Effect of Additives on the Performance of Non-Fullerene Based Organic Solar Cells in Non-Halogenated

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Mechanics, Materials Science & Engineering, July 2017 – ISSN 2412-5954

Effect of Additives on the Performance of Non-Fullerene Based Organic Solar Cells in Non-Halogenated Solvents1 L. Reshma1, V. Sai Saraswathi2, P. Induja3, M. Shivashankar4, K.Santhakumar1,a 1 – School of Electronics Engineering, VIT University, Vellore, Tamil Nadu, India 2 – School of Bio Science & Technology, VIT University, Vellore, Tamil Nadu, India 3 – School of Advanced Sciences, VIT University, Vellore, Tamil Nadu, India 4 – Carbon Dioxide and Green Technologies Centre, VIT University, Vellore, Tamil Nadu, India a – jhansiranidvr@gmail.com DOI 10.2412/mmse.69.45.881 provided by Seo4U.link

Keywords: polymer solar cell, non-fullerene acceptor, spray coating, power conversion efficiency, air stability.

ABSTRACT. Achieving highly stable and reliable organic solar cells relies on the advancement of good performance and enthusiastically reasonable hole transporting buffer layers tuned in to the anode and the photoactive materials of the solar cell stack. We explore the photophysics of all polymer solar cells based on the blends of the low band gap polymers poly(3-hexylthiophene) (P3HT) as a donor and poly {[N,N-9-bis(2-octyldodecyl)-naphthalene-1,4,5,8bis(dicarboximide)-2,6-diyl]-alt-5,59-(2,29-bithiophene)} (P(NDI2OD-T2)) as an acceptor blend active layer in 2-methyl anisole with 2% 1,8 diiodooctane (DIO) using air brush spray coating method. Polyethyleneimine ethoxylated (PEIE) is used as a surface modifier and SnO2 was used as an anode to minimize chemical damage of the transparent conducting electrode. The fabricated films were characterized and the solar cell performance was evaluated. An efficiency of 5.6 % was achieved and the devices are highly stable, retaining 75% of its original efficiency after being stored in air even without encapsulation.

Introduction. Solar cells are one of the best candidates to overcome traditional energy depletion and environmental pollution. Especially, organic solar cells (OSCs) represent an exciting class of renewable energy technology; they are lightweight, flexible and have a low production cost with a scalable approach for solar energy conversion [1]. Over the last two decades, the efficiency of these devices has improved significantly, in particular through the development of solution-processed bulk heterojunction (BHJ) OSCs [2,3] based on interpenetrating networks of polymer donors and acceptors that exhibit power conversion efficiencies (PCEs) over 10% mostly with fullerene-based electron acceptors [4]. Very recently, however, highly efficient solution-processable non-fullerene acceptors have been discovered and their performance is more or less comparable to that of conventional fullerene-based acceptors. The low-band-gap polymers of P3HT and P(NDI2OD-T2) were used as an electron-rich donor and as an electron-deficient acceptor respectively. 2-Methyl anisole, a halogen free greener organic solvent was selected as they are the most attractive processing solvents providing enough solubility and favourable morphology to improve the performance of P3HT: P(NDI2OD-T2) solar cell device and their environmental accumulation can also be significantly mitigated. In this paper, we report the effect of processing conditions on the performance of P3HT: P(NDI2OD-T2) based cells, and the nano-scale morphology of active layers using spraycoating technique [5] were 2-methyl anisole was used as the solvent [6,7]. The parameters such as spraying time and substrate-nozzle distance were varied and the coated active layers of P3HT: P(NDI2OD-T2) were investigated.

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© 2017 The Authors. Published by Magnolithe GmbH. This is an open access article under the CC BY-NC-ND license http://creativecommons.org/licenses/by-nc-nd/4.0/

MMSE Journal. Open Access www.mmse.xyz


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