THEORY OF LUMINESCENCE SPECTRA FROM S-DOPING STRUCTURES - APPLICATIONTO GAAS

A general procedure for calculating luminescence spectra from delta-do ping structures of semiconductors is developed. The electron and hole states are self-consistently calculated within the eight-band Kane mod el. Explicit results an obtained for p-type delta-doping wells and sup erlattices in GaAs. For a prototype superlattice (SL) it is demonstrat ed how the luminescence spectra of delta-doping structures depend on t heir self-consistent potentials, band structures, and oscillator stren gths of radiative recombination processes between extended electron an d confined hole states. Wave-vector conserving (direct) and nonconserv ing (indirect) transitions are considered. Luminescence spectra are ca lculated for a series of p-type delta-doping SL's, varying their sheet doping concentrations, doping spreads, and periods. A comparison with experimental spectra shows that direct transitions may be ruled out. The indirect spectra are dominated by an emission band below the gap w hose structures reflect the various occupied hole subbands. Increasing the temperature, the calculated hole emission bands become stronger, in contrast with experiment. This discrepancy is solved by means of a photoinduced electron confinement. [S0163-1829(98)05104-2].