Fig. 3: Electronic properties of CuSCN layers and hole-transport mechanism.

a Mott-Schottky plot of CuSCN layers tested in 1 M Na₂SO₄ solution. b J^0.5-V plots for CuSCN-based hole only devices. c Enlarged valence band spectra with shadowed area denoting the band-tail states. d Band energy diagrams showing the band-tail assisted hole transport between Cu₂O and CuSCN.