Intensity-modulated photocurrent spectroscopy (IMPS)
has been largely
employed in semiconductor characterization for solar energy conversion
devices to probe the operando behavior with widely available facilities.
However, the implementation of IMPS data analysis to complex structures,
whether based on the physical rate constant model (RCM) or the assumption-free
distribution of relaxation times (DRT), is generally limited to a
semi-quantitative description of the charge carrier kinetics of the
system. In this study, a new algorithm for the analysis of IMPS data
is developed, providing unprecedented time resolution to the investigation
of μs to s charge carrier dynamics in semiconductor-based systems
used in photoelectrochemistry and photovoltaics. The algorithm, based
on the previously developed DRT analysis, is herein modified with
a Lasso regression method and available to the reader free of charge.
A validation of this new algorithm is performed on a α-Fe2O3photoanode for photoelectrochemical water splitting,
identified as a standard platform in the field, highlighting multiple
potential-dependent charge transfer paths, otherwise hidden in the
conventional IMPS data analysis.