Alternative selection of processing additives to enhance the lifetime of OPVs. (27th January 2016)

• Record Type: Journal Article
• Authors: Kettle, J; Waters, H; Horie, M; Smith, G C
• Is Part Of: Journal of physics. Volume 49:Number 8(2016)
• Publication Date: 2016-01-27
• Subjects: organic photovoltaics -- solar cells -- degradation -- XPS; Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/49/8/085601
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: The use of processing additives is known to accelerate the degradation of organic photovoltaics (OPVs) and therefore, this paper studies the impact of selecting alternative processing additives for PCPDTBT:PC71 BM solar cells in order to improve the stability. The use of naphthalene-based processing additives has been undertaken, which is shown to reduce the initial power conversion efficiency by 23%–42%, primarily due to a decrease in the short-circuit current density, but also fill factor. However, the stability is greatly enhanced by using such additives, with the long term stability ( T 50% ) enhanced by a factor of four. The results show that there is a trade-off between initial performance and stability to consider when selecting the initial process additives. XPS studies have provided some insight into the decreased degradation and show that using 1-chloronaphthalene (ClN) leads to reduced morphology changes and reduced oxidation of the thiophene-ring within the PCPDTBT backbone.