Undoped and Doped ZnO thin film based enhanced visible-light photodetector

Compound Semiconducting thin films are used in cutting-edge applications due to their fascinating and functional physical properties. Semiconducting metal oxides have numerous advantages in existing semiconductor technology due to their extraordinary physical, chemical, and electronic properties and their outstanding applications in different sensing and optoelectronic devices. The undoped ZnO (UZO) and Cu-doped ZnO (CZO) thin films were deposited by reactive sputtering using zinc (Zn) and copper (Cu) with argon (Ar) as the sputtering gas and oxygen (O2) as the reactive gas. The physical properties of as-deposited uniform, highly adhesive, and transparent ZnO thin films were investigated. A high response/recovery and self-powered undoped ZnO (UZO) and Cu-doped ZnO (CZO) thin film-based visible light photodetector fabricated on a cost-effective Si substrate using reactive co-sputtering. The CZO/n-Si exhibits a higher on/off ratio, responsivity and detectivity than UZO/n-Si. A relative study of CZO/n-Si and UZO/n-Si-based photodetector reveals the enhanced performance of CZO/n-Si photodetector with a high on/off ratio of ~300 with high specific detectivity 2.8×10¹⁰ Jones for 75 mW visible light. The prepared self-powered CZO/n-Si/Ag thin films-based visible-light photodetector paves the way for the development of high-performance photodetector designs.