The influence of oxygen flow rate on properties of SnO2 thin films grown epitaxially on c-sapphire by chemical vapor deposition

Autor: C. Xia, Jie Jiang, Bruno K. Meyer, Yunbin He, Peter J. Klar, Y.M. Lu, B. Kramm, Angelika Polity
Rok vydání: 2015
Předmět:
Zdroj: Thin Solid Films. 594:270-276
ISSN: 0040-6090
DOI: 10.1016/j.tsf.2015.04.010
Popis: Tin dioxide (SnO2) thin films were grown on c-plane sapphire substrates by chemical vapor deposition using SnI2 and O2 as reactants. The growth experiments were carried out at a fixed substrate temperature of 510 °C and different O2 flow rates. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, UV–Vis–IR spectrophotometry and Hall-effect measurement were used to characterize the films. All films consisted of pure-phase SnO2 with a rutile structure and showed an epitaxial relationship with the substrate of SnO2(100)||Al2O3(0001) and SnO2[010]||Al2O3 . The crystalline quality and properties of the films were found to be sensitively dependent on the O2 flow rate during the film growth. The absolute average transmittance of the SnO2 films exceeded 85% in the visible and infrared spectral region. The films had optical band-gaps (3.72–3.89 eV) that are in line with the band gap of single-crystal SnO2. The carrier concentration and Hall mobility of the films decreased from 3.3 × 1019 to 9 × 1017 cm− 3 and from 19 to 2 cm2 V− 1 s− 1, respectively, while the resistivity increased from 0.01 to 3 Ω cm with increasing of the O2 flow rate from 5 to 60 sccm.
Databáze: OpenAIRE