Large‐Area Organic Solar Modules with Efficiency Over 14%

Abstract

It is still challenging to fabricate efficient large-area organic solar modules by solution processing. Processing window is important to obtain optimal aggregation of an active layer in large area for high efficiency. The star active layer of PM6:Y6 is processed from chloroform (for high efficiency) that has a narrow processing window due to the low boiling point of the solvent. In this work, the correlation between chemical structure (side chains) and processing solvents is investigated to obtain high efficiency and long processing windows. It is found that large side chains on the pyrrole ring are the key factor influencing the aggregation of active layer films. Short side chain (in Y6 and Y6-1O) will cause excess aggregation when processed from high-boiling-point solvent (chlorobenzene, CB), while long side-chain (in BTP-BO-4F, BTP-BO-4Cl, and BTP-eC9) can inhibit such aggregation and maintain high photovoltaic performance when processed from CB with wide processing window. In the end, over 25 cm 2 organic solar module via doctor blading based on PM6:BTP-eC9 active layer has been fabricated with a PCE of 14.07%.

In situandex situinvestigations on ternary strategy and co-solvent effects towards high-efficiency organic solar cells

“…, PM6 (poly[(2,6-(4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)benzo[1,2- b :4,5- b ′]dithiophene))- co -(1,3-di(5-thiophene-2-yl)-5,7-bis(2-ethylhexyl)-benzo[1,2- c :4,5- c ′]dithiophene-4,8-dione):eC11 (2,2′-((2 Z ,2′ Z )-((12,13-bis(2-butyloctyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-]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-dichloro-3-oxo-2,3-dihydro-1 H -indene-2,1-diylidene))dimalononitrile])) with ortho -xylene (XY) and 1-phenylnaphthalene (PN) and PM6:eC9 (2,2′-[[12,13-bis(2-butyloctyl)-12,13-dihydro-3,9-dinonylbisthieno[2′′,3′′:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2- e :2′,3′- g ][2,1,3]benzothiadiazole-2,10-diyl]bis[methylidyne(5,6-chloro-3-oxo-1 H -indene-2,1(3 H )-diylidene)]bis[propanedinitrile]]) with chlorobenzene (CB) and 1,8-diiodooctane (DIO). 46–48 Given that BN-T was proven to be effective in promoting the performance of the PM6:PY-IT system and PY-IT is a polymerized BTP-core based small molecule, we believed that they can also work with PM6:eC11 and PM6:eC9, presenting a new opportunity in the scientific understanding of these state-of-the-art efficiency OSC systems. 26 Consequently, the efficiency of the PM6:eC11:BN-T ternary devices increased from 17.15% to 18.10% in the binary counterpart, which is among the highest for OSCs processed by non-halogenated solvent(s) and non-halogenated solvent additive(s).…”

Producing p‐Doped Surface for Hole Transporting Layer‐Free Nonfullerene Organic Solar Cells

“…Surprisingly, the OMP-doping can only slightly enhance the performance of hole transporting layer-free OSCs from 0.1% to 2.1% (Figure S12, Supporting Information) based on the active layer of PBDB-T-2F:Y6:PC 71 BM, and from 0.6% to 4.6% based on the active layer of PBDB-T-2F:BTP-eC9:PC 71 BM (Figure S13, Supporting Information). Those efficiencies are still much lower than those references with MoO 3 [36] or PEDOT-based [37] hole transporting layer. The less effectiveness of OMP-doping method for the PBDB-T-2F:Y6:PC 71 BM and PBDB-T-2F:BTP-eC9:PC 71 BM are to be further investigated.…”

High‐Performance Organic Solar Modules via Bilayer‐Merged‐Annealing Assisted Blade Coating

“…[27] Films made by those methods can reserve almost full use of the materials from the coated solution, which is unlike spin coating discarded ≈90% of the material during solution spinning. [17,18] In recent years, research efforts, including active layer [23,25,28] and device architecture, [29] interface engineering, [30,31] and solvent processing, [32,33] have been reported to improve the performance of the blade or slot-die coated OSCs, wherein the various annealing treatments have been adapted to optimize the coated blend films due to the simplicities of methods. [34][35][36][37][38][39] Relying on those efforts, the performance of the coated OSCs and large-area modules has been encouragingly improved.…”