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

Electrical and optical properties of the conductive n-type skin layer prepared in high-resistivity CdTe:In by annealing at 400-600°C under Cd-rich overpressure were investigated. Slightly compensated donor level with the concentration N_D≈1.3×10¹⁶ cm^-3 and ionization energy E_D≈10 meV was evaluated from the Hall effect measurement. The electron mobility reached a maximum of 1×10⁴ cm²/Vs at 35 K after annealing at 600°C. Purification of the n-type layer was found out by photoluminescence measurement, where a reduction of the intensities of the emission lines related to alkali and silver acceptors was observed. The emission line at 1.584 eV, which is usually expected to characterize high-resistivity material, was detected in as-grown high-resistivity samples as well as in the conductive n-type layer.