Direct measurement of band offset at the interface between CdS and Cu2ZnSnS4 using hard X-ray photoelectron spectroscopy

摘要: We directly and non-destructively measured the valence band offset at interface between CdS Cu2ZnSnS4 (CZTS) using hard X-ray photoelectron spectroscopy (HAXPES), which can measure electron state of buried because its large analysis depth. These measurements were made following real devices; CZTS(t = 700 nm), CdS(t = 100 nm)/CZTS(t = 700 nm), CdS(t = 5 nm)/CZTS(t = 700 nm) films formed on Mo coated glass. The spectra by HAXPES an photon energy 8 keV. value CZTS was estimated as 1.0 eV fitting spectra. conduction could be deduced 0.0 eV from obtained gap energies CZTS.