Type

Journal Article

Authors

Denis P. Dowling
J. M. Don MacElroy
Mahfujur Rahman
Binh H.Q. Dang

Subjects

Physics

Topics
phase transformation titanium dioxide films microwave plasma phase transformations statistical physics magnetrons sputtering physics microwave plasmas magnetron sputtering titanium dioxide carbon doping

Conversion of amorphous TiO2 coatings into their crystalline form using a novel microwave plasma treatment (2011)

Abstract Crystalline titanium dioxide (TiO2) coatings have been widely used in photo-electrochemical solar cell applications. In this study, TiO2 and carbon-doped TiO2 coatings were deposited onto unheated titanium and silicon wafer substrates using a DC closed-field magnetron sputtering system. The resultant coatings had an amorphous structure and a post-deposition heat treatment is required to convert this amorphous structure into the photoactive crystalline phase(s) of TiO2. This study investigates the use of a microwave plasma heat treatment as a means of achieving this crystalline conversion. The treatment involved placing the sputtered coatings into a 2.45 GHz microwave-induced nitrogen plasma where they were heated to approximately 550°C. It was observed that for treatment times as short as 1 minute, the 0.25-µm thick coatings were converted into the anatase crystalline phase of TiO2. The coatings were further transformed into the rutile crystalline phase after treatments at higher temperatures. The doping of TiO2 with carbon was found to result in a reduction in this phase transformation temperature, with higher level of doping (up to 5.8% in this study) leading to lower anatase-to-rutile transition temperature. The photoactivity performance of both doped and un-doped coatings heat-treated using both furnace and microwave plasma was compared. The carbon-doped TiO2 exhibited a 29% increase in photocurrent density compared to that observed for the un-doped coating. Comparing carbon-doped coatings heat-treated using the furnace and microwave plasma, it was observed that the latter yielded a 19% increase in photocurrent density. This enhanced performance may be correlated to the differences in the coatings’ surface morphology and band gap energy, both of which influence the coatings’ photoabsorption efficiency.
Collections Ireland -> University College Dublin -> Solar Energy Conversion (SEC) Cluster
Ireland -> University College Dublin -> Chemical and Bioprocess Engineering Research Collection
Ireland -> University College Dublin -> Mechanical & Materials Engineering Research Collection
Ireland -> University College Dublin -> Institutes and Centres
Ireland -> University College Dublin -> School of Electrical and Electronic Engineering
Ireland -> University College Dublin -> Electrical and Electronic Engineering Research Collection
Ireland -> University College Dublin -> Solar Energy Conversion (SEC) Cluster Research Collection
Ireland -> University College Dublin -> College of Engineering & Architecture
Ireland -> University College Dublin -> School of Chemical and Bioprocess Engineering
Ireland -> University College Dublin -> School of Mechanical and Materials Engineering

Full list of authors on original publication

Denis P. Dowling, J. M. Don MacElroy, Mahfujur Rahman, Binh H.Q. Dang

Experts in our system

1
Denis P. Dowling
University College Dublin
Total Publications: 50
 
2
J. M. Don MacElroy
University College Dublin
Total Publications: 46