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Y6, BTP-4F

CAS Number 2304444-49-1

Materials, Non-Fullerene Acceptors

Product Code M2200A1-50mg
Price £210 ex. VAT

Y6 (BTP-4F) non-fullerene acceptor molecule for OPVs

Featured in Advance Science, Ossila Y6 solution processed thin-film transistors gained electron mobilities up to 2.4 cm2 V−1 s−1

Specifications | Pricing and Options | MSDS | Literature and Reviews

Y6 (CAS number 2304444-49-1) is a popular non-fullerene acceptor (NFA) molecule. The discovery of ITIC and the subsequent boom in the use of NFAs in organic photovoltaic solar cells (OPVs) has led to rapid improvements in device power conversion efficiencies (PCEs). The development of new NFA molecules like Y6 has continued this exciting trend. Using Y6 within a inert environment (such as a glove box), considerable jumps in solar cell performance have been achieved.

Also known BTP-4F, Y6 is a highly conjugated electron deficient organic semiconductor with an A-DAD-A structure. The Y6 molecule is composed of a fused thienothienopyrrolo-thienothienoindole (TTP-TTI) core base and 2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (2FIC) end units. These 2FIC end units are believed to promote intermolecular interactions and enhance optical absorption; the absorption spectrum of Y6 has a maximum at around 810 nm and extends to 1100 nm. This means that Y6 and its polymer blends have the potential to absorb light across the entire visible and near infra-red spectrum.

More soluble version of Y6 including Y6-BO and DTY6 bearing larger side chains to the nitrogen atoms in the bay area of the structures are also available at Ossila.

The benzothiadiazole core of Y6 allows for the creation of solar cells using the polymer PBDB-T-2F (PM6) as an electron donor. Impressive power conversion efficiencies of up to 15.7% have been demonstrated in optimised single-junction solar cells with both conventional and inverted architectures using Y6 and PM6.

High efficient non-flullerene acceptor

Highly Efficient NFA

With highly conjugated core

Wide optical absorption spectrum

Wide Optical Absorption Spectrum

Induced by intermolecular interactions

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High purity

High Purity

>98% high purity

Device structure: ITO/PEDOT:PSS/PM6:Y6/PDINO/Al.

Thickness (nm) VOC (V) JSC (mA cm-2) FF (%) PCE (%)
150 0.86 25.3 74.8 15.7

We supply high purity Y6 to institutions around the world. Quantities from 50 mg to 5 g are available to buy online (please contact us for larger orders) and eligible orders ship free.

Y6 (BTP-4F) from Ossila was used in the high-impact paper (IF 29.37), Triplet-Charge Annihilation in a Small Molecule Donor: Acceptor Blend as a Major Loss Mechanism in Organic Photovoltaics, J. Marin-Beloqui et al., Adv. Energy Mater., 2100539 (2021); DOI: 10.1002/aenm.202100539. Y6 Organic Thin-Film Transistors with Electron Mobilities of 2.4 cm2 V−1 s−1 via Microstructural Tuning, E. Gutierrez-Fernandez et al., Adv. Sci., 9 (1), 2104977 (2022); DOI: 10.1002/advs.202104977.

General Information

CAS Number 2304444-49-1
Chemical Formula C82H86F4N8O2S5
Purity >98% (1H NMR)
Full Name 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
Molecular Weight 1451.93 g/mol
HOMO / LUMO HOMO = -5.65 eV, LUMO = -4.10 eV [1]
Synonyms TTPTTI-4F, BTPTT-4F, BTP-4F, Y6F, BTP-4F-8
Classification / Family NFAs, n-type non-fullerene electron acceptors, organic semiconducting materials, low band-gap small molecule, small molecular acceptor, organic photovoltaics, polymer solar cells, NF-PSCs

Characterisation (1H NMR)

1H NMR of Y6-BTP-4F in CDCl3
1H-NMR spectrum of Y6 (BTP-4F) in CDCl3

Chemical Structure

Y6 non-fullerene acceptor structure
Chemical structure of Y6 (BTP-4F)

Y6 vs Y7 for OPVs

The success of the electron-deficient-core-based fused ring design of Y6 has led to the development of other non-fullerene acceptors for solar cells based on the same principle. One such molecule is the chlorinated form of BTP-4F, known as Y7 or BTP-4Cl. Using polymer donor PM6, devices created using BTP-4Cl have achieved a record PCE of 16.5%. This compares to 15.7% with Y6.

The absorption of Y7 is 20 nm redshifted compared to Y6 and its LUMO energy level is 100 meV lower.


Batch Quantity Price
M2200A1 50 mg £210
M2200A1 100 mg £370
M2200A1 250 mg £740
M2200A1 500 mg £1250
M2200A1 1 g £2100
M2200A1 5 g* £9500

* Available with a lead time of 4-5 weeks

MSDS Documentation

Y6 (BTP-4F) MSDSY6 (BTP-4F) MSDS Sheet

Literature and Reviews

  1. Single-Junction Organic Solar Cell with over 15% Efficiency Using Fused-Ring Acceptor with Electron-Deficient Core, J. Yuan et al., Joule (2019); doi: 10.1016/j.joule.2019.01.004.
  2. Fluorination vs. chlorination: a case study on high performance organic photovoltaic materials, Y. Zhang et al., Sci. China. Chem., 61 (10), 1328-1337 (2018); doi:10.1007/s11426-018-9260-2.
  3. Achieving over 16% efficiency for single-junction organic solar cells, B. Fan et al., Sci. China Chem., 62, 6 746-752 (2019); doi: 10.1007/s11426-019-9457-5.
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