Optical and microstructural properties of p-type SrCu 2O 2: First principles modeling and experimental studies

Abstract

In this paper, we report first principles calculations and experimental studies of the optical and microstructural properties of both bulk and thin films of SrCu 2O 2. Polycrystalline SrCu 2O 2 films were grown by a conventional Pulsed Laser Deposition method in a flowing oxygen environment on corning glass 7059 and silicon substrates. Several characterization techniques, including X-ray diffraction (XRD), Fourier Transform IR (FTIR), Raman, spectroscopic ellipsometry, reflectance/transmission spectrophotometry and Atomic Force Microscopy have been used for the investigation of the microstructural and vibrational properties of both bulk and thin films of SrCu 2O 2. XRD shows that bulk SrCu 2O 2 is polycrystalline and assumes the pure tetragonal phase of SrCu 2O 2. The vibrational properties of the tetragonal phase of SrCu 2O 2 have been inferred from Raman and FTIR spectroscopies and for the first time both Raman and IR active modes have been assigned. The bulk polycrystalline SrCu 2O 2 optical band gap determined from spectroscopic ellipsometry was 3.34 ± 0.01 eV. XRD results confirmed that pure non-textured polycrystalline phase SrCu 2O 2 thin films with a smooth surface can be grown by PLD at low temperature (300 °C).