CdS Thin Film Characterization and Current Conduction Mechanisms in Pt/CdS/n-InP Heterojunction Diode

Abstract: This study analyzed the optical and structural properties of a CdS thin film grown on FTO and n‑InP substrates to understand its application in semiconductor technology. The bandgap of the CdS film was calculated as 2.432 eV. The film displayed uniform growth and coated the entire surface effectively, as observed through various microscopy and spectroscopy techniques. Furthermore, a Pt/CdS/n-InP/In he-terojunction was developed, and its temperature-dependent I–V characteristics were studied, revealing an ideality factor of 1.161 and a barrier height of 0.793 eV. These values suggested that the CdS interlayer affects the barrier height and ideality factor, particularly under varying temperatures, indicating barrier inhomogeneity. It has been found that the barrier height ranges from 0.337 eV at 120 K to 1.002 eV at 400 K, with corresponding ideality factor changes, demonstrating the Gaussian distribution of inhomogeneous barrier heights across different temperatures. © Pleiades Publishing, Ltd. 2025.