Long‐term stable and high responsivity visible-ultraviolet photodetector of Se-doped CdO film on Si by spin coating

Abstract

Se-doped CdO thin films were prepared on p-Si substrates via spin coating. Morphological, structural and absorption measurements of CdO:Se film was performed. Then, a CdS:Se/p-Si heterojunction was produced by coating CdO:Se film on a p-Si substrate using spin coating method. From the I–V measurements, it has been seen that the device has a very good rectification feature in the dark, at room temperature. In order to investigate the performance of the device under light, a detailed analysis was performed by performing I–V measurements under ultraviolet (UV) light (365 and 395 nm, 10 mW cm−2) and different intensities of visible light (between 10 and 125 mW cm−2) as well as ambient light. It was observed that the CdO:Se/p-Si heterojunction performed well under both illumination conditions. The maximum responsivity and specific detectivity values were obtained as 0.72 and 4.47 A W−1 and 3.31 × 109 and 2.05 × 1010 Jones for visible and UV regions, respectively. It was also seen that the device exhibited very high performance and stability even after 160 days.