Wang Ruizhi, Yan Xiaoliang, Yang Xiao, Wang Yuchen, Li Heng, Sheng Chuanxiang
School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Polymers (Basel). 2017 Aug 10;9(8):352. doi: 10.3390/polym9080352.
We used continuous wave photoinduced absorption (PIA) spectroscopy to investigate long-lived polarons in a blend of PbS quantum dot and regio-regular poly (3-hexylthiophene) (RR-P3HT). The charge transfer from RR-P3HT to PbS as well as from PbS to RR-P3HT were observed after changing the capping ligand of PbS from a long chain molecular to a short one. Therefore, PbS could be used to extend the working spectral range in hybrid solar cells with a proper capping ligand. However, we found that the recombination mechanism in the millisecond time region is dominated by the trap/defects in blended films, while it improves to a bimolecular recombination partially after ligand exchange. Our results suggest that passivating traps of nanocrystals by improving surface ligands will be crucial for relevant solar cell applications.
我们使用连续波光致吸收（PIA）光谱来研究硫化铅量子点与区域规整聚（3-己基噻吩）（RR-P3HT）混合物中的长寿命极化子。在将硫化铅的封端配体从长链分子变为短链分子后，观察到了从RR-P3HT到硫化铅以及从硫化铅到RR-P3HT的电荷转移。因此，通过适当的封端配体，硫化铅可用于扩展混合太阳能电池的工作光谱范围。然而，我们发现，在毫秒时间区域内的复合机制主要由混合薄膜中的陷阱/缺陷主导，而在配体交换后，它部分改善为双分子复合。我们的结果表明，通过改善表面配体来钝化纳米晶体的陷阱对于相关太阳能电池应用至关重要。
