Electrical and optical properties of In-doped CdTe after Cd-rich annealing

The electrical and optical properties of the conductive n-type surface layer created in high resistivity CdTe:In by annealing at 400-600degC under Cd-rich overpressure was investigated. Slightly compensated donor level with concentration N
_D
~1.3times10
¹⁶
cm
^-3
and ionization energy E
_D
~10 meV was obtained from the Hall effect measurement and the electron mobility reaches a maximum of 1times10
⁴
cm
²
/Vs at 35 K after annealing at 600degC. Purification of the n-type layer was confirmed by photoluminescence measurement, where decreasing of the emission lines related to alkali and silver acceptors were observed. The emission line at 1.854 eV, which is expected to characterize high resistivity material, was detected in as grown high resistivity samples as well as in the conductive n-type surface layer