1 research outputs found
Charge Transfer Characterization of ALD-Grown TiO<sub>2</sub> Protective Layers in Silicon Photocathodes
A critical
parameter for the implementation of standard high-efficiency
photovoltaic absorber materials for photoelectrochemical water splitting
is its proper protection from chemical corrosion while remaining transparent
and highly conductive. Atomic layer deposited (ALD) TiO<sub>2</sub> layers fulfill material requirements while conformally protecting
the underlying photoabsorber. Nanoscale conductivity of ALD TiO<sub>2</sub> protective layers on silicon-based photocathodes has been
analyzed, proving that the conduction path is through the columnar
crystalline structure of TiO<sub>2</sub>. Deposition temperature has
been explored from 100 to 300 °C, and a temperature threshold
is found to be mandatory for an efficient charge transfer, as a consequence
of layer crystallization between 100 and 200 °C. Completely crystallized
TiO<sub>2</sub> is demonstrated to be mandatory for long-term stability,
as seen in the 300 h continuous operation test