FREE shipping to on qualifying orders when you spend or more, processed by Ossila BV. All prices ex. VAT. Qualifying orders ship free worldwide! Fast, secure, and backed by the Ossila guarantee. It looks like you are visiting from , click to shop in or change country. Orders to the EU are processed by our EU subsidiary.

It looks like you are using an unsupported browser. You can still place orders by emailing us on, but you may experience issues browsing our website. Please consider upgrading to a modern browser for better security and an improved browsing experience.

Image missing
Product Code M2188A1-250mg
Price £240 ex. VAT

CDBP, host material in blue, green, red and white OLED and TADF devices

High-purity (>99.0%) and available online for priority dispatch

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

CDBP structure
Chemical Structure of CDBP

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 blue light emitting device
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 green light emitting device
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 white light emitting device
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 white light emitting device
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 blue light emitting device
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 white light emitting device
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


Grade Order Code Quantity Price
Sublimed (>99% purity) M2188A1 250 mg £240
Sublimed (>99% purity) M2188A1 500 mg £400
Sublimed (>99% purity) M2188A1 1 g £640

MSDS Documentation


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.
Return to the top