Temperature dependence of intrinsic carrier concentration and density of states effective mass of heavy holes in InSb

Abstract

From Hall measurements the temperature dependence of the intrinsic carrier concentration n i in InSb is determined between 200 K and the melting point of the compound (798 K). An empirical formula describing the temperature variation of n i is proposed. From the formula the temperature dependence of the density of states effective mass of heavy holes m d in InSb is determined. The effective mass increases from the minimum value of 0.37 m e at 225 K to a maximum value of 0.45 m e at 650 K. The obtained temperature variation of m d is smaller than found in earlier publications. The value of m d and its temperature dependence are also determined independently from the values of the valence band parameters and their temperature dependences. m d = 0.400 m e decreasing with temperature at the rate of about 10 −5deg −1 is obtained by this method. The discrepency of the results obtained by both methods is discussed and it is shown that the m d determined from the valence band parameters is more reliable. A by-product of the work is the determination of the valence band parameters which are: F = −97.8, H = −4.72 and G = −1.30.