倒置异质结有机太阳能电池的电子传输层

制备了结构为ITO/BCP或Alq3(x=0,2,6,10,20,40 nm)/C60(50 nm)/Rubrene(50 nm)/MoO3(5nm)/Al(130 nm)的倒置异质结有机太阳能电池,其中BCP或Alq3作电子传输层。实验结果表明:当BCP或Alq3≤6 nm时,器件性能随电子传输层厚度的变化不大;当BCP或Alq3≥10 nm时,随电子传输层厚度的增加,含Alq3器件的性能衰减很快,含BCP器件的性能衰减相对较慢,且其开路电压保持不变。分析表明:当电子传输层较薄时,粗糙的ITO使电子较容易从C60注入到ITO;当电子传输层较厚时,BCP/C60之间的能带弯曲使二者之间几乎不存在势垒,含BCP器件性能较差主要源于BCP较差的电子迁移率,而含Alq3器件性能较差主要源于Alq3/C60之间的势垒。

Electron Transport Layers of Inverted Heterojunction Organic Solar Cells

Inverted heterojunction organic solar cells with a structure of ITO/BCP or Alq3(x=0,2,6,10,20,40 nm)/C60(50 nm)/Rubrene(50 nm)/MoO3(5 nm)/Al(130 nm) were prepared, in which BCP or Alq3 was used as electron transport layer. The experiment results show that when BCP or Alq3 ≤ 6 nm, device performance hardly changes with the increase of thickness of electron transport layers; When BCP or Alq3 ≥ 10 nm, device performance degrades quickly with the increase of thickness of Alq3, but slower and open circuit voltage remains unchanged with the increase of thickness of BCP. When electron transport layer is thin, the roughness of ITO makes electrons injection from C60 into ITO easy; when electron transport layer is thick, since band bending of BCP/C60 almost make that potential barrier between BCP and C60 does not exist, the bad device performance with BCP mainly comes from poor BCP electron mobility, that of one with Alq3 was primarily due to potential barrier between Alq3 and C60.