Osmium related deep levels in indium phosphide

Deep energy levels arising from doping of n- and p-type InP with the 5d tra nsition metal Os are studied, using electrical and optical deep level trans ient spectroscopy. Electrically active Os-related level concentrations up t o 8.2 x 10(15) cm(-3) are observed representing up to 20% of the chemical c oncentration. Three prominent levels with low-electric-field activation ene rgies of E-V + 0.29, E-C - 0.32 and E-V + 0.53 eV, labelled OsA, Os1 and Os B, respectively, are identified. Double-cor relation deep level transient s pectroscopy measurements show strong dependence of carrier emission rates o n the electric field for all the three levels. All three levels exhibit a s tronger field effect than that reported for any other deep level in InP. Th e field effect can be interpreted in terms of a phonon-assisted tunneling m echanism, merging in a direct tunneling process at high field strengths for both Osl and OsA. Detailed data are obtained on the carrier capture cross sections and their temperature dependence for all three levels. In the case of OsA the data can be interpreted in terms of a multiphonon capture model .