Rubrene作电子传输层的异质结有机太阳能电池

以Rubrene为电子传输层(ETL),制备了结构为ITO/MoO3(5nm)/Rubrene(50nm)/C60(45nm)/Rubrene(0,3,5.5,9.5nm)/Al(130nm)的有机太阳能电池.与没有ETL的器件相比,含5.5nmRubrene的电池的开路电压、填充因子、功率转换效率分别从0.68V,0.488,0.315%增加到0.86V,0.574,0.490%.实验结果分析表明:热的Al原子直接沉积在C60上,破坏了C60层,形成高功函数的C60/Al阴极,弱化内建电场,降低电池性能;当插入ETL后,C60层得到保护,热的Al原子沉积破坏了Rubrene层,形成了缺陷态能级,提高电池的内建电场,促进了电子的传输.进一步的单电子电池实验表明,缺陷态能级低于C60的最低未占据分子轨道.

Heterojunction organic solar cells with Rubrene as electron transporting layer

Organic solar cells with structure of ITO/MoO_3(5 nm)/Rubrene (50 nm)/C_(60)(45 nm)/Rubrene (0, 3, 5.5, 9. 5nm)/Al(130 nm) were prepared. The rubrene layer near the AI cathode was used as the electron transporting layer.Compared with that of the control device without the electron transporting layer, the open circuit voltage, fill factor and power conversion efficiency of the device with 5.5 nm rubrene layer were increased from 0.68 V, 0. 488, 0. 315% to0.86 V, 0.574, 0.490% , respectively. The analysis of the experimental results shows that when hot AI atoms are directlydeposited on C_(60) layer, the C_(60) layer is undermined and a high work function is formed, which leads to a weaker built-in electric field and a poorer performance. When the rubrene layer is inserted, a significant improvement in device performance is achieved due to the formation of defect states in rubrene layer during A1 deposition. Further experimental results of single-electron devices show that energy levels of the defect states are lower than that of the lowest unoccupied molecular orbital of C_(60).