Formation of a DX center in InP under hydrostatic pressure.

Abstract

We have discovered a DX center in InP:S under hydrostatic pressure greater than 82 kbars. This defect exhibits the persistent photoconductivity typical of such centers. The optical ionization energy for this new DX center is between 0.86 and 1.02 eV, and we have measured the energy dependence of the optical absorption cross section. The thermal barrier for capture from the shallow donor state into the deep DX state is in the range 0.23--0.33 eV. We estimate that at zero pressure the energy of the DX center lies 0.51\ifmmode\pm\else\textpm\fi{}0.07 eV above the \ensuremath{\Gamma} conduction-band minimum.