N-Annulated perylene diimide derivatives as non-fullerene acceptors for solution-processed solar cells with an open-circuit voltage of up to 1.14 V?

New Journal of Chemistry Pub Date: 2018-07-31 DOI: 10.1039/C8NJ02566E

Abstract

Three different non-fullerene small molecular acceptors containing N-annulated perylene diimide, named di-PNR, TPA-PNR and EDOT-PNR, were successfully designed and synthesized for photovoltaic applications. Introducing an electron donating unit such as triphenylamine (TPA) or 2,3-dihydrothieno[3,4-b][1,4]dioxine (EDOT) into the N-annulated PDI derivatives significantly influences the light-harvesting capabilities, energy level, morphology as well as the photovoltaic performance. Preliminarily, TPA-PNR and EDOT-PNR possessed lower band gaps and higher HOMO/LUMO energy levels. Power conversion efficiencies (PCEs) of 5.29% and 4.54% were obtained for the inverted solar cells based on the blends of PTB7-Th/di-PNR and PTB7-Th/TPA-PNR, respectively, resulting from the smooth morphology of the blend films and the intense light absorption that increases the Jsc and FF. Under the same optimization conditions, EDOT-PNR exhibited a low PCE of 1.6% with a remarkably high Voc of 1.14 V because of its higher LUMO energy level, which was one of the highest Voc values reported for organic solar cells using N-annulated PDI derivatives as electron acceptors. Our work offers effective guidelines for the design of non-fullerene acceptors using N-annulated PDI derivatives.

Graphical abstract: N-Annulated perylene diimide derivatives as non-fullerene acceptors for solution-processed solar cells with an open-circuit voltage of up to 1.14 V
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