ABSTRACT
InP/GaP highly strained quantum wells (QWs) grown by metalorganic vapor phase epitaxy (MOVPE) are studied by photoluminescence (PL) spectroscopy. Four sharp and intense peaks from the InP/GaP highly strained QWs are clearly observed at 5 K. Considering the energy differences between the peaks, these are assigned as the no-phonon (NP) emission, TA x , LA x , and TC x phonon replicas. This shows that the optical transition of the InP/GaP highly strained QW is indirect under the compressive strain. Using a combination of PL and atomic force microscopy, it is found that the wetting layer continuously grows even after the InP island formation begins. Moreover, a calculation indicates that the thickness of the wetting layer finally approaches ~ 2 ML.
