Electron Accumulation on Metal Nanoparticles in Plasmon-Enhanced Organic Solar Cells
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- 作者：Michael Salvador ; Bradley A. MacLeod ; Angela Hess ; Abhishek P. Kulkarni ; Keiko Munechika ; Jennifer I. L. Chen ; David S. Ginger
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：November 27, 2012
- 年：2012
- 卷：6
- 期：11
- 页码：10024-10032
- 全文大小：633K
- 年卷期：v.6,no.11(November 27, 2012)
- ISSN：1936-086X
文摘
Plasmonic metal nanoparticles have been used to enhance the performance of thin-film devices such as organic photovoltaics based on polymer/fullerene blends. We show that silver nanoprisms accumulate long-lived negative charges when they are in contact with a photoexcited bulk heterojunction blend composed of poly(3-hexylthiophene)/phenyl-C61-butyric acid methyl ester (P3HT/PCBM). We report both the charge modulation and electroabsorption spectra of silver nanoprisms in solid-state devices and compare these spectra with the photoinduced absorption spectra of P3HT/PCBM blends containing silver nanoprisms. We assign a previously unidentified peak in the photoinduced absorption spectra to the presence of photoinduced electrons on the silver nanoprisms. We show that coating the nanoprisms with a 2.5 nm thick insulating layer can completely inhibit this charging. These results may inform methods for limiting metal-mediated losses in plasmonic solar cells.