Space charge effects in carrier escape from single quantum well structures

Steady-state photoluminescence and photocurrent efficiencies have been measured for single quantum well (SQW) p-i-n devices at forward bias over a range of temperature. These efficiencies depend on the competition between carrier escape from the well and both radiative and non-radiative recombination. From the efficiencies, two dimensionless parameters can be obtained; each depends only on the importance of escape relative to one of the two recombination processes. One of the parameters shows an unexpected thermal activation. An explanation is advanced in terms of band-bending caused by space charge in the well.