Thermally activated exciton transfer in GaAs1-xPx:N

The transfer of nitrogen-bound excitons to near-neighbor nitrogen-pair-bound excitons in GaAs1-xPx is investigated as a function of temperature. In contrast to GaP, where the transfer is rapid and efficient at low temperature, we find essentially no transfer at T=5 K. As the temperature is increased, the transfer rate for GaP grows only slowly, while that for GaAs1-xPx increases rapidly. By T=40 K, the rates are nearly the same. Two mechanisms are responsible for the transfer in the alloy: multiple trapping and variable-range hopping. © 1985 The American Physical Society.