Gerhard, A.; Harneit, W.; Brehme, S.; Bauknecht, A.; Fiedeler, U.; Lux-Steiner, M.Ch.; Siebentritt, S.: Acceptor activation energies in epitaxial CuGaSe2 grown by MOVPE. Thin Solid Films 387 (2001), p. 67-70
10.1016/S0040-6090(00)01841-1
Abstract:
Epitaxial CuGaSe2 layers were grown on GaAs (100) by MOVPE. Net carrier concentration and resistivity were examined with respect to temperature using a Van-der-Pauw geometry Hall setup. Net carrier concentrations from 2x10^14cm^-3 to 7x10^16cm^-3 were found with strong correlation to composition. All gallium rich samples show high compensation near 1. Thermal hole activation energies of 78+-10meV and 106+-10meV correspond to photoluminescence data from the same samples indicating two deep acceptors and one shallow donor. Mobilities up to 400cm^2/Vs at room temperature and 1450cm^2/Vs at 100K can be determined confirming high material quality.Measurement at lower temperatures was inhibited by carrier freeze out. We found mu {prop} T^-3/2 indicating acoustic phonon scattering to be the dominant mechanism over the whole measureable temperature range.