Presently, flexible light sources mainly use organic materials integrated on lightweight and flexible plastic substrates. However, organic LEDs present a much lower luminance and a shorter lifetime in comparison to the LEDs based on inorganic nitride semiconductors. The inorganic semiconductor devices in their bulk form are mechanically rigid. Polymer-embedded nanowires (NWs) offer an elegant solution to create flexible optoelectronic devices, which combine the high efficiency and the long lifetime of inorganic semiconductor materials with the high flexibility of polymers.
In our recent work we have fabricated NW light emitters, which can sustain large deformations. NW arrays embedded in a flexible film and lifted-off from their native substrate were contacted with a silver NW mesh. The lift-off and transfer procedure enables the assembly of free-standing layers of NW materials with different bandgaps without any constraint related to lattice-matching or growth conditions compatibility .
This concept therefore allows for a large design freedom and modularity since it enables combination of materials with very different physical and chemical properties, which cannot be achieved by monolithic growth. NW membranes with different properties were assembled in a two-color LED . Combined with nano-phosphors, white flexible LEDs were demonstrated .
Flexible Light Emitting Diodes Based on Vertical Nitride Nanowires,
Xing Dai, Agnès Messanvi, Hezhi Zhang, Christophe Durand, Joël Eymery, Catherine Bougerol, François H. Julien, and Maria Tchernycheva
Nano Letter (2015) / DOI: https://doi.org/10.1021/acs.nanolett.5b02900
Flexible White Light Emitting Diodes Based on Nitride Nanowires and Nanophosphors,
N. Guan, X. Dai, A. Messanvi, H. Zhang, J. Yan, E. Gautier, C. Bougerol, F. Julien, C. Durand, J. Eymery & M. Tchernycheva
ACS Photonics (2016) / DOI: https://doi.org/10.1021/acsphotonics.5b00696
- Maria Tchernycheva, chargée de recherche CNRS au C2N (CNRS/UPSud)
Figure: © C2N / X. Dai