Sputtered Sr_xNbO₃ as a UV-Transparent Conducting Film

Abstract

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 Sr x NbO3 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 Sr x NbO3 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. Sr x NbO3 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 Sr x NbO3 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.

Highly Transparent and Conductive Indium‐Free Vanadates Crystallized at Reduced Temperature on Glass Using a 2D Transparent Nanosheet Seed Layer

“…These performances have to be compared to those of SrNbO 3 (SNO) thin film, recently identified as a new performing TCO perovskite in ultraviolet range. [55,56] For SNO, the transmittance efficiency reaches 73% and makes it a good candidate for PV applications. Overall, the FOM and transmittance efficiency of our vanadate films integrated on glass is in the same order of magnitude as standard TCOs, demonstrating their excellent perfomances and the sustainability of this new integrating process for the next generation of TCOs such as vanadates or SNO.…”

Design Principles for the Enhanced Transparency Range of Correlated Transparent Conductors

“…[ 7,8 ] Very recently, few studies on 4 d 1 SrNbO 3 also showed transparency in ultraviolet, but the investigation of infrared transmittance was missing. [ 13 − 15 ] Although diverse experimental findings have been reported in this rapidly expanding field, the availability of correlated metals with a wide transparency range is limited by the lack of design strategies and material candidates. It is therefore necessary to establish a unified and fundamental design principle to provide a basis for identifying correlated TCs with a wider transparency range.…”

Modifying Metastable Sr1–xBO3−δ (B = Nb, Ta, and Mo) Perovskites for Electrode Materials

“…These changes in the absorption profile coincide well with experimental and theoretical reports. 1 , 2 , 34 − 36 The first noticeable color change (from white to light blue, t < 0.5 h) is ascribed to the removal of surface defects that are periodically arranged within the lattice ( Figure 2 a). These defect sites are eliminated during the H 2 /Ar treatment, transforming the initially white powder (insulating) to a light blue (conductive).…”