Bipolar p-TPAOXD and m-TPAOXD are both tetraphenylmethane- based isomeric compounds containing triphenylamine- substituted 1,3,4-oxadizaole moieties. Two are amorphous materials showing no melting or crystallization transition but only glass transition at 187 and 149 degree(s)C, respectively. Single-layer organic light-emitting devices based on p-TPAOXD or m-TPAOXD as active layer were fabricated via spin-casting method. With varied fabrication conditions (solvent, cathode material, and film thickness) devices with turn-on voltage as low as 4V, blue electroluminance with intensity of 1,700 cd/m², and photometric efficiency larger than 0.7 cd/A can be achieved for p-TPAOXD. The luminance and photometric efficiency of the device containing m-TPAOXD are low (always less than 100 cd/m² and 0.2 cd/A) as compared to those containing p- TPAOXD.

Date Published: 27 February 2002
PDF: 8 pages
Proc. SPIE 4464, Organic Light-Emitting Materials and Devices V, (27 February 2002); doi: 10.1117/12.457488

Published in SPIE Proceedings Vol. 4464:
Organic Light-Emitting Materials and Devices V
Zakya H. Kafafi, Editor(s)