Enhanced Extraction Rates through Gap States of Molybdenum Oxide Anode Buffer

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• 作者：Binayak Dasgupta ; Wei Peng Goh ; Zi En Ooi ; Lai Mun Wong ; Chang Yun Jiang ; Yi Ren ; Eng Soon Tok ; Jisheng Pan ; Jie Zhang ; Sing Yang Chiam
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：May 9, 2013
• 年：2013
• 卷：117
• 期：18
• 页码：9206-9211
• 全文大小：311K
• 年卷期：v.117,no.18(May 9, 2013)
• ISSN：1932-7455

文摘

Molybdenum oxide (MoO₃) is a promising anode buffer layer (ABL) for high-performance organic photovoltaic (OPV) devices. However, the reasons for the enhanced performances remain unclear. In this work, we show that defect states play an important, if not dominating, role in improving the OPV performances. The changes in both the density of defect states and the work function of MoO₃ with annealing are shown and correlated with the OPV device performance. The increased defect densities improve the OPV performance through an enhanced hole extraction rate at the MoO₃/organic interface. The reduction in work function, however, reduces the interface field that can possibly lower mobility near the interface and reduce the electron-blocking effect. This plays a role in saturation of the device performance. This work, therefore, shows the importance of the defects in MoO₃ as an ABL and a dominance of defect-enhanced extraction over a field-enhanced extraction process.