TPD has been dissolved in A435, a high Tg host polymer, in order to inhibit the crystallization of the hole transport molecule. Solid solutions of TPD have been obtained for a TPD content, x, ranging from 25 to 90 wt%. A435 + x TPD films coated onto ITO are stable during at least 72h at 150°C, for TPD contents of 50 wt% and below. OLEDs having the structure: ITO / A435 + x TPD/ Alq3 /Mg have been prepared and measured. Maximum luminances of about 2000 cd/m2 are obtained for x ≥ 50 wt% TPD. The maximum quantum yield of these devices is 1.4%.
F. Santerre, J.P. Dodelet, Y. Sun, A. R. Hlil, A. S. Hay, M. D'Iorio, "OLED Performance and the Use of a Hole Transport Molecule Dissolved in a High Tg Host Polymer" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP15), 1999, pp 747 - 750, https://doi.org/10.2352/ISSN.2169-4451.1999.15.1.art00095_2