Time resolved study of non radiative recombination in GaAs GaAlAs heterostructures

Nonradiative recombination (1/tnr) in GaAs GaAlAs structures was examined to assess the effect of GaAs layer thickness (d) on quantum well laser characteristics. Luminescence decay was observed with a streak camera. For d > 200A, nonradiative recombination is described by the equation 1/tnr = 1/tnrb + S/d, where S is the sum of the interface recombination velocity at the two interfaces. For d < 200A, S increases due to increasing leaking of carrier wave functions in the GaAlAs confinement layers. For a quantum well of 50A, the nonradiative lifetime is 2 nsec and increases the calculated threshold current from 110A/cm2 in SCH optimized quantum well lasers