Abstract
We present a new colloidal synthesis of gallium-doped zinc oxide nanocrystals that are transparent in the visible and absorb in the near-infrared. Thermal decomposition of zinc stearate and gallium nitrate after hot injection of the precursors in a mixture of organic amines leads to nanocrystals with tunable properties according to gallium amount. Substitutional Ga3+ ions trigger a plasmonic resonance in the infrared region resulting from an increase in the free electrons concentration. These nanocrystals can be deposited by spin coating, drop casting, and spray coating resulting in homogeneous and high-quality thin films. The optical transmission of the Ga-ZnO nanoparticle assemblies in the visible is greater than 90%, and at the same time, the near-infrared absorption of the nanocrystals is maintained in the films as well. Several strategies to improve the films electrical and optical properties have been presented, such as UV treatments to remove the organic compounds responsible for the observed interparticle resistance and reducing atmosphere treatments on both colloidal solutions and thin films to increase the free carriers concentration, enhancing electrical conductivity and infrared absorption. The electrical resistance of the nanoparticle assemblies is about 30 kΩ/sq for the as-deposited, UV-exposed films, and it drops down to 300 Ω/sq after annealing in forming gas at 450 °C, comparable with state of the art tin-doped indium oxide coatings deposited from nanocrystal inks. © 2013 American Chemical Society.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3439-3448 |
| Number of pages | 10 |
| Journal | Journal of the American Chemical Society |
| Volume | 135 |
| Issue number | 9 |
| DOIs | |
| State | Published - Feb 21 2013 |
| Externally published | Yes |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledged KAUST grant number(s): KUS-C1-015-21
Acknowledgements: This work was done in the framework of collaborative research activities of Technical Committee 16 (on Nanostructured Glasses), of the International Commission on Glass (ICG). S.M., R.N., and A.S. kindly acknowledge support from the Global Climate energy Project at Stanford University. Partial support by the Center for Advanced Molecular Photovoltaics (award no. KUS-C1-015-21), made by King Abdullah University of Science and Technology (KAUST), is acknowledged as well. Diane Wu is acknowledged for TEM microscopy.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.