The role of point defects and arsenic precipitates in carrier trapping and recombination in lowhyphen;temperature grown GaAs

摘要

GaAs epilayers were grown with a wide range of excess arsenic concentrations and subjected to various anneals to study the role of the point defects and arsenic precipitates in carrier trapping and recombination. Prior to anneal, the point defects rapidly trap photogenerated electrons and holesmdash;usually on subpicosecond time scales. However, full electronhyphen;hole recombination occurs on a significantly longer time scale. After anneal, the full electronhyphen;hole recombination lifetime appears to be greatly reduced, indicating that the arsenic precipitates play a significant role. copy;1996 American Institute of Physics.