OMVPE Growth of GalnAs/InP Quantum Well Structures

Abstract

ABSTRACTInP/GalnAs/InP quantum well structures have been grown using atmospheric pressure organometallic vapor phase epitaxy (AP-OMVPE). The optimum conditions for growth of extremely abrupt interfaces were studied. The optimum orientation was exactly (100). The growth had to be interrupted for 40 seconds at the first interface and 2 minutes at the 2nd interface to obtain the most abrupt interfaces. The narrowest photoluminescence half widths were obtained at the lowest values (31) of V/III ratio in the input vapor phase. These growth conditions allow the growth of wells as thin as <10Å with photoluminescence (PL) spectra consisting of doublets or triplets. The extremely narrow peaks correspond to regions of the quantum well differing in thickness by a single monolayer. The energy separations of the neighboring peaks are found to increase with decreasing well width until, at a thickness of approximately 12 Å, the separation begins to decrease rapidly with decreasing well width. The exciton binding energies in the quantum wells have also been measured using thermally modulated PL. The binding energy is found to increase with decreasing well width until a maximum value of approximately 17 meV is measured for a nominal well width of approximately 13 Å. For thinner wells the exciton binding energy is found to decrease with decreasing well width.