Electroluminescence properties of PbTe pn junctions fabricated under controlled Te vapor pressures

Electroluminescence properties of PbTe pn junctions grown under various tel lurium vapor pressures are investigated. For unintentionally doped pn junct ions, the luminescence bands corresponding to D-A pair and band to band tra nsition are observed. The luminescence intensity of the band to band transi tion has depended on tellurium vapor pressure, which suggests nonradiative transitions through nonstoichiometric defects forming deep levels. For pn j unctions with Bi-doped epitaxial layers, only one peak appears at 20 simila r to 25 meV below band to band-transition energy, which, probably, shows re combination through impurity levels or impurity band originating from Bi-do ping.