MINORITY-CARRIER LIFETIME AND PHOTON RECYCLING IN N-GAAS

We are reporting here the hole or minority-carrier lifetime in n-type GaAs over a concentration range from 1 X 10(17) to 2 X 10(18) cm-3. The lifetimes were resolved by means of time-resolved photoluminescence using the time-resolved single photon counting technique. Diagnostic isotype double heterostructures were grown by metalorganic chemical vapor deposition. The isotype double heterostructures had confinement layers of composition Al0.3Ga0.7As. At a fixed majority-carrier concentration, active layer thicknesses were varied from approximately 0.25 to 10.0-mu-m. Using the accepted B coefficient as 2 X 10(-10) cm3/s, the photoluminescence lifetime is over an order of magnitude larger than the radiative lifetime. The data were interpreted in terms of photon recycling, and the experimental results agreed quite well with theory.