Skip to main content Accessibility help

New Transparent Substrate with Silica Aerogel Film for Surface-Emissive Devices

  • H. Yokogawa (a1), K. Kawano (a1), M. Yokoyama (a1), T. Tsutsui (a2), M. Yahiro (a2) and Y. Shigesato (a3)...


Silica aerogels prepared by sol-gel methods with supercritical drying process have transparency and extremely low refractive index which is not available in any other materials. This extraordinary refractivity is expected to present some new features as an optical material. Ordinarily, coupling-out efficiency of surface-emissive light sources has been assumed to be low. It is due to the losses organized from internal reflection of emitted light at the air-glass interface and dissipation during wave-guiding propagation within the substrate.

However, when material that has extremely low refractive index is inserted between a thin luminescence layer and glass substrate, almost all the light from the luminescence layer can efficiently couple out to air passing through the glass substrate. In this report, we introduce a silica aerogel film as a low refractive index material for surface-emissive devices, such as photoluminescent and electroluminescent device. In the experiments, the photoluminescence intensity of Alq3 through the silica aerogel layer was twice as large as that of the glass substrate without the silica aerogel film. Moreover, we formed a new substrate which contained a transparent electrode on the silica aerogel film. Using this substrate, we fabricated the OLED and observed the disappearance of wave-guiding propagation within the glass substrate.



Hide All
1. Tsutsui, T., MRS Bull. 22, 3945 (1997).
2. Gu, G., Garbuzov, D. Z., Burrows, P. E., Vankatsh, S., Forrest, S.R., and Thompson, M.E., Opt.Lett. 22, 396398 (1997).
3. Yamasaki, T., Sumioka, K., and Tsutsui, T., Appl. Phys. Lett. 76(10), 12431245 (2000).
4. Yokogawa, H. and Yokoyama, M., J. Noncryst. Solids 186, 2329 (1995).
5. Friend, R. H., Gymer, R. W., Holmes, A.B., Burroughes, J.H., Marks, R.N., Taliani, C., Bradley, D.D.C., Santos, D.A. Dos, Bredas, J.L., Logdlund, M., and Salaneck, W.R., Nature 397, 121128 (1999).
6. Tsutsui, T., Yang, M.J., Yahiro, M., Nakamura, K., Watanabe, T., Tsuji, T., Fukuda, Y., Wakimoto, T., and Miyaguchi, S., Jpn. J. Appl. Phys. 38 (12a), L1502–L1504 (1999).


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed