Strain-induced modifications of the band structure of In/sub x/Ga/sub 1-x/P-In/sub 0.5/Al/sub 0.5/P multiple quantum wells
IEEE Journal of Quantum Electronics
The effect of strain on the band structure of InxGa10xP-In0:5Al0:5P multiple quantum wells (MQW's) has been investigated from high-pressure and low-temperature photoluminescence measurements. The biaxial strain in the wells was varied between +0.6% compressive to 00.85% tensile strain by changing the well composition x from 0.57 to 0.37. Strain increases the valence band offsets in either tensile or compressively strained structures. Whereas relatively insensitive to tensile strain, the valence
... band offsets showed a strong dependence on the magnitude of the compressive strain. Good agreement is found between the measured valence band offsets and those predicted by the model solid theory, except for the largest compressively strained MQW's, for which the model calculations underestimate the measured valence band offset. Strain and the associated variations in composition also modified the separation among the well states associated with 0 1c ; L 1c , and X 1c . From these results, the bandgaps of each conduction band extrema were calculated in In x Ga 10x P for 0.37 < x < 0.57 and compared with the predictions of the model solid theory. Index Terms-Heterojunctions, photoluminescent materials/ devices, pressure measurements, quantum wells, semiconductor heterojunctions, strain. , where he conducted research on electrical and metallurgical characterization of metalsemiconductor contacts on Si and the III-V semiconductors. In 1984, he started a new research group at Colorado State University, Fort Collins, where he is currently a Professor of Electrical Engineering and involved in the growth of III-V heterostructures by gassource molecular beam epitaxy. He has taught short courses in the United States and Europe and has served in organizing committees for numerous conferences on the III-V semiconductors. Prof. Robinson is a member of the AVS.