Microscopic Photoluminescence Mapping of Si-Doped GaAs around Dislocations at Low Temperatures

摘要

Microscopic intensity variations of photoluminescence(PL) bands around dislocations were studied on Si-doped, liquid-encapsulated vertical boat grown GaAs at low temperatures. We measured the PL mappings for four emission bands: the 1.49eV band of frce-to-acceptor and donor-acceptor transitions involving Si_(As), the 1.33eV band associated with B_(As), the 1.15eV band due to V_(Ga) complex, and the 0.95eV band which appears commonly in n-type GaAs but has not yet been identified definitely. The PL intensity patterns of each emission band are explained based on the concept that defects have been gettered by the dislocations and that the area near the dislocations is more As-rich than that farther away.