Temperature dependence of luminescence lifetime in Cu2O

The temperature dependence of the luminescence lifetime at 910 nm (so-calle d p-luminescence related to the presence of excitons and copper vacancies) was investigated. At low temperatures, the lifetime gradually increases up to about 130 K, but the decay curve suddenly splits to the double exponenti al form for higher temperatures. The strange temperature dependence was ana lyzed based on a model in which the oxygen vacancies act as the reservoir f or the beta-luminescence. The results and other observations suggest that C u vacancy level should not be so deep (0.55 eV) as currently believed. (C) 2000 Published by Elsevier Science B.V. All rights reserved.