Effect of PCBM on the Photodegradation Kinetics of Polymers for Organic Photovoltaics
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- 作者：Andreas Distler ; Peter Kutka ; Tobias Sauermann ; Hans-Joachim Egelhaaf ; Dirk M. Guldi ; Daniele Di Nuzzo ; Stefan C. J. Meskers ; Ren茅 A. J. Janssen
- 刊名：Chemistry of Materials
- 出版年：2012
- 出版时间：November 27, 2012
- 年：2012
- 卷：24
- 期：22
- 页码：4397-4405
- 全文大小：454K
- 年卷期：v.24,no.22(November 27, 2012)
- ISSN：1520-5002
文摘
The photo-oxidation behavior of three different polymers鈥攏amely, poly(3-hexylthiophene) (P3HT), poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b鈥瞉dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (C-PCPDTBT), and poly[2,6-(4,4-bis(2-ethylhexyl)dithieno[3,2-b:2鈥?3鈥?d]silole)-alt-4,7-(2,1,3-benzothiadiazole)] (Si-PCPDTBT)鈥攊s investigated in neat polymer films and in blends with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) for different polymer:PCBM ratios. PCBM is shown to have both stabilizing and destabilizing effects, the extent of which is dependent on the type of polymer with which it is blended. Screening of the polymer from incident light by PCBM turns out to play an only minor role in the stabilization of P3HT. Quenching of the polymer excited states is also not a significant stabilization mechanism, as demonstrated by the comparison of the reduction of photo-oxidation rates to the extent of photoluminescence quenching by PCBM and 2,7-dinitrofluorenone (DNF). Photoinduced absorption spectroscopy reveals that the enhanced degradation of C-PCPDTBT in blend films with PCBM correlates with the population of the polymer triplet state via the polymer:PCBM charge-transfer state.