Benzoselenadiazole‐core asymmetric D‐A‐A small molecule for solution processed bulk heterojunction organic solar cells. (16th August 2020)

• Record Type: Journal Article
• Authors: Abdullah, ; Kim, Eun‐Bi; Akhtar, M. Shaheer; Shin, Hyung‐Shik; Ameen, Sadia
• Is Part Of: International journal of energy research. Volume 44:Number 14(2020)
• Page Start: 12100
• Page End: 12111
• Publication Date: 2020-08-16
• Subjects: benzoselenadiazole derivatives -- bulk heterojunction -- donor materials -- organic solar cells -- thin film; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.5658
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: The present work is accounted on the designing of a new and efficient asymmetric organic chromophore, named 4‐(3, 5‐bis [trifluoromethyl] phenyl)‐7‐(5′‐hexyl‐[2, 2′‐bithiophen]‐5‐yl)‐benzo[c [1, 2, 5]selenadiazole, (RT‐BSe‐F), based on benzoselenadiazole central acceptor building blocks. The acceptor unit of 3, 5‐bis (trifluoromethyl) benzene and donor unit of alkyl bithiophene attached with benzoselenadiazole central unit showed large impacts on the optical and electrochemical properties. The reasonable optical band gap of ~2.02 eV and HOMO of −5.33 eV were obtained by RT‐BSe‐F chromophore due to a strong electron accepting nature of fluorine based compound. With 3, 5‐bis(trifluoromethyl) benzene unit, the absorption of RT‐BSe‐F chromophore was considerably increased to higher wavelength which might enhance the crystallinity of thin film with high hole mobility. RT‐BSe‐F chromophore was effectively applied to fabricate the solution‐processed bulk‐heterojunction organic solar cells (BHJ‐OSCs) and attained a high power conversion efficiency (PCE) of ~3.75% accompanying high J SC of ~12.56 mA cm −2, FF of ~0.42 and V OC of ~0.71 V. The obtained high PCE might be associated to a high surface energy of TiO2 layer as buffer and the use of high mobility organic RT‐BSe‐F chromophore. Abstract : A new and efficient asymmetric organic chromophore based on benzoselenadiazole central unit (RT‐BSe‐F) is designed for bulk heterojunction organic solar cells. The acceptor unit of 3, 5‐Bis (trifluoromethyl) benzene and donor unit of alkyl bithiophene with benzoselenadiazole central unit shows good optical and electrochemical properties. A reasonable power conversion efficiency (PCE) of ˜3.75% with high Jsc of ˜12.56 mA/cm 2, are recorded for BHJ‐OSCs fabricated with RT‐BSe‐F:PC71BM active layer.