Strong photoluminescence caused by optical transitions between electron and hole Tamm-like interface states in ZnSe/BeTe heterostructures

We present an experimental data, which demonstrate a basically new mechanism of carrier radiative recombination in semiconductor heterostructures-recombination via Tamm-like interface states. Bright line was observed in photoluminescence spectra of periodical ZnSe/BeTe heterostructures at the energies, which correspond to the optical transitions between electron and hole Tamm-like interface states in studied heterosystem. Photoluminescence via Tamm-like interface states was observed for wide range excitation densities in the temperature range from 15K to 160K. It was found that for short-period ZnSe/BeTe heterostructures at low temperatures and at low excitation densities photoluminescence via Tamm-like interface states is much stronger than conventional interband radiative recombination.