New non-conjugated small molecules (C4-OH and C6-OH) were synthesized and applied to the inverted organic solar cells (OSCs) as the cathode interlayer (CIL). The power conversion efficiencies (PCEs) of 9.35 and 9.21% were obtained in the device based on ZnO/C4-OH and ZnO/C6-OH, which are better than those of pristine ZnO (8.74%). The work function of ZnO/C4-OH and ZnO/C6-OH are also decreased from -4.5 to -4.27 eV and -4.37 eV, respectively. Consequently, OSCs with two small molecules exhibited enhanced photovoltaic properties due to the formation of interface dipole.