Vertical carrier transport in InP-based quantum well laser structures

Carrier transport across the quantum wells has been measured for a number of InAlGaAs/InP and InGaAsP/InP quantum well laser structures by means of time-resolved photoluminescence. For the InAlGaAs structures, the interwell carrier transport times are ≈10–20 ps, while for the InGaAsP structures they are by a factor of five longer. The experimental results have been successfully described by a model which dynamically includes thermionic capture/emission over the quantum well interfaces and drift/diffusion in the barrier regions. The faster interwell carrier transport for the InAlGaAs structures is found to be a direct consequence of a smaller valence band offset in this material system.