ITIC

ITIC represents the start of a new generation of non-fullerene electron-accepting small molecules for organic photovoltaics (OPVs). The energy levels of ITIC allow for good alignment with low band-gap polymers, resulting in enhanced charge separation efficiency and reduced energy loss. ITIC molecules also have strong and broad absorption characteristics, from the visible region of the electromagnetic spectrum to the near infrared, peaking at 700 nm. This gives it the potential to increase the total absorption of an OPV device and enable improved power conversion efficiencies (PCEs).

These properties have resulted in ITIC becoming the first small molecule electron acceptor to outperform the most efficient fullerene acceptor, PC₇₀BM, in an OPV device. When used in conjunction with PBDB-T (PCE12) in an inverted-architecture device, ITIC enabled a power conversion efficiency of over 11% to be reached. By comparison, when PC₇₀BM was used as the electron acceptor, a PCE of less than 8% was achieved.

ITIC has also proved to have excellent thermal stability, with devices showing no losses after being held at 100 °C for 250 hours.

ITIC 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.

ITIC represents an exciting new advancement for organic photovoltaics (OPVs). We supply ITIC itself and a range of other non-fullerene acceptors, including ITIC family members ITIC-2F, ITIC-DCl, ITIC-M, ITIC-Th, and ITIC-DM. Most quantities are available for priority dispatch (lead times may apply for large quantities) and qualifying orders ship free as part of the Ossila Guarantee. Please contact us if you have any questions.

Non-Fullerene Acceptors for OPVs

• Wide Range
• High Purities
• Low Prices

Available From £190

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Characterisation (¹H NMR)

Chemical Structure

What Makes ITIC a Good Electron Acceptor for OPVs?

Before the discovery of ITIC in 2015, fullerene acceptors were the most used and best performing electron acceptors for organic photovoltaics. However, there are some significant issues with fullerenes, primarily relating to their energy levels, absorption characteristics, and stability. Researchers have therefore been looking to replace fullerenes as the electron acceptors in OPV devices. Small molecule non-fullerene acceptors like ITIC are excellent candidates for this.

ITIC improves the performance of polymer solar cells via three main mechanisms. First, the absorption spectrum of ITIC is much more complementary to PBDB-T than that of PC₇₀BM, with significantly less overlap of the two spectra. This enables increased absorption for the device, particularly at the longer wavelengths (>650 nm) where the solar photon flux is high. Fullerenes generally have poor absorption in the range of the solar spectrum, with peak absorption towards ultraviolet where the photon flux is low.

Compared to PC₇₀BM, ITIC also offers an improvement of the energy level alignment of the materials. The molecular energy levels of ITIC are much closer to those of PBDB-T, which results in reduced energy loss during exciton dissociation and charge transfer. While the electron mobility of ITIC is lower than that of PC₇₀BM, this results in more balanced electron and hole transport within PBDB-T:ITIC devices, preventing a build-up of charge within the solar cell. In addition, it is difficult to tune the energy levels of fullerenes to align with donor polymers, which limits their potential efficiency within solar cells (due to energy loss from sub-optimal energy level alignment).

Showing excellent thermal stability, ITIC also addresses the instability issues caused by using fullerenes, which tend to crystallise over time, leading to reduced lifetimes for solar cells that use them. ITIC devices showed no performance loss after 250 hours at 100 °C. This is significantly better than that of devices using PC₇₀BM, which lost nearly 50% of their PCE under the same conditions. This is due to the tendency of PC₇₀BM to aggregate at high temperatures, causing phase separation and a loss of the efficient bulk heterojunction – a property which is not shared by ITIC.

ITIC Derivatives

The ITIC family includes ITIC itself and a number of derivatives, which may offer higher power conversion efficiencies than ITIC itself. We stock a selection of high purity ITIC derivatives for organic and polymer solar cells.

ITIC-4F

ITIC-4F, or ITIC-2F, has deeper HUMO/LUMOO energy levels than ITIC and an improved absorption coefficient. It pairs well with most polymer semiconductor donors, and can cover a broad absorption spectrum. An efficiency of over 13% has been achieved with ITIC-4F as the electron acceptor and PBDB-T-SF as the donor material.

Available from £190.

ITIC-DCl

Also known as ITIC-4Cl or IT-4Cl, ITIC-DCl has lower HUMO and LUMO energy levels than ITIC-2F and has been used to create high performance non-fullerene organic solar cells. With PBDB-T-F as a donor polymer material, a power conversion efficiency of over 14% has been achieved using ITIC-DCl as the electron acceptor.

Available from £190

ITIC-M

ITIC-M, or IT-M, is more electron rich than ITIC, and therefore has a higher LUMO energy level. It also has good solubility, making it well suited for use as a non-fullerene acceptor in high-efficiency polymer solar cells. An efficiency of more than 12% has been achieved using ITIC-M as the acceptor material.

Available from £190

ITIC-Th

ITIC-Th, or IT-Th, has lower HUMO and LUMO energy levels than ITIC. As a result, it has the potential to match the energy levels of a wide range of high performance polymer semiconductor donor materials for the creation of highly efficient non-fullerene polymer solar cells.

Available from £290

ITIC-DM

ITIC-DM has higher HUMO and LUMO energy levels than either ITIC or ITIC-M and is well suited for organic solar cells. It also has the potential to provide better solubility and film morphology than ITIC, which makes it an attractive candidate for device fabrication.

Available from £290

ITIC and its derivatives can absorb a large range of wavelengths for devices, making them ideal candidates for most polymer donor materials. In particular, they work well with medium-to-wide band-gap polymer semiconductors used in organic solar cells.

OPV Polymer Donors

• PBDD4T-2F, J71, PCE12 and More
• High Purity
• Low Price

Available From £210

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Literature and Reviews

1. Non-Fullerene Polymer Solar Cells Based on Alkylthio and Fluorine Substituted 2D-Conjugated Polymers Reach 9.5% Efficiency, H. Bin et al., J. Am. Chem. Soc.,138 (2016), 4657−4664; DOI: 10.1021/jacs.6b01744.
2. Fullerene-Free Polymer Solar Cells with over 11% Efficiency and Excellent Thermal Stability, W. Zhao et al., Adv. Mater., 28, 4734–4739 (2016); DOI: 10.1002/adma.201600281.
3. An Electron Acceptor Challenging Fullerenes for Efficient Polymer Solar Cells, Y. Lin et al., Adv. Mater., 27, 1170–1174 (2015); DOI: 10.1002/adma.201404317.
4. High-Efficiency Nonfullerene Polymer Solar Cells with Medium Bandgap Polymer Donor and Narrow Bandgap Organic Semiconductor Acceptor, L. Gao et al., Adv. Mater., 28, 8288–8295 (2016); DOI: 10.1002/adma.201601595.