New small organic molecules based on thieno[2,3-b]indole for efficient bulk heterojunction organic solar cells: a computational study |
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Authors: | Mohamed Hachi Ahmed Slimi Asmae Fitri Souad ElKhattabi Adil Touimi Benjelloun Mohammed Benzakour |
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Affiliation: | 1. Faculty of Sciences Dhar el Mahraz, ECIM, LIMME, Sidi Mohamed Ben Abdallah University, Fez, Moroccomohamed.hachi@usmba.ac.mahachimohamed1990@gmail.comhttps://orcid.org/0000-0002-4656-7948;4. Faculty of Sciences Dhar el Mahraz, ECIM, LIMME, Sidi Mohamed Ben Abdallah University, Fez, Morocco;5. National School of Applied Sciences, LISA, Sidi Mohamed Ben Abdallah University, Fez, Morocco |
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Abstract: | ABSTRACTThis study aims to evaluate the characteristics of novel organic D-π-A-π-D class small-molecules by using carefully the density functional theory, and time-dependent density functional theory calculations. Thedesigned sequence of (D-A) BHJ-1a to BHJ-4a in organic Bulk Heterojunction (BHJ) solar cells has been comprehensively analysed. Thiéno[2,3-b]indole (TI) has been used as donor, and Diketopyrrolopyrrole (DPP) as acceptor for all compounds. In order to improve the electronic, photovoltaic, and opticalproperties, we have substituted thiophene unit with furan, thieno[2,3-b]thiophene, thiazole and thiazolothiazole as π-bridge moieties. Thus, the result shows that the wise choice of the π-bridge units plays a significant role in improving Egap, producing a high bathochromic shift, and increasing VOC as well as a theoretical power conversion efficiency (PCE) over 7%. Interestingly, BHJ-4a with suitable π-bridge presents the optimal electronic properties with low band gap (1.870?eV) and high VOC (1.534?eV). Furthermore, we have modelled a Bulk heterojunction organic photovoltaic cells based on donor-PCBM complex in order to achieve the optimum Egap and VOC. Consequently, the obtained results provide a new way to design BHJ small molecule donors with higher power conversion efficiency. |
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Keywords: | DFT PCBM thiéno[2,3-b]indole BHJ organic solar cells UV–Vis |
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