Investigation of Nano-Sized Sputtered Intrinsic Zinc Oxide Window Layer Properties for Thin Film Solar Cell (TFSC) Applications

The efficiency of solar cell devices depends greatly on the electrical performance of the cells. One effective approach to address this issue is by inserting a buffer layer between the p-type and n-type layers. In low-cost thin film solar cells, the window layer is positioned between the window and absorber layers, forming the p-n junction of the device. Buffer layers play a key role in optimizing thin film solar cells, as they help enhance the electrical properties by reducing carrier recombination and increasing the open-circuit voltage. In this study, intrinsic ZnO thin films were deposited using radio frequency (RF) magnetron sputtering at room temperature with thicknesses ranging from 50 nm to 100 nm. The impact of varying ZnO film thicknesses on the structural, optical, and electrical properties was analyzed to determine the optimal window layer quality. Surface topography was examined using atomic force microscopy (AFM), while energy-dispersive X-ray spectroscopy (EDX) was used to assess the atomic ratio of Zn to O. X-ray diffraction (XRD) analysis revealed that the ZnO thin films displayed a dominant (002) diffraction peak at 34.430° (2θ), indicating good crystallinity. Overall, the findings suggest that the ZnO thin films produced in this study have suitable properties for use as a window layer in thin film solar cell applications.