Photoluminescence mapping on InAs/InGaAs quantum dot structures

Photoluminescence (PL) mapping was performed at different temperatures on self-assembled InAs/InGaAs quantum dots structures created at different InAs QD growth temperatures (470-535°C). Two different behaviors in the quantum dot PL maps are observed: In first case a reduction of the PL intensity is accompanied with a monotonous "blue" shift of the luminescence maximum at 300 K and "red" shift at 80 K. In second case PL intensity variation matches a stable peak position of the PL maximum. Two different reasons are suggested to account for intensity variation of the quantum dot luminescence which depends on InAs QD growth temperature. It is shown that the optimal temperature range for the InAs QD growth in InGaAs/GaAs QW structures is 490-510°C.