Improved performance of polymer solar cells by using inorganic, organic, and doped cathode buffer layers

• Published in: Chinese physics B 2016-03, Vol.25 (3), p.428-433
• Main Author: 王桃红 陈长博 郭坤平 陈果 徐韬 魏斌
• Format: Article
• Language: English
• Subjects: Buffer layers; Cathodes; Devices; Electrodes; Organic materials; Performance enhancement; Photovoltaic cells; Solar cells; 太阳能电池; 掺杂; 无机; 有机发光二极管; 电池性能; 缓冲层; 聚合物; 阴极
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/25/3/038402

The interface between the active layer and the electrode is one of the most critical factors that could affect the device performance of polymer solar cells. In this work, based on the typical poly（3-hexylthiophene）：[6,6]-phenyl C61-butyric acid methyl ester （P3HT：PCBM） polymer solar cell, we studied the effect of the cathode buffer layer （CBL） between the top metal electrode and the active layer on the device performance. Several inorganic and organic materials commonly used as the electron injection layer in an organic light-emitting diode （OLED） were employed as the CBL in the P3HT：PCBM polymer solar cells. Our results demonstrate that the inorganic and organic materials like Cs2CO3, bathophenanthroline （Bphen）, and 8-hydroxyquinolatolithium （Liq） can be used as CBL to efficiently improve the device performance of the P3HT：PCBM polymer solar cells. The P3HT：PCBM devices employed various CBLs possess power conversion efficiencies （PCEs） of 3.0%-3.3%, which are ca. 50% improved compared to that of the device without CBL. Furthermore, by using the doped organic materials Bphen：Cs2CO3 and Bphen：Liq as the CBL, the PCE of the P3HT：PCBM device will be further improved to 3.5%, which is ca. 70% higher than that of the device without a CBL and ca. 10% increased compared with that of the devices with a neat inorganic or organic CBL.