Open AccessTheoretical prediction of the plasma frequency and Moss-Burstein shifts for degenerately doped In{sub x}Ga{sub 1{minus}x}As
Author(s) -
J.E. Raynolds,
G.W. Charache,
C. B. Geller,
Todd Holden,
Fred H. Pollak
Publication year - 1998
Language(s) - English
Resource type - Reports
DOI - 10.2172/307867
Subject(s) - doping , band gap , effective mass (spring–mass system) , condensed matter physics , electronic band structure , plasma , atomic physics , materials science , physics , quantum mechanics
Theoretical predictions for the plasma frequency and Moss-Burstein shift (optical band gap) of degenerately doped (n > 10{sup 19} cm{sup {minus}3}) In{sub x}Ga{sub 1{minus}x} As are presented. This system is of interest because it possesses desirable optical properties for thermophotovoltaic (TPV) applications. The studies presented are based on electronic band structures calculated using the Full Potential Linearized Augmented Plane Wave (FLAPW) method which includes non-local screened exchange (sX-LDA) and spin-orbit effects. The plasma frequency and Moss-Burstein shift are calculated vs. doping assuming a rigid band approximation (i.e. conduction band filling of the undoped bands). The doping dependence of the effective mass (band non-parabolicity) plays an important role at the high dopings considered here. This effect leads to a maximum in the plasma frequency vs. doping (2--3 {times} 10{sup 14}/s) and a significant departure from the constant effective mass prediction for the optical band gap vs. doping. These calculations are in good agreement with measurements