Bottom-up growth of fully transparent contact layers of indium tin oxide nanowires for light-emitting devices


Thin layers of indium tin oxide are widely used as transparent coatings and electrodes in solar energy cells1, flat-panel displays2,3, antireflection coatings4, radiation protection5 and lithium-ion battery materials6, because they have the characteristics of low resistivity, strong absorption at ultraviolet wavelengths, high transmission in the visible7, high reflectivity in the far-infrared and strong attenuation in the microwave region. However, there is often a trade-off between electrical conductivity and transparency at visible wavelengths for indium tin oxide and other transparent conducting oxides. Here, we report the growth of layers of indium tin oxide nanowires that show optimum electronic and photonic properties and demonstrate their use as fully transparent top contacts in the visible to near-infrared region for light-emitting devices.

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Figure 1: ITO nanowire nucleation and growth.
Figure 2: Electrical characterization of ITO nanowire/SiGe MQW contacts.
Figure 3: Optical transmission characteristics of ITO nanowire layers.
Figure 4: Photo- and electroluminescence emission from ITO nanowire-contacted SiGe MQW LED.


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The authors acknowledge support from Science Foundation Ireland (02/IN.1/172) and the EU Network of Excellence nanoPhotonics to Realise Molecular Scale Technologies (PhOREMOST) (FP6/2003/IST/2-511616). V.L. thanks the Programa Bicentenario de Cienca y Tecnología (PBCT), Chile (ACT027) and Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brazil. We also acknowledge the contributions of N. Roos and T. P. Sidiki to the design of the MBE reactor, and thank A. C. Martín (Consejo Superior de Investigaciones Cientificas, CSIC) for MBE deposition of Ti/Pt/Au bottom contacts on selected samples, and D. Lebedev (University of Wuppertal) for ellipsometric characterization. We also thank C. Gergely and P. Arcade (Université Montpellier II) for access to their far-infrared spectrometer.

Author information

C.O.D., M.S. and C.M.S.T. conceived and designed the experiments and analyses. C.O.D., M.S. and G.V. performed the experiments. C.O.D., M.S., G.V. and V.L. analysed the data. S.B.N. conducted part of the TEM analysis and C.M.S.T. supervised the work. All authors discussed the results and C.O.D. wrote the manuscript.

Correspondence to C. O'Dwyer or V. Lavayen.

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O'Dwyer, C., Szachowicz, M., Visimberga, G. et al. Bottom-up growth of fully transparent contact layers of indium tin oxide nanowires for light-emitting devices. Nature Nanotech 4, 239–244 (2009).

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