Photocurrent analysis of organic photovoltaic cells based on CuPc/C60 with Alq3 as a buffer layer

The performance of an organic photovoltaic(OPV) cell based on copper phthalocyanine CuPc/C60 with a tris(8-hydroxyquinolinato) aluminum(Alq3) buffer layer has been investigated.It was found that the power conversion efficiency of the device was 1.51% under illumination with an intensity of 100 mW/cm2,which was limited by a squareroot dependence of the photocurrent on voltage.The photocurrent-optical power density characteristics showed that the OPV cell had a significant space-charge limited photocurrent with a varied saturation voltage and a three quarters power dependence on optical power density.Also,the absorption spectrum was measured by a spectrophotometer,and the results showed that the additional Alq3 layer has a minor effect on photocurrent generation.     

TFTTP作为阴极缓冲层提高有机薄膜太阳能电池的内建电场和载流子收集效率

采用一种新型的电子传输材料TFTTP作为阴极缓冲层提高基于SubPc/C60异质结的有机薄膜太阳能电池的性能. 通过在有机活性层和金属电极之间加入TFTTP界面层,器件的能量转换效率提高了约30%. 系统研究了器件的二极管特性、光电流特性以及内部的光场分布情况,结果表明,TFTTP阴极缓冲层的引入可以有效地提高器件的内建电场,进而增加电荷转移激子的分离效率. 通过使用TFTTP作为阴极缓冲层,在C60/金属界面形成良好的欧姆接触,降低了界面接触电阻,有利于自由载流子的收集.     

Detailed analysis of ultrathin fluorescent red dye interlayer for organic photovoltaic cells

The influence of an ultrathin 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) fluorescent dye layer at donor/acceptor heterojunction on the performance of small-molecule organic photovoltaic (OPV) cell is studied. The structure of OPV cell is of indium-tin oxide (ITO)/copper phthalocyanine (CuPc)/DCJTB/fullerene (C₆₀)/bathophenanthroline (Bphen)/Ag. The results show that open circuit voltage (V_OC) increases to 0.57 V as the film thickness of DCJTB layer increases from 0.2 to 2.0 nm. By using an equivalent circuit model, the enhancement of V_OC is found to be attributed to the reduced reverse saturation current density (J_S) which is due to the lower highest occupied molecular orbital (HOMO) level in DCJTB than that in CuPc. Also, the short circuit current density (J_SC) is affected when the DCJTB layer becomes thicker, resulting from the high series resistance R_SA due to the low charge carrier mobility of fluorescent red dye.     

使用不同阴极缓冲层提升性能的反型有机太阳能电池

使用含Al_q3、Bphen、BCP、HATNA和Cs₂CO₃作为阴极缓冲层,制备了基于SubPc和C₆₀的反型平面异质结有机太阳能电池. 比较了有机阴极缓冲层的最低未占有分子轨道和电子迁移率对有机太阳能电池性能的影响. 结果显示,Al_q3、Bphen和HATNA能够大幅度提升器件的性能. 使用退火过后的HATNA作为阴极缓冲层获得了最高的效率,比没有阴极缓冲层的器件提升了7倍. 另外,使用空间电荷限制电流理论进行仿真的结果表明,通过加入HATNA作阴极缓冲层,反型有机太阳能电池结构中处于有机/电极界面处的肖特基势垒降低了27%.     

TFTTP作为阴极缓冲层提高有机薄膜太阳能电池的内建电场和载流子收集效率

采用一种新型的电子传输材料TFTTP作为阴极缓冲层提高基于SubPc/C₆₀异质结的有机薄膜太阳能电池的性能. 通过在有机活性层和金属电极之间加入TFTTP界面层,器件的能量转换效率提高了约30%. 系统研究了器件的二极管特性、光电流特性以及内部的光场分布情况,结果表明,TFTTP阴极缓冲层的引入可以有效地提高器件的内建电场,进而增加电荷转移激子的分离效率. 通过使用TFTTP作为阴极缓冲层,在C₆₀/金属界面形成良好的欧姆接触,降低了界面接触电阻,有利于自由载流子的收集.