Journal Pre-proof Molecular designing of naphthalene diimide based fullerene-free small organic solar cell - Acceptors with high photovoltaic performance by density functional theory Usman Ali, Ayesha Javed, Hina Ramzan, Muhammad Shoaib, Ali Raza, Muhammad Tahir Khalil, Shi-Bo Cheng, Javed Iqbal PII: S1386-1425(19)31075-3 DOI: https://doi.org/10.1016/j.saa.2019.117685 Reference: SAA 117685 To appear in: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy Received Date: 17 August 2019 Revised Date: 6 October 2019 Accepted Date: 19 October 2019 Please cite this article as: U. Ali, A. Javed, H. Ramzan, M. Shoaib, A. Raza, M.T. Khalil, S.-B. Cheng, J. Iqbal, Molecular designing of naphthalene diimide based fullerene-free small organic solar cell - Acceptors with high photovoltaic performance by density functional theory, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy (2019), doi: https://doi.org/10.1016/j.saa.2019.117685. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier B.V.