Radiative recombination across the Epsilon(0) and Delta(0) band gap in CdTe

Resonantly excited photoluminescence spectroscopy has been used to investigate radiative recombination across the Epsilon 0 plus Delta 0 band gap in undoped bulk CdTe. For excitation with photon energies slightly higher than the Epsilon 0 plus Delta 0 band-gap energy, luminescence is observed at this gap energy. This emission is interpreted as the radiative recombination of photocreated electrons and holes localized in the lowest conduction band and in the spin-orbit-split-off Gamma 7 valence band, respectively. Similar photoluminescence transitions across the Epsilon 0 plus Delta 0 gap are also observed in Cd-rich Cd chi Hg1 minus chi Te.