Summary: | Lead-tin telluride alloy, Pb1-xSnxTe, is a narrow band gap group IV–VI semiconductor with NaCl-like crystalline structure. This material has interesting electronic properties, which makes it suitable for designing infrared photo detectors, diode lasers, and thermo-photovoltaic energy converters. In this project, we used spectroscopic ellipsometry in the spectral range of 0.74–6.5 eV to probe the linear optical response of Pb1-xSnxTe alloys in terms of the complex dielectric function. A strong optical response in the range of 0.7-2.0 eV arising from optical absorption was found. We studied eleven different samples of Pb1-xSnxTe of p-type origin with x values in the range (0 ≤ x ≤ 1). They were prepared by means of molecular beam epitaxy (MBE) on BaF2 substrates with 15mm2 area.
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