Analysis of the Moss and Ravindra relations

Abstract

Zntroduction Interrelations connecting the energy band gap and the high frequency refractive index are often required to estimate the high frequency refractive index of new materials. Therefore, attempts should be made to find new general relationships between these parameters. These parameters are of interest from the point of view of fundamental and technological considerations. Moss [l, 21 proposed a general relation based on the concept that in a dielectric energy levels are scaled down by a factor E$, i.e., n4E, = const (95).(1) The exponential behaviour of the above equation is similar to that of Moss [l, 21. This equation cannot be applied to materials with E, 5 0.Results and discussion Relation (4) is empirical in nature and it gives better values of n compared with the Ravindra relation. Equation (4) is applied to seventy semiconductors and n values are evaluated. Relevant data for the present work have been taken from Moss [2], Gupta and Ravindra [4], and Gopal [6]. The average percentage deviation calculated using the expression given below is also presented in Table 1, (nabs -nca,)/nobq x 100.Moss [2] critically examined and expressed that the Ravindra relation cannot occur if n 2 4.1 ( E , = 6.587) and also predicts unrealistic results for low n. In our analysis it is ') Anantapur 515003, India.

Energy gap–refractive index relations in semiconductors – An overview

“…In 1992, a relation similar to the Moss relation was proposed by Reddy and Anjaneyulu [19]. According to their formula, the relation is:…”

Band Structure, Charge Distribution and Optical Properties of AlPxSb1-x Ternary Semiconductor Alloys

“…Based on the values of n calculated from the Reddy and Anjaneyulu model 28 , the high-frequency dielectric constant (ε ∞ ) in AlP x Sb 1-x has been determined using the relation (6) The values of ε ∞ for AlSb and AlP calculated in the present work are 9.67 and 7.12, respectively. As compared to the experimental values of 9.88 (for AlSb) and 7.4 (for AlP) quoted in Ref.…”

“…27 are also shown for comparison. Note that a combination between the values of n determined for the end-point compounds AlSb and AlP indicates that the Reddy and Anjaneyulu model 28 is the most suitable to choose among the remaining models being considered in the present study. This is consistent with the result of Al-Assiri and Bouarissa 29 .…”

Study of Conductivity, Optical Constants and Solid State Parameters of Thiourea Zinc Sulphate Single Crystals

“…The optical band gap energy of the single crystals of TZS has been reported earlier as 4.77 eV from the UV-Visible spectrum [2]. The relation between optical band energy (E g ) and the refractive index (n) of the crystal is E g e n = 36.3 [6]. The calculated refractive index is then used to determine the reflectance(R) by applying the formula: to transmit light from 250 nm to above 800nm [7].…”