Properties Of Ultra-Thin Radio-frequency Sputtered Aluminum Doped Zinc Oxide Thin Films For Solar Cell Applications

We optimized radio-frequency (RF) sputtering parameters for depositing low-thickness (ca 100 nm) aluminum-doped zinc oxide (AZO) for solar cell applications aimed at reducing optical losses commonly associated with transparent conducting oxides (TCO), which causes a significant reduction in the efficiency. X-ray diffraction (XRD) analysis and high-resolution scanning electron microscopy (HR-SEM) aided in studying the variations in the structure and morphology with deposition parameters and temperature. The optical characterizations using UV-Vis spectral measurements showed above 90% transmittance, with resistivity characterizations using four-point probe and Hall measurements. We defined a quality factor (QF) to characterize the performance of TCO layers, considering equally the resistivity and transmittance as they play vital roles in their TCO applications. The reported parameters produced films with lower resistivities and high QF for TCO applications with no use for post-deposition temperature treatments.