Observation of theDXcenter in Pbhyphen;doped GaAs

摘要

Pb in GaAs introduces aDXcenterhyphen;like (metastable) defect level that is (229plusmn;16) meV above the Ggr;hyphen;conductionhyphen;band edge, in a similar energetic position to the Si and Sn relatedDXcenters in GaAs. The persistent photoconductivity effect quenches at approximately 50 K, indicating that the barrier to capture for the Pb and Sn dopants are similar. Despite the quite different atomic parameters of the Pb atom compared with the Sn atom, no significant chemical shifts have been found.