Structural, Optical and Sensing Properties of Cr-Doped TiO2 Thin Films
Undoped and chromium (Cr)-doped TiO2 thin films were deposited at room temperature by the RF magnetron sputtering method onto oxidized silicon. The composition, microstructure and surface morphology of the sputter-deposited films were studied by means of X-ray Photoelectron
Spectroscopy (XPS), X-ray diffraction (XRD) and atomic force microscopy (AFM) respectively. The deposited films were found to be mainly amorphous. The Cr incorporation induces a more compact films compared to undoped ones. Using variable angle spectroscopic ellipsometry the optical constants
(n and k) and energy band gap of the Cr-doped films were found to depend on their Cr content. Thus, the band gap of the TiO2:Cr films can be varied from 3.3 eV to 1.89 eV by increasing their Cr content. The TiO2:Cr films were integrated into gas sensing
devices and their sensing properties (sensor response, response and recovery time) towards ethanol were systematically investigated as a function of their Cr content. This has led to identify an optimum Cr-doping condition, which corresponds not only to the highest sensor response but also
to the shortest response and recovery time of the sensors. The deposited TiO2 films shows an n-type conducting behaviour for Cr doping concentration lower than 13% however a p-type conduction is observed at higher doping content.
Keywords: BANDGAP; CHROMIUM; ETHANOL SENSING; RF-SPUTTERING; TIO2
Document Type: Research Article
Publication date: 01 October 2011
- The growing interest and activity in the field of sensor technologies requires a forum for rapid dissemination of important results: Sensor Letters is that forum. Sensor Letters offers scientists, engineers and medical experts timely, peer-reviewed research on sensor science and technology of the highest quality. Sensor Letters publish original rapid communications, full papers and timely state-of-the-art reviews encompassing the fundamental and applied research on sensor science and technology in all fields of science, engineering, and medicine. Highest priority will be given to short communications reporting important new scientific and technological findings.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites
- Access Key
- Free content
- Partial Free content
- New content
- Open access content
- Partial Open access content
- Subscribed content
- Partial Subscribed content
- Free trial content