The photoelectric spectrometer serves as a scientific tool to automatically characterize photoelectrical properties (photocurrent, photovoltage) of wide band gap semiconductors illuminated by relatively strong light in UV, VIS and NIR ranges as a function of incident light wavelength.
To approximate solar light for many applications we offer Air Mass Filters. These filters modify the spectral output of the arc lamp to mimic natural solar conditions.
Quantities measured by the instrument:
- electric current in the sample (chronoamperometry, CA)
- open circuit potential (OCP)
- photocurrent of the sample illuminated with white or monochromatic light
- current-voltage characteristics
- light transmittance of the sample (with calibrator)
- light intensity on the sample (with calibrator)
- open circuit potential (OCP) as a function of light wavelength
- action maps (photocurrent as a function of potential and wavelength)
- IPCE maps as functions of potential and wavelength
- sample reflectance (with integrating sphere)
- APCE (Absorbed Photons to Converted Electrons) maps as potential and wavelength function
- current-voltage characteristics under illumination
- work function of a sample (with Kelvin probe)
- work function of a sample under illumination (with Kelvin probe)
Advanced software of the spectrometer allows for straightforward recording of photocurrent action spectra, photovoltage action spectra along with potentiodynamic and galvanodynamic measurements at constant wavelenght both in CW and pulsed mode. It also provides Incident Photon to Converted Electron (IPCE) ratio and, with integrating sphere, Absorbed Photon to Converted Electron (APCE) ratio as a function of wavelength and bias potential.
Furthermore, the device can be coupled with other detectors, including Kelvin probes, conductivity probes, etc. The devices’ controller takes care of emitted light wavelength, exposition times, proper light edge filters handling and synchronization with a potentiostat.
The monochromator is equipped with two switchable gratings to uniformly cover a wide light spectrum. The light power exceeds 10 mW/cm2) in most of the spectral range.
- Sample Chamber
- Monochromator for UV, VIS and IR light
- Potentiostat for full characterisation of electrochemical samples
- Xenon Lamp with the controller and water cooling system
- Electrochemical cuvette with Pt working electrode and Ag/AgCl reference electrode
- FotoGUI software
Inside the Sample Chamber
The parameters shown beneath are typical for the devices produced so far. All of them can be tailored to specific requirements if necessary.
- Light source: Xe 150 W, water cooled, with low EM emission igniter
- Light stabilization modes: current stabilization (distortions < 1%), power consumption stabilization and light intensity stabilization mode that keeps the illumination of a sample constant during the experiment.
- Up to four gratings
- Maximal light power density: 35 mW/cm2
Additional equipment:
The Photoelectric Spectrometer is adapted to extend its functionality by connecting with other instruments, such us Kelvin Probe, LED Revolver, temperature controller and others.
- Edge (long pass) filters: 400 nm and 510 nm
- Up to 6 filters possible
- Number of I/O programmable TTL lines for synchronization with external devices: 16
- Connectivity: USB 2.0
Typical light intensity output of the photoelectric spectrometer
The light intensity produced by the photoelectric spectrometer varies with the wavelength (top plot) and with slit opening (bottom plot). In the picture, a typical light intensity generated with 150 W xenon lamp and two 1200 gr/mm gratings: optimized for 300 nm and for 500 nm.
click the photo to enlarge
The spectrometer can be used for automatic measurements and visualization of obtained results. At the top, there is a typical photocurrent action map. It is photocurrent values versus light wavelength and applied potential.
3-dimensional action map of photocurrent in relation to the light wavelength and potential applied.
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