The effect of oxygen on the excition spectra of A2B6 compounds

The exciton cathode luminescence and reflection spectra are studied for pure ZnSe with deviation from stoichiometry within a bilateral homogeneity region and a sharp change in the oxygen concentration from 3·10¹⁸ to 2·10²⁰ cm⁻³. It is confirmed that the exciton b and is not shifted and, consequently, that the forbidden band does not change with the oxygen concentration. This effect is interpreted on the basis of the interaction of oxygen with intrinsic point defects. It is found that dissolution, of oxygen enhances the excitonphonon interaction, which results in additional absorption within the A_ex-1LO or A_ex-2LO spectral region. It is shown that this effect is also characteristic of other compounds A₂B₆. Moscow Institute of Power Engineering, 14, Krasnokazarmennaya St., 111250, Moscow B-250, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 3, pp. 394–399, May–June, 1998.