Excitonic states in ${\mathrm{C}\mathrm{d}\mathrm{T}\mathrm{e}/\mathrm{C}\mathrm{d}}_{0.74}{\mathrm{Mg}}_{0.26}\mathrm{Te}$ quantum wires grown on vicinal substrates

We have investigated excitonic luminescence from ${\mathrm{C}\mathrm{d}\mathrm{T}\mathrm{e}/\mathrm{C}\mathrm{d}}_{0.74}{\mathrm{Mg}}_{0.26}\mathrm{Te}$ quantum wires (QWR’s) grown on vicinal substrates. The temperature dependence of the radiative lifetime of one-dimensional exciton in the QWR’s was measured using time-resolved spectroscopy. The results are compared with that of two-dimensional exciton in ${\mathrm{C}\mathrm{d}\mathrm{T}\mathrm{e}/\mathrm{C}\mathrm{d}}_{0.74}{\mathrm{Mg}}_{0.26}\mathrm{Te}$ quantum well (QW). The radiative lifetimes of one-dimensional exciton in the QWR’s and two-dimensional exciton in the QW increase with T but show clearly different behavior. The observed radiative lifetime in the QWR’s obeys $T^{1/2}$ in a wide temperature range, confirming the one-dimensional nature in exciton thermalization. On the other hand, the radiative lifetime in the QW is linear with T. Furthermore, we observed clear biexciton formation at $\lesssim 10\mathrm{K}\mathrm{}$ in the QWR’s. The biexciton binding energy estimated from the line-shape analysis of the luminescence spectra for the QWR’s is 5.2 meV.