Preparation of Zn1-xMgxO films by radio frequency magnetron sputtering

II-VI widegap semiconductors such as ZnO are widely utilized in various ele ctronic and optical devices. To widen the band gap of ZnO, we conducted a s ystematic investigation of solid solution thin films of Zn1-xMgxO, a group of ternary compounds of the Zn-Mg-O system. We prepared the thin films by r adio frequency (RF) magnetron co-sputtering on fused silica substrates at r oom temperature. The thin films were a single phase of Zn1-xMgxO having the basic structure of ZnO at x less than or equal to 0.46 and the basic struc ture of MgO at x greater than or equal to 0.62, with segregation of the ZnO and MgxO phases at x = 0,58. The band gap of Zn1-xMgxO having the basic st ructure of ZnO increased from 3.24 eV at x = 0 (ZnO) to 4.20 eV at x = 0.46 . Transmittances of Zn1-xMgxO thin films were nearly equivalent to those of ZnO. Zn1-xMgxO has a wider band gap than ZnO and can be expected to provid e a useful window layer of solar cells that improves the overall efficiency by decreasing the absorption loss. (C) 2000 Elsevier Science S.A. AU right s reserved.