Excitation intensity dependence of photoluminescence from narrow 〈100〉- and 〈111〉A-grown ${\mathrm{In}}_x{\mathrm{Ga}}_{1-x}\mathrm{A}\mathrm{s}/\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}$ single quantum wells

We have used excitation intensity-dependent photoluminescence (PL) spectroscopy to study strained ${\mathrm{In}}_x{\mathrm{Ga}}_{1-x}\mathrm{A}\mathrm{s}/\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}$ $(x\approx 0.23)$ single quantum wells grown along the 〈001〉 and $〈111〉A$ directions. PL intensities from these two quantum-well samples exhibit a linear dependence on incident power density over the excitation intensity range examined. The linewidth of the emission from the 〈100〉 well is well described by band-filling effects as $I_{\mathrm{exc}}$ is increased. By careful analysis of the excitation intensity dependence of the 〈111〉 linewidth and the corresponding blueshift of the PL peak energy, the strain-induced piezoelectric field is estimated to be 70 kV/cm.