New carbazole derivatives: Blue emitters and hole transport materials in OLEDs

ORGN 604

Pabitra K. Nayak, pabitra@tifr.res.in1, Neeraj Agarwal, nagarwal@tifr.res.in1, N Periasamy1, K. L. Narasimhan2, and Meghan P. Patankar3. (1) Department of Chemical Sciences, Tata Institute of Fundamental Research, Colaba, Homi Bhabha Road, Navy Nagar, Colaba, Mumbai, India, (2) Department of Condensed matter and Material Science, Tata Insitute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, India, (3) Department of Condensed matter and Material Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, India
In organic light emitting devices (OLEDs), one of the causes of device degradation is due to crystallization in the hole transport layer (HTL). A commonly used HTL is TPD which has a low Tg of about 65 șC. It is hence of interest to look for HTL materials with large Tg. A few fluorescent N-alkylcarbazole derivatives, which have high Tg were synthesized. The HOMO levels of these molecules are tuned and lie in the range of -5.5±0.2 eV, comparable to TPD (-5.4 eV). Thin films of nanometer thickness can be made out these compounds by spin-casting method. These molecules are shown to serve as HTL in a bilayer OLEDs with an advantage of having large value of Tg. Single layer devices based on these molecules exhibit blue electroluminescence. Exciplex based OLEDs are also demonstrated using some of these molecules.
 

Materials, Devices and Switches, Metal-Mediated Reactions, Asymmetric Reactions, Total Synthesis, Biologically-Related Molecules and Processes
7:00 PM-9:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- La Louisiane, Blrm. C, Poster

Division of Organic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008