DETERMINATION OF CONDUCTION-BAND TAIL AND FERMI ENERGY OF HEAVILY SI-DOPED GAAS BY ROOM-TEMPERATURE PHOTOLUMINESCENCE

Abstract

A line-shape analysis of room temperature photoluminescence (PL) spectra was carried out on Si-doped GaAs samples grown by molecular beam epitaxy. The electron concentration n of the samples ranges from 1.0 X 10(17) to 4.2 X 10(18) cm(-3). It was found that the conduction band tail eta(c) and the Fermi energy epsilon(f) measured from the conduction band minimum can be expressed as eta(c) = 2.0 X 10(-8)n(1/3)(eV) and epsilon(f) = -0.074 + 1.03 X 10(-7)n(1/3)(eV), respectively. The PL peak energy, at which the electron concentration per unit energy in the conduction band is maximum, can also be expressed as 1.426 + 2.4 X 10(-14)n(2/3)(eV). (C) 1995 American Institute of Physics.