4,4"-Bis(9-carbazolyl)-2,2"-dimethylbiphenyl (CDBP) has a large bandgap (E = 3.4 eV) and a high triplet energy level (T₁ = 3.0 eV). It is used as a fluorescent and phosphorescent host material in blue, green, red and white OLED and TADF devices.

The high triplet energy level of CDBP is caused by the steric twisting from the methyl groups (in the 2 and 2′ position) of the biphenyl core. Compared to CBP and mCBP, CDBP has higher tendency to form excimers due to the localisation of the of the excitation onto the both ends of the carbazole units.

CDBP can also function as an exciton-blocking layer - it can block excitons migrating from the emitting layer into the hole-transport layer.

General Information

CAS number	120260-01-7
Full name	4,4"-Bis(9-carbazolyl)-2,2"-dimethylbiphenyl
Chemical formula	C38H28N2
Molecular weight	512.64 g/mol
Absorption	λmax 292 nm in THF
Fluorescence	λmax 364 nm in THF
HOMO/LUMO	HOMO = 6.1 eV, LUMO = 2.7 eV [1]
Synonyms	9-[4-(4-Carbazol-9-yl-2-methylphenyl)-3-methylphenyl]carbazole, 9,9"-(2,2"-Dimethylbiphenyl-4,4"-diyl)bis(9H-carbazole)
Classification / Family	Carbazole derivative, Fluorescent host materials, Phosphorescent host materials, Hole-transport layer materials, Exciton-blocking layer materials, TADF-OLED materials, Organic electronics, Sublimed materials.

Product Details

Purity	Sublimed > 99% (HPLC)
Melting point	Tg = 94 °C (lit.)
Appearance	White crystals/powder

Chemical Structure

Device Structure(s)

Device structure	ITO (50 nm)/TAPC (70 nm)/CDBP (10 nm)/6 wt% CCX-II*:PPF (20 nm)/PPF (10 nm)/BmPyPhB (30 nm)/Liq (1 nm)/Al (80 nm) [1]
Colour	Blue
Max. Power Efficiency	35.9 lm W−1
Max. Current Efficiency	41.1 cd/A
Max. EQE	25.9%

Device structure	ITO/NPB (60 nm)/4% 1*:CDBP (20 nm)/TAZ (40 nm)/LiF (1 nm)/Al (100 nm) [2]
Colour	Green
Power Efficiency@100 cd/m2	36.6 lm W−1
Current Efficiency@100 cd/m2	63.0 cd/A
EQE@100 cd/m2	16.3%

Device structure	ITO/NPB (40 nm)/6% Ir(btp)2(acac):CDBP (10 nm)/4% 1*:CDBP (4 nm)/12% FIrPic:CDBP (5 nm)/TAZ (40 nm)/LiF (1 nm)/Al (100 nm) [2]
Colour	White
Power Efficiency@100 cd/m2	18.5 lm W−1
Current Efficiency@100 cd/m2	34.2 cd/A
EQE@100 cd/m2	13.2%

Device structure	IITO/NPB (30 nm)/TcTa (5 nm)/CDBP:1* (20%, 8 nm)/CDBP (3 nm)/CDBP:BCzVBi (10%, 5 nm)/TPBi (40 nm)/LiF (1 nm)/Al (100 nm) [3]
Colour	White
Power Efficiency@100 cd/m2	16.9 lm W−1
Current Efficiency@100 cd/m2	29.1 cd/A
EQE@100 cd/m2	11.7%

Device structure	ITO (120 nm)/MoO3 (1 nm)/CDBP (35 nm)/20 wt% Ir(III) compound 3*:CDBP (15 nm)/TPBi (65 nm)/LiF (1 nm)/Al (100 nm) [4]
Colour	Blue
Max. Power Efficiency	23.9 lm W−1
Max. Current Efficiency	22.2 cd/A
Max. Luminance	4,269 cd/m2

Device structure	ITO/TAPC (40 nm)/CDBP (10 nm)/CDBP:PO-T2T (2:1):1 wt% AnbTPA* (14 nm)/CDBP:PO-T2T (3:1, 6 nm)/CDBP:PO-T2T(1.5:1):10 wt% 2CzPN (10 nm)/PO-T2T (45 nm)/LiF (1 nm)/Al (100 nm) [5]
Colour	White
Max. Power Efficiency	46.2 lm W−1
Max. Current Efficiency	36.8 cd/A
Max. EQE	19.2%

*For chemical structure information, please refer to the cited references

Pricing

Grade	Order Code	Quantity	Price
Sublimed (>99% purity)	M2188A1	250 mg	£187.00
Sublimed (>99% purity)	M2188A1	500 mg	£299.00
Sublimed (>99% purity)	M2188A1	1 g	£478.00

MSDS Documentation

CDBP MSDS sheet

Literature and Reviews

1. Blue organic light-emitting diodes realizing external quantum efficiency over 25% using thermally activated delayed fluorescence emitters, T. Miwa et al., Sci. Rep., 7, 284 (2017); DOI:10.1038/s41598-017-00368-5.
2. White Organic Light-Emitting Diodes with Evenly Separated Red, Green, and Blue Colors for Efficiency/Color-Rendition Trade-Off Optimization, S. Chen et al., Adv. Funct. Mater., 21, 3785–3793 (2011); DOI: 10.1002/adfm.201100895.
3. Platinum(II) cyclometallates featuring broad emission bands and their applications in colortunable OLEDs and high color-rendering WOLEDs, G. Tan et al., J. Mater. Chem. C, 4, 6016 (2016); DOI: 10.1039/c6tc01594h.
4. Highly efficient blue phosphorescent and electroluminescent Ir(III) compounds, Y. Kang et al., J. Mater. Chem. C, 1, 441 (2013); DOI: 10.1039/c2tc00270a.
5. Efficient, color-stable and high color-rendering-index white organic light-emitting diodes employing full thermally activated delayed fluorescence system, M. Zhang et al., Org. Electronics 50, 466e472 (2017); doi: 10.1016/j.orgel.2017.08.024.

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To the best of our knowledge the technical information provided here is accurate. However, Ossila assume no liability for the accuracy of this information. The values provided here are typical at the time of manufacture and may vary over time and from batch to batch.

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