Influence of organic interface modification layer on the photoelectric properties of ZnO-based hybrid solar cells

[Display omitted] •Two amphipathic molecules are applied as interfacial modifier.•PCE of 1.41% is relatively higher among the reported ZnO-based HSCs without PCBM.•Surface density of states (DOS) of ZnO can decrease after modification.•Interfacial modification promotes exciton dissociation, reduces charge recombination. The organic-inorganic heterojunction interface of hybrid solar cells plays an important role on the cell performance. The properties of heterojunction interface were modulated by employing two small organic molecules. The results showed that the introduction of organic molecules could improve the compatibility between the organic and inorganic materials, accelerate excitons separation efficiency and suppress carriers recombination. The power conversion efficiency of device was improved from 0.23% to 1.41%. Furthermore, the charge lifetime and interface charge transfer/recombination mechanisms were analyzed in detail. The intrinsic factors affecting the cell performance were investigated by electrochemical impedance and open circuit voltage decay measurements.