Jafari Fatemeh, Patil Bhushan R, Mohtaram Fatemeh, Cauduro André L Fernandes, Rubahn Horst-Günter, Behjat Abbas, Madsen Morten
SDU NanoSYD, Mads Clausen Institute, University of Southern Denmark, Alsion 2, 6400, Sønderborg, Denmark.
Atomic and Molecular Groups, Faculty of Physics, Yazd University, Yazd, Iran.
Sci Rep. 2019 Jul 18;9(1):10422. doi: 10.1038/s41598-019-46854-w.
Bathocuproine (BCP) is a well-studied cathode interlayer in organic photovoltaic (OPV) devices, where it for standard device configurations has demonstrated improved electron extraction as well as exciton blocking properties, leading to high device efficiencies. For inverted devices, however, BCP interlayers has shown to lead to device failure, mainly due to the clustering of BCP molecules on indium tin oxide (ITO) surfaces, which is a significant problem during scale-up of the OPV devices. In this work, we introduce C doped BCP thin films as cathode interlayers in inverted OPV devices. We demonstrate that the interlayer forms smooth films on ITO surfaces, resulting from the introduction of C molecules into the BCP film, and that these films possess both improved electron extraction as well exciton blocking properties, as evidenced by electron-only devices and photoluminescence studies, respectively. Importantly, the improved cathode interlayers leads to well-functioning large area (100 mm) devices, showing a device yield of 100%. This is in strong contrast to inverted devices based on pure BCP layers. These results are founded by the effective suppression of BCP clustering from C, along with the electron transport and exciton blocking properties of the two materials, which thus presents a route for its integration as an interlayer material towards up-scaled inverted OPV devices.
浴铜灵（BCP）是有机光伏（OPV）器件中一种经过充分研究的阴极夹层，在标准器件配置中，它已证明具有改善的电子提取以及激子阻挡特性，从而实现了高器件效率。然而，对于倒置器件，BCP夹层已被证明会导致器件失效，主要原因是BCP分子在氧化铟锡（ITO）表面聚集，这在OPV器件放大过程中是一个重大问题。在这项工作中，我们引入了碳掺杂的BCP薄膜作为倒置OPV器件的阴极夹层。我们证明，由于将碳分子引入BCP薄膜，该夹层在ITO表面形成了光滑的薄膜，并且这些薄膜分别通过单电子器件和光致发光研究证明，同时具有改善的电子提取和激子阻挡特性。重要的是，改进后的阴极夹层使得大面积（100平方毫米）器件功能良好，器件良品率达到100%。这与基于纯BCP层的倒置器件形成了强烈对比。这些结果是由于碳有效抑制了BCP聚集，以及这两种材料的电子传输和激子阻挡特性，从而为其作为夹层材料集成到放大的倒置OPV器件中提供了一条途径。
