Conjugated organic optoelectronic materials have attracted significant attention due to their application in light emitting diodes,solar cells etc.For organic solar cells,interfacial modification between organic materials and electrode is an crucial issue since the charge extraction will obviously affect device performance greatly.Good interface properties will result in higher short circuit(Jsc)current and open circuit voltage(Voc)which are the most important factors for solar cells performance.Alcohol soluble organic materials attracted great interesting due to their unique solubility and electrode modification function.Through molecule structure design of alcohol soluble conjugated oligmer,we realized 9.2%efficiency.The results indicated that the molecule structure of the buffer layer could obviously affect the morphology of the active layer and lead the enhancement of the device efficiency.In further,we found that the pre-treatment of external bias could significant increase the efficiency of the devices with ion contained buffer layer.