LOW CONCENTRATION GASB GROWN FROM SB-RICH SOLUTIONS BY LIQUID-PHASE EPITAXY IN THE PRESENCE OF ERBIUM

In this article, we report the growth of GaSb layers by introducing th e rare earth element Er into Sb-rich GaSb liquid phase epitaxy solutio ns. We find that the carrier concentration of GaSb layers can be effec tively lowered due to the gettering of residual impurities and the sup pression of complex acceptor defects in the presence of Er. Three inte nse sharp lines consisting of free exciton (FE) and excitons bound to neutral accepters (BE3 and BE4) dominate the low temperature photolumi nescence spectra of Er-doped GaSb. Zn-diffused Er-doped GaSb diodes ex hibit higher contact resistances and breakdown voltages due to lower c arrier concentration than for equivalent undoped diodes.