Strain-related excitionci in-lane optical anisotropy in (100) InGaAs/INAlAs/InP MQWs

摘要

Strained (x chemical bounds 0.48) and lattice-matched (x chemical bounds 0.53) In_xGa_(1-x)As/InalAs/InP (100) MQWs have been investigated byu photoreflectance. In the strained sample the relative intensities of the light-hole and heavy-hole excitonic transitions is different for the two different polarizations of the incident light parallel and perpendicular to the [0-1-1] direction. This polarization anisotropy is explained in terms of the spontaneous formation of "quantum wires" and the presence of anistropic sitrain due to spinodal-like phase decomposition of the INGaAs alloy in In-rich and Ga-rich regions.