Conclusion
The test setup allows to conduct various photoelectrochemical
measurements (e.g., STH determination) and can help to avoid common
problems with equipment. It allows the use of standard vertical solar
simulators by reflecting the light to the electrochemical cell with a
solar-grade mirror. The light in the plane of the photoelectrode had a
high spectral quality, a low spatial non-uniformity and a low temporal
instability, resulting in an AAA classification (IEC 60904-9). A system
for temperature control with an external Peltier element allows
measurements at constant temperature (±1 °C) in the range of 20–45 °C.
It enables automated time resolved measurements with enhanced
metrological precision and the investigation of the temperature
dependency of photoelectrochemical reactions. Gas analysis is carried
out with a mobile GC, which is equipped with a thermal conductivity
sensor, two short columns and an internal gas supply. It makes use of an
automated measurement routine with discontinuous sampling from the
reactor cell. A software for data evaluation calculates Faraday and STH
efficiencies and allows the correction of leakage. The system was
applied to investigate a copper indium gallium selenide photocathode in
H2SO4, for which a Faradaic efficiency
of (95.4±7.7) % was determined.