Defect Engineering in Compound Semiconductor

The use of molecular doping sources was extended to achieve new and controlled defect structures. The controlled introduction of oxygen from the oxygen doping source, C2H52AlOC2H5, developed under the previous proposal were used to track the oxygen-based defect levels across the InxAl,Ga1-xP, and GaAsyP1-y band diagrams. These studies aided in assessment of the role of oxygen in the performance of devices made from these technologically important materials. The impact of the controlled development of the defect structure on the surface and interface morphology was determined. The work in this proposal utilized a strong combination of electrical and optical characterization techniques. Detailed measurements within the AlyGa1-y1-xInxP system has identified new defect structures exhibiting hysteretic effects impacting the performance in devices. A model suggesting that the these defects are due to the interaction of point defects with the changing local environment around extended defects was developed. Additional work in conjunction with Wayne State University, was carried out concerning the incorporation and activity of Er in GaAs and GaN hosts.