An injection type electro-luminescence in ZnSe crystal has been studied by using ZnSe-SnO2 hetero-junction at 20°K. In the emission peak observed around 2·70 eV, a clear energy shift toward the higher energy side with increasing injection current density has been found at low temperatures, which could be associated with the D-A pair (donor-acceptor pair) recombination process. The energy sum of the donor and acceptor activation is estimated to be larger than 137 meV. In the higher temperature region, this emission line turns out due to the 'free-to-bound' recombination, and the related acceptor ionization energy is considered to be ∼120 meV. By taking into consideration the energies of bound exciton emission, the exciton localization energies and the related donor and acceptor ionization energies are evaluated.
ASJC Scopus subject areas
- 化学 (全般)