Cathode interlayer-free organic solar cells with enhanced device performance upon alcohol treatment. Issue 26 (7th June 2019)

• Record Type: Journal Article
• Authors: Chen, Xuebin; Zhu, Bei; Kan, Bin; Gao, Ke; Peng, Xiaobin; Cao, Yong
• Is Part Of: Journal of materials chemistry. Volume 7:Issue 26(2019)
• Page Start: 7947
• Page End: 7952
• Publication Date: 2019-06-07
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9tc01039d
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Solvent treatment was used to simplify the device structure and enhance the device performance of porphyrin-based small molecule solar cells. Abstract : An organic solar cell (OSC) usually contains a cathode interlayer (CIL) to enhance the device performance. However, if a cell without a CIL (CIL-free) still shows high performance, the cost of the cell can be reduced. In this study, we demonstrate that methanol soaking of the active layers is efficient to improve the performance of porphyrin small molecule-based bulk heterojunction photovoltaic devices. Compared with the CIL-free devices without treatment, the champion power conversion efficiency (PCE) of the CIL-free OSCs upon 15 s MeOH soaking treatment is improved by 18.7% from 7.55% to 8.96%. The PCE is even higher than those of the devices with widely used PFN-Br cathode interlayers (PCE: 8.55%) (PFN-Br: (poly[(9, 9-bis(3′-(( N, N -dimethyl)- N -ethylammonium)-propyl)-2, 7-fluorene)- alt -2, 7-fluorene)- alt -2, 7-(9, 9-dioctylfluorene)]dibromide). Methanol soaking of the active layers improves the exciton dissociation and charge carrier transport and collection in the devices. This work provides a simple approach for preparing highly efficient CIL-free organic solar cells, which can be beneficial for large-scale and commercial applications.