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 |
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. For more details about sublimation, please refer to the Sublimed Materials for OLED devices page.
Chemical Structure
Device Structure(s)
Device structure | ITO/NPB (60 nm)/Bepp2 (50 nm)/LiF (1 nm)/Al (200 nm) [1] |
Colour | Blue |
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 |
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 |
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 |
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 |
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 |
Max. Current Efficiency | 38.3 cd/A |
Max. Power Efficiency | 46.4 lm W−1 |
MSDS Documentation
Bepp2 MSDS sheet
Literature and Reviews
- 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.
- Hydroxyphenyl-pyridine Beryllium Complex (Bepp2) as a Blue Electroluminescent Material, Y. Li et al., Chem. Mater., 12, 2672–2675 (2000); DOI: 10.1021/cm000237u.
- 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.
- Organic white light electroluminescent devices, S. Liu et al., Thin Solid Films, 363, 294-297 (2000); doi:10.1016/S0040-6090(99)01017-2.
- 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.
- 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.
- 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.
- 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.
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.