Carrier screening effects in piezoelectric strained InGaAs/GaAs quantum wells grown on the [111]B axis

Excitation-power-dependent blue shifts in photoluminescence and electroluminescence are studied in piezoelectric strained layer multiple quantum wells (MQWs) incorporated in p-i-n diodes. By investigating MQWs with different geometric structures and controlling external bias it is demonstrated that, in contrast to previous studies, these blue shifts cannot always be attributed to long-range screening across a MQW and that screening must take place due to charge redistribution within individual wells. The results provide design rules to ensure this latter screening mechanism, which is subject to fast recovery.