Atomic steps in thin GaInAs/lnP quantum-well structures grown by organometallic vapor phase epitaxy

Abstract

InP/GaInAs/InP quantum-well structures have been grown using atmospheric pressure organometallic vapor phase epitaxy (AP-OMVPE). The effects of growth parameters such as V/III ratio and substrate orientation have been studied. For thin wells the 10-K photoluminescence spectra show clearly resolved doublets or in some cases triplets. The energy separation of the peaks increases with decreasing well width down to a width of approximately 12 Å. 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. For the thin wells, where the individual photoluminescence peaks are resolved, the half-widths are extremely narrow. The value of <15 meV for the thinnest well is much better than observed previously for low pressure or AP-OMVPE and matches the results obtained by chemical beam epitaxy.