Tailor-made nanostructures bridging chaos and order for highly efficient white organic light-emitting diodes


Organic light-emitting diodes (OLEDs) suffer from notorious light trapping, resulting in only moderate external quantum efficiencies. Here, we report a facile, scalable, lithography-free method to generate controllable nanostructures with directional randomness and dimensional order, significantly boosting the efficiency of white OLEDs. Mechanical deformations form on the surface of poly(dimethylsiloxane) in response to compressive stress release, initialized by reactive ions etching with periodicity and depth distribution ranging from dozens of nanometers to micrometers. We demonstrate the possibility of independently tuning the average depth and the dominant periodicity. Integrating these nanostructures into a two-unit tandem white organic light-emitting diode, a maximum external quantum efficiency of 76.3% and a luminous efficacy of 95.7 lm W−1 are achieved with extracted substrate modes. The enhancement factor of 1.53 ± 0.12 at 10,000 cd m−2 is obtained. An optical model is built by considering the dipole orientation, emitting wavelength, and the dipole position on the sinusoidal nanotexture.

dimeticone, nanomaterial, silastic, efficiency measurement, electrode, vertical distribution, wavelength, Article, atomic force microscopy, chemical binding, electrochemical analysis, energy dispersive X ray spectroscopy, finite element analysis, flow rate, Fourier transformation, gas flow, impedance spectroscopy, irradiation, light intensity, mathematical model, measurement repeatability, molecular imprinting, nanofabrication, optical rotation, optics, pattern recognition, periodicity, photostimulation, reactive ion etching, refraction index, scanning electron microscopy, spectroscopy, stimulus, stress, X ray diffraction, X ray photoemission spectroscopy
Li, Y., Kovačič, M., Westphalen, J., Oswald, S., Ma, Z., Hänisch, C., et al. (2019). Tailor-made nanostructures bridging chaos and order for highly efficient white organic light-emitting diodes (Version publishedVersion, Vol. 10). Version publishedVersion, Vol. 10. London : Nature Publishing Group. https://doi.org//10.1038/s41467-019-11032-z