Application of modulation spectroscopy for defining band gap of Cd1-xMnxTe solid solution

Abstract

The modulation spectroscopy was used for defining band gap of monocrystalline Cd1-xMnxTe solid solutions, the properties of which vary with molar composition x and the surface preparation quality. It was found that for such samples it is useful to measure differential transmission spectrum , the main peak of which is governed by the composition x and the substrate thickness d. Therefore, it is important to measure Eg(d) for at least three samples of the same composition and different thickness. Using these data, the band gap can be obtained by extrapolating Eg(d) dependence in a logarithmic scale up to intersection with the energy axis at lg d = 0, which corresponds to the sample thickness of 1 μm. Keywords: semiconductor, band gap, modulation spectroscopy.

Keywords

• напівпровідник, ширина забороненої зони, модуляційна спектроскопія