Fluorinated solid additives enable high efficiency non-fullerene organic solar cells

Abstract

Fluorinated solid additives have been designed to increase the π–π stacking of non-fullerene acceptor BTP-4F, leading to increased efficiency from 15.2% to 16.5% of PBDB-T-2F:BTP-4F binary solar cells with excellent stability.

A Review of Grazing Incidence Small‐ and Wide‐Angle X‐Ray Scattering Techniques for Exploring the Film Morphology of Organic Solar Cells

“…Recently, Wang and coworkers used three volatilizable organic solid additives, namely INB‐1F (2‐(4‐fluorobenzylidene)‐1H‐indene‐1,3(2H)‐dione), INB‐3F (2‐(2,4,6‐trifluorobenzylidene)‐1H‐indene‐1,3(2H)‐dione), and INB‐5F (2‐((perfluorophenyl)methylene)‐1H‐indene‐1,3(2H)‐dione) for PBDB‐T‐2F: 2,2'‐((2Z,2'Z)‐((12,13‐bis(2‐ethylhexyl)‐3,9‐diundecyl‐12,13‐dihydro‐[1,2,5]thiadiazolo[3,4‐e]thieno[2″,3″:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2‐g]thieno[2′,3′:4,5]thieno[3,2‐b]indole‐2,10‐diyl)bis(methanylylidene))bis(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐indene‐2,1‐diylidene))dimalononitrile (BTP‐4F) blend. [ 68 ] These additives evaporated upon moderate TA and exhibited higher volatility as the number of fluorine atoms increase. Results indicate that these additives enhanced the efficiency from 15.2% to 16.5%.…”

Ink Engineering of Transport Layers for 9.5% Efficient All‐Printed Semitransparent Nonfullerene Solar Cells

“…[ 15 ] Others have made use of volatile solid additives to avoid retention in the films and problems with long term device stability. [ 16,17 ] These strategies have resulted in solar cells with over 5% efficiency in areas larger than 5 cm 2 , however they are still limited in terms of geometry and ease of customization.…”

A History and Perspective of Non‐Fullerene Electron Acceptors for Organic Solar Cells

“…[96] Various volatilizable solid additives have been created and demonstrated to be able to promote the stacking of IT-4F and Y6 molecules. [97,98] It is clear that we are really only beginning to understand how chemical modification and process engineering can be used to tune NFA and blend morphology to deliver enhanced performance (including stability) in the highest efficiency systems. The most advanced structural-analytical techniques, together with lessons learned from the understanding of donor polymer phase morphology in fullerene systems will undoubtedly allow rapid advancements in both small molecule and polymeric NFAs in this regard.…”

“…[ 96 ] Various volatilizable solid additives have been created and demonstrated to be able to promote the stacking of IT‐4F and Y6 molecules. [ 97,98 ]…”