THEORETICAL ANALYSIS OF THE VARIATION OF REFRACTIVE INDEX WITH BAND GAP IN SEMICONDUCTOR MATERIALS USING DIFFERENT MODELS

Abstract This study investigates the variation of the refractive index as a function of the band gap energy in semiconductor materials using several theoretical models, including Moss, Ravindra, Herve–Vandamme, Reddy, and Kumar–Singh. The results obtained from these models were systematically compared through tables and graphical representations to identify their consistencies and deviations. All models demonstrated a general trend of decreasing refractive index with increasing band gap, which is attributed to optical dispersion. The Herve–Vandamme model exhibited no intersection with the other models, reflecting its strong theoretical and physical foundation. In contrast, the Reddy and Kumar–Singh models showed closer agreement with experimental data, indicating their practical