Surface quantum wells

摘要

Surface quantum wells of InP have been grown, by organometallic vapor phase epitaxy, on top of graded GaxIn1minus;xP epitaxial layers. The surface quantum well is confined on one side by vacuum, and on the other side by the graded GaxIn1minus;xP. Photoluminescence measurements show two transitions for electronhyphen;hole recombination within the surface quantum well. Surface recombination appears to be saturated by the high density of carriers collected in the well, and plays a minor role. The bending of the conduction and valence bands in the GaxIn1minus;xP leads to a high collection efficiency of excess carriers near the surface, and suggests that high efficiency surface light emitters could be built in similar structures.