Heavy hole doping of epitaxial thin films of a wide gap p-type semiconductor, LaCuOSe, and analysis of the effective mass

The high density hole doping (1.7×1021cm−3) for a wide gap (Eg=∼2.8eV) p-type semiconductor was achieved on 40nm thick Mg-doped LaCuOSe epitaxial films. These films exhibited distinct free carrier absorption, and the effective mass and momentum relaxation time were analyzed. Its small hole mobility [∼3.5cm2∕(Vs)] compared to the electron mobilities of wide gap n-type semiconductors is attributed to a heavy effective mass of 1.6±0.2me. Regardless of the heavy hole doping, a band filling effect was not observed. These results are discussed with a rigid band model and an acceptor band model.