Comprehensive Study of Dopant Incorporation in ZnO and CuO Functional Metal Oxide Thin film Semiconductors: A Comparative Analysis of Traditional and Microwave Annealing Techniques for Enhanced Photovoltaic Applications by Modified C.B.D. Method

Abstract

This research presents a comparative analysis of dopant incorporation in zinc oxide (ZnO) and copper oxide (CuO) functional metal oxide thin film semiconductors, processed via traditional thermal annealing and microwave annealing techniques. Thin films were deposited using a modified chemical bath deposition (C.B.D.) method. Dopants (Al, Ga for ZnO; Na, Li for CuO) were introduced to enhance p‑type or n‑type conductivity and photovoltaic response. Microwave annealing (2.45 GHz, 300–600 W, 5–20 minutes) was compared with conventional thermal annealing (300–600 °C, 1–4 hours). Characterizations included X‑ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet‑visible (UV‑Vis) spectroscopy, Fourier‑transform infrared (FTIR) spectroscopy, and photovoltaic efficiency measurements. Results indicate that microwave annealing achieves superior dopant activation (30–45% higher carrier concentration), better crystallinity (lower FWHM in XRD), reduced processing time (up to 95% less), and lower thermal budget. However, non‑uniform microwave field distribution and equipment cost remain challenges. Current trends favour hybrid annealing and computational optimization. Historical evolution from furnace annealing to microwave processing is discussed. The study concludes that microwave annealing is highly promising for scalable, energy‑efficient fabrication of ZnO/CuO heterojunction photovoltaics.