Electrical properties of layer semiconductor p-GaSe doped with Cu

Measurements of Hall effect and deep-level transient spectroscopy have been made on Cu-doped p-GaSe. The moderately deep acceptor and shallow acceptor levels located at 0.13 and 0.04 eV above the valence band are obtained from the temperature dependence of the hole concentration. The hole-trapping level at 0.14 eV above the valence band is detected by deep-level transient spectroscopy and shows almost the same position as the moderately deep acceptor level. We find that the shallow acceptor level of 0.04 eV is attributed to Cu atoms, whereas the moderately deep acceptor level of 0.13 eV is governed by the defects or defect complexes.