Features of experimental absorption spectra in the А<sub>3</sub>В<sub>5</sub> и А<sub>2</sub>В<sub>6</sub> semiconductor structures
The main aim of this work was experimental and theoretical investigation of absorption spectra in А<sub>3</sub>В<sub>5</sub> и А<sub>2</sub>В<sub>6</sub> structures based on the analysis of relating to the particular nature of their electronic band structures and investigated on the basis of the fundamental absorption edge caused by transitions of electrons from the valence band to the conduction band. To investigate the absorption edge HgCdTe samples were grown on CdZnTe (111)B substrates by Liquid Phase Epitaxy (LPE) and on GaAs (310) substrates by Metal Organic Compound Vapor Deposition (MOCVD) and Molecular Beam Epitaxy (MBE). They include vacancy doped epitaxial p-layer with acceptor concentration of N<sub>A</sub>≈ 10<sup>15</sup> сm<sup>-3</sup>, buffer and variband layers. In the field of energy ħω > E<sub>g</sub> for measured samples with single HgCdTe epitaxial layer, one can see good agreement in experimental and theoretical spectra. In the field of energy ħω < E<sub>g</sub> for measured samples with single HgCdTe epitaxial layer, grown by LPE, MOCVD, and MBE, one can see some deviation in experimental and theoretical spectra. This effect is to broaden the conduction band and form a band tail extending into the band gap. The experimental absorption spectra for epitaxial InGaAs on InP substrates have been show good agreement with theoretical spectra in working wavelength region, that shows the best crystal lattice perfection for A<sub>3</sub>B<sub>5</sub> materials as compared with A<sub>2</sub>B<sub>6</sub> and an applicability for high performance FPA production.