Experimental studies of the recombination processes in II-VI semiconductors (bulk crystals and epilayers) at variable excitation levels

• Дата: 1999
• Автори: Brodyn, M.S., Shevel, S.G., Tishchenko, V.V.
• Формат: Стаття
• Мова: English
• Опубліковано: Інститут фізики конденсованих систем НАН України 1999
• Назва видання: Condensed Matter Physics
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/120545
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Experimental studies of the recombination processes in II-VI semiconductors (bulk crystals and epilayers) at variable excitation levels / M.S. Brodyn, S.G. Shevel, V.V. Tishchenko // Condensed Matter Physics. — 1999. — Т. 2, № 3(19). — С. 531-542. — Бібліогр.: 26 назв. — англ.

Low-temperature luminescence spectra under broad-scale variation of an excitation level Iexc are studied for ZnS/ZnSe single quantum wells (QW) and for CdS bulk crystals and epilayers. In the first case, the manifestations turn out to be of the heterointerface inhomogeneity - i.e. fluctuations of QW thickness. The position of the mobility edge for excitons localized by fluctuations is determined. In the second case the effect of the increase of Iexc is systematically studied not only for excitonic but also for impurity-related edge luminescence. Contrary to the earlier and commonly assumed expectations, up to the highest Iexc close to damage threshold no saturation of edge luminescence intensity was observed in bulk CdS crystals, whereas in a few thick epilayers such saturation did occur. The suggested qualitative explanation takes into account diffusion (non-diffusive transport) of carriers beyond the excited near-surface layer.