SHAPE DEPENDENCE OF THE CONDUCTION BAND TAIL UPON DONOR CONCENTRATION IN GALLIUM ARSENIDE,
Abstract
The spectral dependence of the optical absorption in compensated gallium arsenide and of the spontaneous emission from p-n junctions of gallium arsenide indicates the existence of a donor band tail which extends into the forbidden gap. It was found that the shape of this band tail depends strongly on the donor concentration. The theory for transitions between a parabolic valence band and an exponentially-tailed conduction band contains a parameter ETA which describes the shape of this tail. The dependence of ETA on the donor concentration can be deduced by measuring absorption and electroluminescence of samples with different n-doping. Experimental data indicate that ETA = Cn to the 0.4th power. The same result was found theoretically under the assumption of a Gaussian tail having the width ETA. Experiments with a nearly saturated absorption in gallium arsenide can provide information about the density distribution of the tail and it can be checked experimentally whether the shape of the tail is described by an exponential or by a Gaussian function. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1967
- Accession Number
- AD0655112
Entities
People
- Horst R. Wittmann
Organizations
- United States Army Aviation and Missile Command