Photo-electrochemical and spectroscopic investigation of ALD grown TiO2: Charge transfer characterization and effect of post annealing at different temperature
Research output: Other conference contribution › Paper, poster or abstract › Scientific
|Publication status||Published - 24 Sep 2018|
|Publication type||Not Eligible|
|Event||30th MAX IV user meeting: Coherent visions - Scandic Star Hotel, Lund, Sweden|
Duration: 24 Sep 2018 → 26 Sep 2018
|Conference||30th MAX IV user meeting|
|Period||24/09/18 → 26/09/18|
In this work, TiO2 thin films were deposited on highly doped Si substrate by atomic layer deposition (ALD) technique using tetrakis-dimethylamido titanium (TDMAT) and water as a precursors. In order to understand the influence of ALD parameters on TiO2 film performance in photo-electrochemical cell, ALD growth temperature was varied from 150 °C to 225 °C and film thickness from 20 nm to 50 nm. Further efforts were made to analyze the effect of post-annealing treatment in air on ALD films and its influence on photo-electrochemical water oxidation reaction.
The highest applied bias photon-to-current efficiency for Solar Water Splitting (SWS) was obtained in 30 nm ALD TiO2 film grown at 200 °C after post annealing at 475 °C. Annealing at higher temperatures decreased the photo-activity substantially. X-ray photoelectron spectroscopy analysis of TiO2 (2 nm)/Si samples after annealing in air revealed the onset of interfacial SiO2 formation at 450 °C. SiO2 at the TiO2/Si interface act as a charge transfer barrier with detrimental consequence on SWS on TiO2/Si photo-anode.