Absence of ground state PLE peak in crescent-shaped AlGaAs/GaAs quantum wire superlattices

The optical properties of an AlGaAs (135 إ)/GaAs (45 إ) quantum wire superlattice (QWR-SL) grown on V-grooved substrate by flow rate modulation epitaxy are investigated using photoluminescence (PL) and PL excitation (PLE) spectroscopy. The QWR-SL showed step-like PLE spectra with the first step having almost no detectable PLE intensity which are completely different from the sawtooth-shaped PLE spectra of a 45 إ thick single QWR sample. The unusual optical properties of the QWR-SL are probably due to the interaction of the one dimensional QWR electronic state with optical field since the QWR electronic states are electronically isolated by the thick AlGaAs barrier layer in this sample.