Bepp2

Order Code: M691
MSDS sheet

Price

(excluding Taxes)

£96.00


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)2
Beryllium bis[2-(2-pyridinyl)phenolate]
Bis[2-(2-hydroxyphenyl)pyridinato]beryllium
Bis[2-(2-hydroxyphenyl)-pyridine]beryllium
Bis[2-(2-pyridinyl)phenolato]beryllium(II)

Classification / Family Blue emitter, Fluorescence host materials, Electron-transport layer materials, Hole-blocking layer materials, Sublimed materials

 

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 to get rid of mainly trace metals and inorganic impurities. Sublimation happens under certain pressure for chemicals that only go through two physical stages from a solid sate to vapour (gas) and then the vapour condensed to a solid state on a cool surface (referred to as cold finger). The most typical examples of sublimation are iodine and dry ice. 

 

Chemical Structure

chemical structure of Bis[2-(2-hydroxyphenyl)pyridinato]beryllium, bepp2
Chemical structure of Bis[2-(2-hydroxyphenyl)pyridinato]beryllium (Bepp2); CAS No. 220694-90-6; Chemical formula C22H16BeN2O2.

 

Applications

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 energylevel, Bepp2 has been used as 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 used as host material to fabricate orange, green, red EL devices too.

 

Device structure                      ITO/NPB (60 nm)/Bepp2 (50 nm)/LiF (1 nm)/Al (200 nm) [1]
Colour Blue   blue
Max. Luminance 15, 000 cd/m2
Max. Current Efficiency                  3.8 cd/A
Max. Power Efficiency 3.43 lm W1
Device structure                      ITO/Cu-Pc(10 nm)/TPD(50 nm)/Bepp2 (40 nm)/LiF(1.5 nm)/Al(200 nm) [2]
Colour Blue   blue
Max. Luminance 4,000 cd/m2
Max. Power Efficiency 0.55 lm W1
Device structure ITO/NPB (30 nm)/(bzq)2Ir(dipba):Bepp2 (20 nm)/Bepp2 (35 nm)/LiF (0.5 nm)/Al [3]                      
Colour White   white
Max. EQE 27.8%
Max. Current Efficiency 60.8 cd/A
Max. Power Efficiency 48.8 lm W1
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
Max. Luminance 20,000 cd/m2
Max. Power Efficiency 1.11 lm W1
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
Max. EQE 18.6%
Max. Current Efficiency 58.7 cd/A
Max. Power Efficiency 65.1 lm W1
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
Max. Current Efficiency 38.3 cd/A
Max. Power Efficiency 46.4 lm W1
Device structure ITO/NPB (400 nm)/Bepp2:DCM (0.2 wt.%, 3 nm)/ Bepp2:DCM (0.5 wt.%, 42 nm)/LiF (1 nm)/Al [8]
Colour White   white
EQE@100 cd/m2 9.7-13.1%
Current Efficiency@100 cd/m2 23.8-32.2 cd/A
Power Efficiency@100 cd/m2 13.9-18.9 lm W1

 

Characterisations (DSC and TGA)

TGA-DSC trace of Bepp2, Bis[2-(2-hydroxyphenyl)-pyridine]beryllium
DSC-TGA traces of Bepp2.

 

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.