Enhancing the Optical and Structural Properties of CdTe Thin Films via Thermal Treatments for Solar Cell Applications

Abstract: This study examined the optical, structural, morphological, and electrical properties of polycrystalline cadmium telluride films fabricated using electrochemical deposition in a two-electrode system. Cadmium acetate is a source of cadmium and is one of the few precursors used to prepare cadmium tellurides. CdTe films were grown on glass substrates of fluorinated tin oxide (FTO), followed by thermal annealing at 200, 300, 350, and 400 °C. In addition, chlorination treatment was conducted at 400 °C. We analyzed various physical properties using characterization techniques, such as transmittance, X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDX), and a source meter. The increase in temperature after cadmium telluride deposition increased the optical transmittance, resulting in a progressive decrease in the optical energy bandgap from 1.74 to 1.49 eV. We computed various dielectric and optical constants using the Swanepoel and Herve-Vandamme models necessary for dielectric theory. Thermal annealing improved the crystallinity of the films (cubic structure), with 111 orientations being predominant. The heat treatment also determined and examined the various crystallinity parameters in detail. Surface morphology analysis revealed that the films exhibited homogeneity, high compaction, uniformity, and the absence of crystal imperfections. Keywords: CdTe, optical bandgap, refractive index, photovoltaic, absorber layer, electrochemical deposition. Title: Enhancing the Optical and Structural Properties of CdTe Thin Films via Thermal Treatments for Solar Cell Applications Author: DALAL N. ALHILFI, ALAA S. AL-KABBI International Journal of Novel Research in Physics Chemistry & Mathematics ISSN 2394-9651 Vol. 11, Issue 3, September 2024 - December 2024 Page No: 33-48 Novelty Journals Website: www.noveltyjournals.com Published Date: 23-December-2024 DOI: https://doi.org/10.5281/zenodo.14546920 Paper Download Link (Source) https://www.noveltyjournals.com/upload/paper/Enhancing%20the%20Optical%20and%20Structural-23122024-3.pdf