Studies of ultrathin InGaAs quantum wells grown at different temperatures by magneto-photoluminescence

Here, the ultrathin InGaAs/GaAs single-quantum-well (QW) structures grown at different temperatures are studied using magneto-photoluminescence in magnetic fields of up to 15 T both parallel (B∥) and perpendicular (B∥) to the growth axis. The dimensionalities and the effective diameters are deduced from the low-field diamagnetic shift. The dimensionalities are approximately the same, 0.3, and the effective diameters obtained in B∥ are almost the same for the QWs grown at different temperatures. The effective diameter measured in B-∥ is larger than that in B∥ for the QW grown at high temperature while it becomes smaller than that in B∥ for the QW grown at the lowest temperature due to the exciton localization. The anomalous diamagnetic shift shows a cusp at approximately 4 T in B∥, and the high-field diamagnetic shift can be well-described as B^4/3 dependence based on the effective width well model.