Temperature quenching of tunable tunneling recombination emission in AlxGa1-xAs n-i-p-i doping structures

Abstract

Competing emissions arising from e-h recombinations within the same layer (spatial-direct) and across layers (spatial-indirect) in AlxGa1-xAs n-i-p-i doping structures have been studied using photoluminescence (PL). The emission from spatial-indirect transitions dominate at low temperatures (<50 K). The cross-over temperature, Tx, at which the spatial-direct transition overtakes in intensity arising from spatial indirect transition, is found to be dependent on intrinsic layer thickness and the doped layer concentrations but weakly dependent on the excitation laser power density for values beyond 0.5 W cm-2. The spatial-direct transition is not observed when the intrinsic layer is not present. The ratio of intensities between the spatial-direct to the spatial-indirect transitions is described by an exponential function which is in agreement with theoretical prediction. © 1997 Elsevier Science Ltd.