F8BT (PFBT), CAS number 210347-52-7, a widely used green emitting reference polymer for a variety of applications including as an emissive species in OLEDs [1], an approximately balanced p-type and n-type polymer for OFETs [2] and light emitting transistors [3] as well as being used a polymeric accepter for OPVs [1]. The deep lying HOMO and LUMO levels (5.9 / 3.3 eV) makes it air stable while the liquid-crystalline and beta phases make it widely used for basic research purposes.

General Information

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Full name	Poly(9,9-dioctylfluorene-alt-benzothiadiazole)
Synonyms	F8BT, PFBT
Chemical formula	(C35H42N2S)n
CAS number	210347-52-7
HOMO / LUMO	HOMO = -5.9 eV, LUMO = -3.3 eV [2]
Classification / Family	Polyfluorenes, Benzothiodiazoles, Organic semiconducting materials, Semiconducting polymers, OLED green emitter materials, OLED materials, Organic Photovoltaic materials, Polymer solar cells, OFET materials

Product Details

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Purity	> 99.9%
Appearance	Orange powder/flakes

Chemical Structure

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Chemical structure of F8BT, CAS 210347-52-7

Device Structure(s)

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Device structure	ITO/PEDOT:PSS/TFB/F8BT/F8imBT-Br*/Ca/Al [4]
Colour	Green
Max. EQE	5.1%
Max. Current Efficiency	17.9 cd/A
Max. Power Efficiency	16.6 lm W−1

Usage Datasheet

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For a high efficiency green OLED we recommend blending F8 (PFO) with F8BT with the below specifications. This ink can then be deposited either in air or in a glove box with little difference in performance, provided that the exposure time and light levels are minimised. For more details see our fabrication guide.

At typical concentrations of 10 mg/ml 100 mg of F8 (PFO) will make around 200 spin-coated devices on Ossila's standard ITO substrates (20 x 15 mm) assuming 50% solution usage (50% loss in filtering and preparation).

OLED reference device:

• F8 with F8BT
• Blend ratio of 19:1 (F8:F8BT) in Toluene
• Total concentration of 10 mg/ml
• 0.45 μm PTFE (hydrophobic) filter
• Spun at 2000 rpm (approx. 70 nm thickness)

Pipetting 20 μl of the above solutions onto a substrate spinning at 2000 rpm should provide a good even coverage with approximately 70 nm thickness. The substrate needs to be spun until dry, which is typically only a few seconds — 15 seconds should be ample to achieve this. Thermal annealing should be undertaken at 80°C for 10 minutes prior to cathode deposition

A basic but efficient OLED can be made using PEDOT:PSS as a hole transport layer and Calcium/Aluminum as the electron contact. When used with the Ossila ITO substrates and shadow masks this produces an easy to fabricate yet efficient >100 cd/m2 device.

Typical Ossila device architecture: Polyfluorene-based OLED architecture based on F8 blended with F8BT.

Technical Data

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Product Code	Soluble solvents	Recommended Processing Solvents at 10mg/ml
M0231A4	Chloroform, chlorobenzene	Chlorobenzene
M0231A5	Toluene, chloroform, chlorobenzene	Toluene
M0231A6	Toluene, chloroform, chlorobenzene	Toluene
M0231A7	Toluene, chloroform, chlorobenzene	Toluene
M0231A8	Toluene, chloroform, chlorobenzene	Toluene