为了提高双结叠层有机太阳能电池(OSCs)的性能, 我们对有机小分子叠层OSCs的中间层(IL)、阴极界面层(CL)和活性层进行了优化。首先,研究不同低功函数的金属纳米粒子(Mg、Ag、Al和Ca)作为IL对叠层OSCs性能的影响, 得到了最优的IL材料为0.1 nm厚的金属Al, 使得叠层OSCs的PCE提升了50.9%。其次, 研究了不同低功函数金属(Mg、Al和Ca)作为CL对叠层OSCs性能的影响, 并得到了最优的CL金属材料为Mg, 与Al作为CL的叠层OSCs对比, 采用Mg作为CL的器件PCE提升了20.7%。最后采用窄带隙材料DTDCTB取代中带隙材料boron subphthalocyanine chloride(SubPc)作为后子电池的活性层, 与仅采用SubPc的叠层OSCs相比, PCE提升了30.2%。当前后子电池均采用体异质结结构后, 最终叠层OSCs的PCE达到了4.04%, 与最初未优化前OSCs的PCE(2.1%)相比, 最优OSCs的PCE提升了92.4%。

The performance of double-junction tandem organic solar cells (OSCs) was improved by optimizing interlayer (IL), cathode interface layer (CL) and active layer. Firstly, by employing low work function metal nanoparticles (Mg, Ag, Al and Ca) as IL, the optimal performance was obtained in OSC with IL of 0.1 nm Al. Comparing to tandem OSCs without IL, the power conversion efficiency (PCE) of OSCs with Al IL was increased by 50.9%. Secondly, by employing different low work function metals (Mg, Al and Ca) as CL in tandem OSCs, the optimal performance was obtained in OSC with Mg CL. Compared with tandem OSCs with Al CL, PCE of OSCs with Mg CL was increased by 20.7%. Finally, narrow bandgap material DTDCTB was adopted to replace medium bandgap material boron subphthalocyanine chloride (SubPc) as active layer of the back sub-cell. Compared with tandem OSCs using only SubPc donor material, the PCE was increased by 30.2%. By using bulk heterojunctionstructure in both front and back sub-cells, PCE of tandem OSCs reached 4.04%. Compared with PCE (2.1%) of original non-optimized OSCs, the PCE of optimal OSCs was increased by 92.4%.