Combining carbazole electron donors with a high triplet energy and a pyridine electron acceptor with a high electron affinity, 2,6-bis(3-(carbazol-9-yl)phenyl)pyridine (26DCzPPy) is one of the most popular bipolar host materials used in organic light-emitting diodes.
Bipolar host materials are the molecules composed of an electron-donating moiety capable of mediating hole injection and transportation and an electron-withdrawing moiety capable of mediating electron injection and transportation.
*For chemical structure information please refer to the cited references.
Literature and Reviews
Blue and white phosphorescent organic light emittingdiode performance improvementbyconfining electrons and holes inside double emitting layers, Y-S.Tsai et al., J. Luminescence 153, 312–316 (2014); http://dx.doi.org/10.1016/j.jlumin.2014.03.040.
Soluble processed low-voltage and high efficiency blue phosphorescent organic light-emitting devices using small molecule host systems, Y. Doh et al., Org. Electronics, 13, 586–592 (2012); doi:10.1016/j.orgel.2012.01.003.
Color stable and low driving voltage white organic light-emitting diodes with low efficiency roll-off achieved by selective hole transport buffer layers, Z. Zhang et al., Org. Electronics 13, 2296–2300 (2012); http://dx.doi.org/10.1016/j.orgel.2012.07.001.
High performance top-emitting and transparent white organic light-emitting diodes based on Al/Cu/TcTa transparent electrodes for active matrix displays and lighting applications, Z. Zhang et al., Org. Electronics,14, 1452–1457 (2013); http://dx.doi.org/10.1016/j.orgel.2013.03.007.
Extremely stable-color flexible white organic lightemitting diodes with efficiency exceeding 100 lmW-1, B. Liu et al., J. Mater. Chem. C, 2, 9836 (2014); DOI: 10.1039/c4tc01582g.
Low-Driving-Voltage Blue Phosphorescent Organic Light-Emitting Devices with External Quantum Efficiency of 30%, K. Udagawa et al., Adv. Mater., 26, 5062–5066 (2014); DOI: 10.1002/adma.201401621.
Interface and thickness tuning for blade coated small-molecule organic light-emitting diodes with high power efficiency, Y-F. Chang et al., Appl. Phys. Lett.,114, 123101 (2013); doi: 10.1063/1.4821881.
Efficient red organic electroluminescent devices by doping platinum(II) Schiff base emitter into two host materials with stepwise energy levels, L. Zhou et al., Opt. Lett., 38 (14), 2373-2375 (2013); http://dx.doi.org/10.1364/OL.38.002373.