Efficient hole-transporting layer MoO₃:CuI deposited by co-evaporation in organic photovoltaic cells

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• 作者：L. Barkat ; M. Hssein ; Z. El Jouad ; L. Cattin ; G. Louarn ; N. Stephant ; A. Khelil ; M. Ghamnia ; M. Addou ; M. Morsli and J. C. Bernè ; de
• 刊名：physica status solidi (a)
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：214
• 期：1
• 全文大小：1596K
• ISSN：1862-6319

文摘

In order to improve hole collection at the interface anode/electron donor in organic photovoltaic cells, it is necessary to insert a hole-transporting layer. CuI was shown to be a very efficient hole-transporting layer. However, its tendency to be quite rough tends to induce leakage currents and it is necessary to use a very slow deposition rate for CuI to avoid such negative effect. Herein, we show that the co-deposition of MoO₃ and CuI avoids this difficulty and allows deposition of a homogeneous efficient hole-collecting layer at an acceptable deposition rate. Via an XPS study, we show that blending MoO₃:CuI improves the hole collection efficiency through an increase of the gap state density. This increase is due to the formation of Mo⁵⁺ following interaction between MoO₃ and CuI. Not only does the co-evaporation process allow for decreasing significantly the deposition time of the hole-transporting layer, but also it increases the efficiency of the device based on the planar heterojunction, CuPc/C₆₀.