Expanding the application space of transparent electrodes toward the ultraviolet range has been found challenging when utilizing the conventional approach to degenerately dope semiconductors with band gaps larger than ZnO or In2O3. Here, it is shown that the correlated metal SrxNbO3 with x < 1 is ideally suited as a UV-transparent electrode material, enabling UV light-emitting diodes for a wide range of applications from water disinfection to polymer curing. It is demonstrated that SrxNbO3 thin films can be grown by radio frequency (RF) sputtering and that they remain in the perovskite phase despite a sizeable Sr deficiency. The electrical and optical properties are characterized and compared to those of commonly used indium tin oxide (ITO) and Sn-doped Ga2O3 transparent conductor standards. SrxNbO3 films were found to have sheet resistances as low as 30 ω sq-1 with optical transmission at a wavelength of 280 nm up to 86%, marking a two-order-of-magnitude increase over the performance of traditional UV-transparent conductors. The compatibility of SrxNbO3 with a physical vapor deposition technique that is widely employed in the transparent conductor coating industry along with the robustness of the highly electrically conducting and optically transparent perovskite phase makes it an ideal transparent electrode for applications in the UV spectrum.
Bibliographical noteFunding Information:
J.R., N.G., A.P., and R.E.-H. acknowledge support from the National Science Foundation through DMREF Grant No. DMR-1629477. A.P. and T.B. acknowledge support from the NSF through DMREF Grant No. DMR-1629260 for DFT calculations. K.A. and N.A. acknowledge the Penn State MRSEC Program DMR-1420620 for the TEM sample preparation and STEM experiments. This material is based upon work supported in part by the NSF Graduate Research Fellowship Program under Grant No. DGE1255832 (J.R.). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
Copyright © 2020 American Chemical Society.
- correlated metal
- thin film
- transparent conductor
PubMed: MeSH publication types
- Journal Article