IMPS/IMVS to evaluate carrier transport time, recombination rates and other time scales

Description

The IMPS/IMVS instrument allows to perform sample examination that is complementary to static photovoltage/photocurrent measurements. Monochromatic LED with modulated light intensity of sinusoidal waveform in wide range of frequencies enables to investigate many kinetic quantities: diffusion parameters, time scales of the sample: carrier transport time, recombination rates and many others. In case of photoelectrochemical samples immersed in an electrolyte, the sample may be illuminated on both sides: through the electrolyte, to investigate electrolyte-sample surface interface, or through the rear optical window for substrate-sample interface examination. The sample setup is placed in the Sample Chamber that screens ambient light and external EM fields.

Quantities measured by the instrument:
Minority carriers lifetime (recombination time),
Carrier transport time through the sample,
Rate of the charge transfer through the interfaces,
Diffusion constant,
Diffusion length for a given sample thickness,
Sample thickness for a given diffusion length,
Other kinetic quantities.

IMPS/IMVS modules
The instrument consists of:

LED Revolver light source,
Potentiostat for photocurrent and Open Circuit Potential (OCP) measurement,
Sample Chamber that shields the sample from an external EM fields as well as from ambient light,
Electrochemical Cuvette with Pt and Ag/AgCl electrodes.

Specifications