Terahertz absorption properties of YBa2Cu3O7−δ superconductor: thin films grown using a nontoxic, simple spin-coating method

Abstract

ABSTRACT Using terahertz (THz) spectroscopy, high-quality YBa2Cu3O7−δ (YBCO) thin films grown on Si substrates using a simple and nontoxic ethanolamine-based solvent spin-coating method were analysed. As per X-ray diffraction (XRD) and Raman spectroscopic analyses, higher annealing temperatures were increasingly appropriate for growing YBCO thin films. Si substrates were better than Eagle substrates for growing YBCO thin films because of the differences in the crystal structures of these substrates. For the first time, we herein report the THz spectroscopic analysis of YBCO bulk and thin film crystals. In the spectra of both YBCO bulk crystals and thin films, common THz absorption peaks were observed at ∼3.0, 4.5 and 5.3 THz. Moreover, the THz spectra of YBCO thin films deposited on the Si substrates, using a nontoxic ethanolamine-based solvent, show peaks similar to those in the spectrum of the corresponding bulk crystals. Our proposed method is an advancement for developing high-performance superconducting films.