Mechanism for Oxygen-Enhanced Photoconductivity in Rubrene: Electron Transfer DopingThis publication involves research sponsored by the U.S. Department of Energy under grant no. DE FG02-04ER 46118 and
详细信息 查看全文
- 作者：Ashok J. Maliakal ; Judy Y.-C. Chen ; Woo-Young So ; Steffen Jockusch ; Bumjung Kim ; Maria Francesca Ottaviani ; Alberto Modelli ; Nicholas J. Turro ; Colin Nuckolls ; Arthur P. Ramirez
- 刊名：Chemistry of Materials
- 出版年：2009
- 出版时间：November 24, 2009
- 年：2009
- 卷：21
- 期：22
- 页码：5519-5526
- 全文大小：864K
- 年卷期：v.21,no.22(November 24, 2009)
- ISSN：1520-5002
文摘
The oxygen-enhanced photoconductivity observed in crystalline rubrene is investigated using electron paramagnetic resonance (EPR) spectroscopy and steady-state and time dependent photoconductivity (PC) measurements. The EPR data indicate the presence of rubrene radical cation and oxygen radical anion pairs formed within the crystalline structure when rubrene is irradiated in the presence of oxygen. Radical lifetimes determined using EPR spectroscopy correlate well with transient PC data and provide strong evidence that the rubrene radical cation is the charge carrier responsible for enhanced conduction. This process is reversible, although photodegradation is also observed. The oxygen-enhanced PC of rubrene is thus explained by an electron transfer mechanism that generates radical cation “hole” carriers within the crystal via the oxygen acceptor.