Simple Analytic Description of Collection Efficiency in Organic Photovoltaics
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- 作者：Brett M. Savoie ; Bijan Movaghar ; Tobin J. Marks ; Mark A. Ratner
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2013
- 出版时间：March 7, 2013
- 年：2013
- 卷：4
- 期：5
- 页码：704-709
- 全文大小：327K
- 年卷期：v.4,no.5(March 7, 2013)
- ISSN：1948-7185
文摘
The collection of charge carriers is a fundamental step in the photovoltaic conversion process. In disordered organic films, low mobility and disorder can make collection the performance-limiting step in energy conversion. We derive two analytic relationships for carrier collection efficiency in organic photovoltaics that account for the presence or absence of carrier-selective electrodes. These equations directly include drift and diffusive carrier transport in the device active layers and account for possible losses from Langevin and Shockley鈥揜ead鈥揌all recombination mechanisms. General relationships among carrier mobility, contact selectivity, recombination processes, and organic photovoltaic figures of merit are established. Our results suggest that device collection efficiency remains mobility-limited for many materials systems, and a renewed emphasis should be placed on materials鈥?purity.