Controlling the blend morphology is one of the ways to achieve high power conversion efficiency in organic bulk heterojunction (BHJ) photovoltaic device. One sample yet effective method is ¡§ additive¡¨ approach, which involves the addition of a small concentrations of additive into the blend of donor/acceptor dissolved in solution. When adding small concentrations of additives in solution, we can change the donor/acceptor of internal micro-structure and films of morphology. In this work, we performed a systematic study of the effect of nanocrystals of phenolic additives, such as the small concentrations of 4,4'-Sulfonyldiphenol(BPDT), 4,4'-Dihydroxybiphenyl(BP) and Biphenyl-4,4¡¦-dithiol(BPS), on the nanoscals phase separation of and P3HT:PCBM blends and consequently, the power conversion efficiency(PCE) of the devices. The extent of the additive-induced phase separation and crystallize of P3HT is related to the additive acidity constant (pKa) and the degree of interaction between the additive and P3HT/PCBM, as evident from X-ray diffractmeter, UV-Vis spectrometer, Raman spectrometer and current density-voltage characteristic data. Lastly, PCE as increasing as 25% and short current increasing as 15% can be achieved in an optimally phase-separated blend due to an improvement in the charge dissociation and a dcrease in bimolecular recombination and parallel resistance.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0707111-174947 |
| Date | 07 July 2011 |
| Creators | Gong, Fang-Lin |
| Contributors | Wen-Yao Huang, Yu-Kai Han, Li-Yin Chen, Mei-Ying Chang, Wen-Jun Zheng |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0707111-174947 |
| Rights | not_available, Copyright information available at source archive |
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