Determination of conductivity electron concentration in single-crystalline $n$-GaSb samples using FIR reflection spectra at $T$ = 295 K

A method is proposed for separately determining the concentrations of “light” and “heavy” electrons in $n$-GaSb. It is based on the analysis of reflection spectra in the far infrared region, taking into account the plasmon-phonon coupling. Calibration curves have been calculated that allow one to determine the concentrations of “light” and “heavy” electrons in GaSb using the frequency of high-energy coupled plasmon-phonon mode. For a series of $n$-GaSb samples the reflection spectra were measured and the concentrations of “light” and “heavy” electrons were determined at room temperature. Electrophysical Van der Paw measurements have been performed on the same samples at room temperature. By comparing the optical and Hall data, the ratios of the mobilities of “light” and “heavy” electrons (parameter $b$) were determined. This method of determining the value of the parameter $b$ is used for the first time.