DEEP-LEVEL FORMATION AND HETEROJUNCTION BAND OFFSETS AT ZNSE GAAS INTERFACES/

We have used photoluminescence (PLS) to measure charge injection acros s the ZnSe/GaAs interface and subsequent near-band-edge (NBE) and deep level recombination as a function of interdiffusion and deep level fo rmation. We have performed these studies for a set of heterojunction g rowth parameters corresponding to a range of band offsets. Our earlier results provided evidence for growth-dependent deep level emission at the ZnSe/GaAs(100) heterointerface, new deep level formation at eleva ted temperatures associated with atomic interdiffusion across the junc tions, and major changes in recombination with the onset of defect for mation. Here we present simultaneous GaAs and ZnSe PLS measurements de monstrating the first order effect of deep level formation on the inte rnal photoemission of free carriers across the heterojunction and the dramatic difference in NBE recombination with defect formation for dif ferent stoichiometries of ZnSe growth. These features underscore the s ystematic role of deep levels in altering heterojunction dipoles and b and offset barriers to charge injection. (C) 1998 Elsevier Science B.V .