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Product Code M691-1g
Price £310 ex. VAT

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Bepp2, blue fluorescence emitter with excellent charge transport ability

ETL and HBL material used in high efficiency OLEDs


Bis[2-(2-hydroxyphenyl)-pyridine] beryllium, known as Bepp2, belonging to the beryllium complex family, is a blue fluorescence emitter with excellent charge transport ability. Due to its high electron mobility and high triplet energy level, Bepp2 has been used as an electron-transporting and hole/exciton-blocking layer material in OLEDs. High-efficiency blue OLEDs by using Bepp2 as the emitting layer material and high efficiency white OLEDs using Bepp2 as host material have been achieved [1-8].

Bepp2 can be also used as host material to fabricate orange, green, red EL devices.

General Information

CAS number 220694-90-6
Chemical formula C22H16BeN2O2
Molecular weight 349.39 g/mol
Absorption λmax 329 nm, 361 nm (chloroform)
Fluorescence λem 440 nm (chlorofom); 450 nm (film)
HOMO/LUMO HOMO = 5.7 eV, LUMO = 2.6 eV [1]
Synonyms
  • Be(pp)2Beryllium
  • bis[2-(2-pyridinyl)phenolate]Bis[2-(2-hydroxyphenyl)pyridinato]berylliumBis[2-(2-hydroxyphenyl)-pyridine]berylliumBis[2-(2-pyridinyl)phenolato]beryllium(II)
Classification / Family Blue emitter, Fluorescence host materials, Electron-transport layer (ETL), Hole-blocking layer (HBL), Sublimed materials

* Measurable with an optical spectrometer, see our spectrometer application notes.

Product Details

Purity Sublimed* > 99%
Melting point

TGA 365 °C (5% weight loss)

DSC 314 °C (onset)

Colour Light yellow powder/crystals

* Sublimation is a technique used to obtain ultra pure-grade chemicals, see sublimed materials.

Chemical Structure

Chemical structure of Bis[2-(2-hydroxyphenyl)pyridinato]beryllium
Chemical structure of Bis[2-(2-hydroxyphenyl)pyridinato]beryllium (Bepp2)

Device Structure(s)

Device structure ITO/NPB (60 nm)/Bepp2 (50 nm)/LiF (1 nm)/Al (200 nm) [1]
Colour Blue blue light emitting device
Max. Luminance 15, 000 cd/m2
Max. Current Efficiency 3.8 cd/A
Max. Power Efficiency 3.43 lm W−1
Device structure ITO/Cu-Pc(10 nm)/TPD(50 nm)/Bepp2 (40 nm)/LiF(1.5 nm)/Al(200 nm) [2]
Colour Blue blue light emitting device
Max. Luminance 4,000 cd/m2
Max. Power Efficiency 0.55 lm W−1
Device structure ITO/NPB (30 nm)/(bzq)2Ir(dipba):Bepp2 (20 nm)/Bepp2 (35 nm)/LiF (0.5 nm)/Al [3]
Colour White white light emitting device
Max. EQE 27.8%
Max. Current Efficiency 60.8 cd/A
Max. Power Efficiency 48.8 lm W−1
Device structure ITO/TPD (50 nm)/BePP2 (5 nm)/TPD (4 nm)/BePP2:rubrene (5 nm)/TPD (4 nm)/Alq (10 nm)/Al [4]
Colour White white light emitting device
Max. Luminance 20,000 cd/m2
Max. Power Efficiency 1.11 lm W−1
Device structure ITO/NPB (40 nm)/TCTA:Ir(ppy)3 (15 nm), 12 wt%/Bepp2:Ir(ppy)3 (15 nm), 12 wt%/LiF (1 nm)/Al  (100 nm) [6]
Colour Green green light emitting device
Max. EQE 18.6%
Max. Current Efficiency 58.7 cd/A
Max. Power Efficiency 65.1 lm W−1
Device structure ITO/DNTPD (40 nm)/Bepp2:Ir(ppy)3 (50 nm), 15 wt%/LiF (0.5 nm)/Al (100 nm) [7]
Colour Green green light emitting device
Max. Current Efficiency 38.3 cd/A
Max. Power Efficiency 46.4 lm W−1

MSDS Documentation

Bepp2 MSDSBepp2 MSDS sheet

Literature and Reviews

  1. High-performance blue electroluminescent devices based on hydroxyphenyl-pyridine beryllium complex, Y Liu, et al., Appl. Phys. Lett., 78, 2300 (2001); doi: 10.1063/1.1366338.
  2. Hydroxyphenyl-pyridine Beryllium Complex (Bepp2) as a Blue Electroluminescent Material, Y. Li et al., Chem. Mater., 12, 2672–2675 (2000); DOI: 10.1021/cm000237u.
  3. Highly efficient white organic electroluminescence device based on a phosphorescent orange material doped in a blue host emitter, T. Peng et al., J. Mater. Chem., 21, 3551-3553 (2011); DOI: 10.1039/C0JM03645E.
  4. Organic white light electroluminescent devices, S. Liu et al., Thin Solid Films, 363, 294-297 (2000); doi:10.1016/S0040-6090(99)01017-2. 
  5. White light emission induced by confinement in organic multiheterostructures, Z. Y. Xie et al., Appl. Phys. Lett., 74, 641 (1999); http://dx.doi.org/10.1063/1.123190.
  6. Low roll-off efficiency green phosphorescent organic light-emitting devices with simple double emissive layer structure, W-S. Jeon et al., Appl. Phys. Lett., 93, 063303 (2008); doi: 10.1063/1.2969040.
  7. Highly efficient bilayer green phosphorescent organic light emitting devices, W-S. Jeon et al., Appl. Phys. Lett., 92, 113311 (2008); http://dx.doi.org/10.1063/1.2898527.
  8. High-efficiency and high-quality white organic light-emitting diode employing fluorescent emitters, Y. Yang et al., Org. Electronics, 12 (1), 29-33 (2011); doi:10.1016/j.orgel.2010.10.006.
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