Synchronous Multi Spectral DTR (OIS) with Parallel Impedance Measurement System - With this option your CIMPS system gets the ability to investigate electrochromic systems, displays, PDLCs, smart windows...
Exceptional feature: assigns kinetic information unequivocally to certain colored species in a reaction chain!
Some physical systems change their optical properties under the influence of an electrical voltage or current applied. Such behavior is of high scientific interest and reached already great economic importance in the fields of electronic displays, smart windows and electronic newspapers, acting as electro-chromic devices.
The electric control of the absorbance may have influence on the spectral properties of such systems. Dependent on the state, color or tone may change, what can be investigated quantitatively by means of CIMPS-abs. For many applications, besides color aspects, the dynamic properties are of high importance as well. The switching time, very important for instance for displays and modulators or the reaction time of smart windows is determined by the kinetic processes of transport- and Redox-reactions or structural re-organization which cause the optical changes.
Dynamic Transmittance Reflectance "DTR" transfer function analysis, also known as OIS (Optical Impedance Spectroscopy), follows the ideas popular for instance in Electrochemical Impedance Spectroscopy. The basic transfer function in EIS is given between voltage and current. Like for EIS, in DTR a bias control voltage (or current) applied to the sample is modulated by a small test signal amplitude. Differing from EIS, the sample is illuminated using a certain calibrated static intensity P, and the transmitted or reflected light P* is recorded and treated as response signal in dependence of the electrical modulation.
The dynamic transfer function DTR is calculated as the quotient between the response modulation signal (the relative intensity change in time P*/P = TR* ) and the force modulation signal (Voltage U* or current I*, dependent on the mode chosen, potentiostatic or galvanostatic). In the frequency domain, the time dependency of both signals can be cancelled out in the quotient, apart from a characteristic phase shift φ which may depend on the frequency ω.
DTR spectra can be understood in principle like EIS. Time constants can be extracted and assigned to certain charge transfer, relaxation and transport processes, and their characteristic shape and phase angle helps to distinguish between them.
It is known, that EIS suffers from the ambiguity of the spectra: different mechanisms may lead to identical dynamic transfer functions. It is an exceptional property of DTR, that the response function can be assigned unequivocally to an occuring colored species. In combination with EIS, DTR may help to cancel out further ambiguities, like it can be done also in combination with IMPS/IMVS data. DTR can be performed with most calibrated light sources of different spectral properties from the Zahner portfolio. By changing the wavelength, DTR may be extended selectively to the case, when more than one colored species is present.
DTR gives valuable dynamic information which belongs to a certain bias within the systems steady state characteristic. Besides, CIMPS-dtr supports slow, quasi-static scan features determining the steady state characteristics. In order to characterize the static transmittance-reflectance behavior in dependence of the applied voltage, the sample voltage can be swept linearly between two limiting voltages under potentiostatic control. In galvanostatic mode the TR-characteristic recording is supported in form of a charge scan.
- Dynamic transmittance / reflectance vs. frequency
- Opitical impedance spectroscopy
- Static transmittance / reflectance vs. charge
- Static transmittance / reflectance vs. voltage
- Static transmittance / reflectance vs. time
- Multi spectral transmittance / reflectance vs. frequency with synchronous parallel impedance (only mdtr/ois)
CIMPS add-on option for dynamic transmittance/reflectance measurements
Requirements: Basic CIMPS system
Download the latest information brochure about ZAHNER CIMPS system...
Download the latest manual add-on about ZAHNER CIMPS-mdtr/ois option for synchronous multi spectral dynamic transmittance / reflectance measurements (setup with PAD4 addon card)...
Download the latest manual add-on about ZAHNER CIMPS-dtr option for dynamic transmittance / reflectance measurements (setup with second external Potentiostats)...
Download the latest manual add-on about ZAHNER CIMPS system...