Abstract
We report on terahertz characterization of La-doped BaSnO3 (BSO) thin-films. BSO is a transparent complex oxide material, which has attracted substantial interest due to its large electrical conductivity and wide bandgap. The complex refractive index of these films is extracted in the 0.3 to 1.5 THz frequency range, which shows a metal-like response across this broad frequency window. The large optical conductivity found in these films at terahertz wavelengths makes this material an interesting platform for developing electromagnetic structures having a strong response at terahertz wavelengths, i.e. terahertz-functional, while being transparent at visible and near-IR wavelengths. As an example of such application, we demonstrate a visible-transparent terahertz polarizer.
Highlights
Transparent electronics have garnered significant attention since the introduction of the first transparent thin film transistor[1,2,3]
For the purposes of THz characterization, we employed the THz time-domain spectroscopy (THz-TDS) technique as our primary characterization tool. This technique is unique, because it allows for measurement of the THz electric field through the BSO/LSAT samples
Our doped BSO films show one of the largest electrical conductivities in any transparent conductive oxides (TCOs) demonstrated to date, which is on par with the best reports in ITO
Summary
Transparent electronics have garnered significant attention since the introduction of the first transparent thin film transistor[1,2,3]. Several types of transparent conductive oxides (TCOs) have been introduced and characterized for different applications in areas including plasmonics and photovoltaics. These include tin-doped indium oxide (ITO), gallium-doped zinc oxide (GZO), and aluminum-doped zinc oxide (AZO), among others[4]. High mobility in BSO at room-temperature has been attributed to low electron effective mass and to weak phonon scattering These characteristics, combined with a wide band-gap of 3 eV, an ultra-high conductivity and relatively high mobility in thin films, make BSO a strong candidate as a transparent conducting oxide. Our results reveal BSO as an efficient visible-transparent THz-functional material in addition to establishing new avenues of research in this novel wide band-gap oxide films as well as new potential TCO applications. Samples #2 and #3 with barium and tin deficiencies showed mobilities of 71 and 17 cm2/V.s, respectively, consistent with higher disorder due to non-stoichiometry[21]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
