【摘要】 使用甲醇溶剂熏蒸聚(4,8-双[5-(2-乙基己基)噻吩-2-基]苯并[1,2-b;4,5-b’]双噻吩-2,6-双基-{4-(2-乙基己基)-3-氟代噻吩[3,4-b]噻吩-}-2-羧基-2,6-双基)(PTB7-Th)和聚[N,N’-双(2-辛基十二烷基)-1,4,5,8-萘二酰亚胺-2,6-双基-并-5,5’-(2,2’-双噻吩)](N2200)二元混合的活性层薄膜,发现其活性层和镀金探针间的接触电势差从37 m V升高到160 m V,表明活性层表面功函由4.71 e V降低到4.59 e V.XPS结果表明,由于甲醇和N2200之间更强的相互作用,在溶剂熏蒸过程中有更多的N2200分子扩散到薄膜表面.扩散引起了活性层表面功函的减小,使活性层和电极之间能级更加匹配,形成了更好的欧姆接触,使器件的功率转化效率提高了10%以上.更多还原

【Abstract】 The binary of blend poly{4,8-bis[5-(2-ethylhexyl)thiophen-2-yl]benzo[1,2-b∶4,5-b’]dithiophe-ne-alt-3-flu-orothieno[3,4-b]thiophene-2-carboxy-late}(PTB7-Th)∶poly{[N,N-bis(2-octyldodecyl)-napthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5’-(2,2’-bithiophene)}(N2200)(PTB7-Th∶N2200)active layer films were annealed by methanol solvent.The difference of contact potential between active layer and gold-coated tip were increased from 37 m V to 160 m V,which means the surface work function decreased from 4.71 e V to 4.59 e V.XPS result showed that more N2200 diffused to surface of active layer during vapor annealing because there was a stronger interaction between poor polar solvent methanol and N2200.Such diffusion lead to the decrease of work function which was beneficial to promote energy match between electrode and active layer and the formation of better ohmic contact,which resulted in the over 10% enhance of power conversion efficiency of corresponding organic solar cells.更多还原