From bulk to surface: sodium treatment reduces recombination at the nickel oxide/perovskite Interface
The effect of sodium doping in NiO as a contact layer for perovskite solar cells
is investigated. A combined X-ray diffraction and X-ray photoelectron spectroscopy
analysis reveals that Na+ mostly segregates as NaOx/NaCl species around
NiO crystallites, with the effect of reducing interface capacitance as revealed by
impedance spectroscopy. Inspired by this finding, the NiO/perovskite interface
in perovskite solar cells is modified via insertion of an ultrathin NaCl interlayer,