Laterally inhomogeneous barrier analysis of identically prepared Cd/CdS/n-Si/Au–Sb structures by SILAR method

In this study, CdS thin films have been deposited on n-Si substrate using a successive ionic layer adsorption and reaction (SILAR) method at room temperature. Structural properties have been investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. The XRD and SEM investigations show that films are covered well, polycrystalline structure and good crystallinity levels. The Cd/CdS/n-Si/Au–Sb structures (28 dots) have been identically prepared by the SILAR method. The effective barrier heights and ideality factors of these structures have been obtained from forward bias current–voltage (I–V) and reverse bias capacitance voltage (C–V) characteristics. The barrier height (BH) for the Cd/CdS/n-Si/Au–Sb structure calculated from the I–V characteristics have ranged from 0.664 eV to 0.710 eV, and the ideality factor from 1.190 to 1.400. Lateral homogeneous barrier height has been determined approximately 0.719 eV from the experimental linear relationship between BHs and ideality factors. The experimental BH and ideality factor distributions obtained from the I–V characteristics have been fitted by a Gaussian function, and their means of values have been found to be (0.683 ± 0.01) eV and (1.287 ± 0.05), respectively. The barrier height values obtained from the reverse bias C−2–V characteristics have ranged from 0.720 eV to 0.865 eV and statistical analysis yields the mean (0.759 ± 0.02) eV. Additionally, a doping concentration obtained from C−2–V characteristics has been calculated (8.55 ± 1.62) × 1014 cm−3.