Photoconductivity Studies of Cr Deep Acceptors in InP

Abstract

Photoconductivity has been observed from Cr-doped InP at temperatures between 6 and 300 K. Photoconductive onsets have been observed at 0.47 eV at 6 K (0.40 eV at 300 K), and at 0.93 eV at both 6 and 300 K. The structure above 0.93 eV is found to be suppressed by compensation of the Cr with shallow Sn donors introduced by nuclear transmutation doping. The two onsets are attributed to photoexcitation into and out of the dominant Cr trap located 0.40 eV below the conduction band at 300 K. An additional broad structure is observed at 0.8 eV which is thought to be due to an internal transition of the Cr ion.