Hole distribution in InGaAsP 1.3-μm multiple-quantum-well laser structures with different hole confinement energies

We have investigated the hole distribution in strained InGaAsP multiple-quantum-well (MQW) structures by direct hole transport measurements with time-resolved photoluminescence spectroscopy. The results show that the hole transport time over the MQW primarily depends on the hole confinement energy in the wells and increases sharply with the well depth. A simple thermionic emission model indicates that the heavy holes escape predominantly over the light-hole barrier edge for strain-compensated MQW structures. The results are corroborated with observed laser performance data.