Space charge effects in carrier escape from single quantum well structures

Recently published data on the variation with applied bias and temperature of steady-state photoluminescence and photoconductivity from a series of GaAs/AlGaAs single quantum well p-i-n structures are subjected to detailed theoretical analysis, using phenomenological variables introduced in connection with these results. The data are interpreted as revealing the presence in the well of a space charge, which causes band bending and hence indirectly modifies carrier escape lifetimes. It is shown that the thermionic escape of holes can affect the electron tunneling escape lifetime so that the latter displays a thermal activation energy which is quantitatively similar to the hole well depth.