Optical and Electrical Properties of ZnO:Cu Films Grown by DC Co Sputtering at Room Temperature Yolanda Rati1, Yasni Novi Hendri1, Robi Kurniawan2, Yudi Darma1*
1Quantum Semiconductor and Devices Lab., Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Ganesha 10, Bandung 40132, Indonesia, Indonesia
2Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jl. Semarang No.5, East Java 65145, Indonesia
E-mail: yudi[at]itb.ac.id
Abstract
We study the effect of increasing copper (Cu) dopant on the optical and electrical properties of ZnO films. Cu-doped ZnO (ZnO:Cu 3.8 and 7.0 wt%) films were grown using the DC co-sputtering technique at room temperature conditions on Si (100) substrate. The diffraction pattern shows a single-phase crystal (002) of ZnO wurtzite structure and the crystallite sizes of ZnO:Cu 7.0% (24.5 nm) smaller than ZnO:Cu 3.8% (26.1 nm). In UV-Vis analysis, two peaks of absorption were obtained i.e. ZnO and Cu2O, located at 378 nm and 494 for ZnO:Cu 2.8%, 385 nm and 550 nm for ZnO:Cu 7.0%. The photocurrent begins to increase at 2 V and continues to rise exponentially thereafter based on the I-V measurement. Cu dopant with a higher content of 7.0% reveals sensitivity two times better than Cu of 3.8%. These results reveal that ZnO:Cu is suitable for novel functional devices.
