Electrical transport in a-As2Se3 containing metallic impurities

Significant changes of the hole drift mobility are observed in a-As₂Se₃ containing concentrations less than ～ 10²⁰ cm^?3 of metallic impurities (Mn, Fe, Ni, Cu, Zn, Ga, In, Tl and Na). Depending upon metal concentration the results suggest a modification of the hopping transport channel in Ga, In and Tl doped samples and the buildup of new traps that are either isoenergetic with the intrinsic trap population (Tl, Ga, In, Cu) or lie deeper in the gap (Mn, Fe, Ni, Cu). Trap-limited hopping transport provides a consistent explanation of the experimental data.