MOBILITY AND INFRARED ABSORPTION IN N-TYPE GALLIUM ARSENIDE

The relation between infrared absorption and mobility in gallium arsenide has been examined. The absorption theory of Haga and Kimura was used, as suggested by Vakulenko and Lisitsa, to calculate a theoretical drift mobility vs concentration curve for n-type gallium arsenide at 300°K. For concentrations above 1×1017 cm-3, this curve agrees well with that obtained from the Ehrenreich variational calculation. The Haga-Kimura theory was used also to predict that at temperatures between 77°and 300°K and concentrations above 1×1017 cm -3, the free-carrier absorption coefficient α in the far infrared (50-500 μm) takes the simple classical form α ∝Nλ2/μ, where N is the carrier concentration, λ the wavelength, and μ the drift mobility. This result suggests that far infrared absorption data may be used to directly calculate drift mobilities. © 1969 The American Institute of Physics.