Solution‐Processed Organic Solar Cells Using New Electron Acceptor Derived from Naphthalene and Fluorene Unit. Issue 26 (12th September 2017)

• Record Type: Journal Article
• Authors: Nagarjuna, Puvvala; Chaturvedi, Neha; Bagui, Anirban; Runjhun, Rashmi; Garg, Ashish; Singh, Surya Prakash
• Is Part Of: ChemistrySelect. Volume 2:Issue 26(2017)
• Page Start: 7913
• Page End: 7917
• Publication Date: 2017-09-12
• Subjects: broad absorption -- high open circuit voltage -- modified fullerene acceptor -- organic solar cells -- PTB7; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201700910
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: We have developed two new electron acceptorsNAP‐C60 andN4 derived from naphthalene and fluorene, respectively for solution processed organic solar cells. In the case ofNAP‐C60, [6, 6]‐phenyl C61 ‐butyric acid methyl ester (PC61 BM) basic structure is modified by replacing its phenyl group with naphthalene group; while in the case ofN4, diaryl fullerene structure was modified using fluorene group. The UV‐visible spectra of the molecules show strong absorption in the UV region. Cyclic‐voltammetry measurements yielded the highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels ofN4 andNAP‐C60 molecules as (‐5.63 eV, −3.69 eV) and (5.80 eV, −3.70 eV), respectively. The best solar cell devices made from PTB7:NAP‐C60 and PTB7:N4 bulk composite films resulted in power conversion efficiencies of 4.1 and 4.3 %, respectively. The diarylmethanofullerene derivativeN4 shows a higher open circuit voltage compared to the methanofullerene derivativeNAP‐C60, attributed to low lying LUMO levels ofN4 . Abstract : New electron acceptors: Two fullerene acceptors NAP‐C60 and N4 have been developed from naphthalene and fluorene, respectively for OPV application with excellent absorption and electro‐chemical properties. It is shown that up‐shifted LUMO energy level results in high Voc in BHJ solar cells. The best solar cell made from PTB7:NAP‐C60 and PTB7:N4 blends exhibited a PCE of 4.1 and 4.3 %, respectively.