Semiconductors Used in Photovoltaic and Photocatalytic
Devices: Assessing Fundamental Properties from DFT
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Abstract
The photovoltaic and photocatalytic systems generally use at least
one semiconductor in their architecture which role is to absorb the
light or to transport the charge carriers. Despite the large variety
of working principles encountered in these systems, they share some
fundamental steps such as light absorption, exciton dissociation,
and charge carrier diffusion. These phenomena are governed by fundamental
properties of the semiconductor like the bandgap, the dielectric constant,
the charge carrier effective masses, and the exciton binding energy.
The ability of density functional theory to compute all of these properties
is evaluated. From the particularly good results obtained with the
HSE06 functional, it can be concluded that DFT is a reliable tool
for the evaluation and prediction of these key properties which open
nice perpectives for <i>in silico</i> design of improved
semiconductors for solar energy application. In the light of these
calculations, some experimental observations on the difference of
efficiencies between semiconductors like TiO<sub>2</sub> anatase and
rutile or ZnO are interpreted