This invention discloses a thin-film
solar cell with synergistic
passivation and field-effect modulation functions, and its fabrication method, belonging to the field of
solar cell technology. The core of this invention lies in introducing an ultrathin
barium titanate (BaTiO3) interlayer between the back
electrode and the CZTSSe absorber layer. This interlayer not only passively blocks
electron backflow and suppresses interfacial recombination by utilizing its large
conduction band offset with CZTSSe, but more importantly, it can induce BaTiO3 absorption during high-temperature selenization. 2+ Cu in CZTSSe + Non-equivalent cation migration and exchange occur, thereby actively constructing a directionally favorable cation migration and exchange-induced built-in
electric field (CME-field) within the quasi-neutral region of the absorber layer, synergistically promoting the collection of photogenerated holes. This invention achieves a synergistic effect of "passive blocking" and "active driving," significantly improving battery performance and increasing the
photoelectric conversion efficiency of battery devices to 14.00%.