Atomic steps at GaInAs/InP interfaces grown by organometallic vapor phase epitaxy

Abstract

InP/GaInAs/InP quantum well structures have been grown using atmospheric pressure organometallic vapor phase epitaxy (OMVPE). For thin wells the 10 K photoluminescence spectra show a clearly resolved doublet (or in some cases a triplet). The energy separation of the two peaks increase with decreasing well width down to a nominal width of approximately two to three atomic monolayers. For thinner wells the energy separation decreases with decreasing well width. The doublet is interpreted as being due to the photoluminescence from two wells differing in thickness by a single monolayer. A simple calculation for a finite quantum well describes the general features of the energy splitting versus well width. The half-widths of the two photoluminescence peaks for the thin wells, where the two peaks are resolved, are extremely narrow. The value of <15 meV for the thinnest well is much better than observed previously for low-pressure or atmospheric-pressure OMVPE and matches the results obtained by chemical beam epitaxy.