Temperature-dependent optical spectra of single quantum wells fabricated using interrupted molecular beam epitaxial growth

Photoluminescence excitation (PLE) and temperature-dependent photoluminescence (PL) spectroscopies have been employed to interpret fine structure observed in the low-temperature PL spectra of GaAs/AlGaAs single quantum wells grown by molecular beam epitaxy under conditions of interrupted growth. Multiple peaks observed in the low-temperature PL spectra of similar samples grown by others have been held to be proof of monolayer steps in exceptionally smooth interfaces. We show that similar structure in the low-temperature PL spectra of our samples is not intrinsic. However, PLE or higher temperature PL spectroscopy yields unambiguous evidence for the model of interface smoothing due to growth interruption.