An insight into the air stability of the benchmark polymer:fullerene photovoltaic films and devices: A comparative study
Document Type
Article
Publication Date
1-1-2020
Abstract
In this study, a comparative analysis of the instabilities and degradation routes of organic solar cell (OSCs) employing the three benchmarked donor polymers namely poly(3-hexylthiophene) (P3HT), polyN-900- heptadecany1-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10,30-benzothi adiazole)] (PCDTBT) and Poly4,8-bisl(2-ethylhexyl)oxyl benzo 1,2- b:4,5-b']dithiophene-2,6-diyl] 3-fluoro-2-(2 ethylhexyl)carbonyl] thieno thi-ophenediyl] (PTB7) along with 6,6]-phenylC(71) butyric acid methyl-ester (PC71BM) acceptor have been conducted using the extracted photovoltaic parameters in conjunction with the X-ray photoelectron spectroscopy (XPS), optical and morphological analysis. During the 14 days air stability test, the power conversion efficiency (PCE) decreased by 78.85%, 65.83% and 83.36% for P3HT:PC71BM, PCDTBT:PC71BM and PTB7:PC71BM based devices, respectively. However, the degradation study of the bulk heterojunction (BHJ) films was prolonged to 28 days in order to further elucidate the degradation factors affecting the device performance. XPS, optical and morphological studies enabled detailed information on the device degradation mechanisms and confirmed the oxidation of photoactive layer after ageing, morphological deterioration and fall in absorbance, particularly, the PTB7:PC71BM blend that showed the rapid degradation among all three. The results obtained in the current study advance the understanding of the stability/degradation mechanisms pertaining to the three most commonly used BHJ materials and hence, will help to improve the OSCs for longer lifetime.
Keywords
Organic photovoltaic, Photoactive polymers, Degradation, Stability
Divisions
PHYSICS
Funders
Solar Photovoltaic Academic Research Consortium II (SPARC II) project,Welsh European Funding Office,Engineering and Physical Sciences Research Council [Grant No: EP/N020863/1]
Publication Title
Organic Electronics
Volume
76
Publisher
Elsevier
Publisher Location
RADARWEG 29a, 1043 NX AMSTERDAM, NETHERLANDS