite-thin-film/indium-tin-oxide on p⁺-Si substrates were fabricated by radio-frequency sputtering. The absorbance spectra, photoluminescence spectra, transmission electron microscopy images, and I-V characteristics under various conditions were comprehensively investigated. The outstanding performance of trilayer-photodector devices was measured, including a high photosensitivity of 181 and a fast photoresponse time with a rise time of 10.6 ms and fall time of 9.9 ms under 630 nm illumination. Therefore, the Co-doped ZnFe₂O₄ thin film is favorable for potential photodetector applications in visible light regions.