For research laboratories and calibration laboratories analysis the full range of solar cells, starting at sub - mm size, up to 8 inch or 12 inch solar cells, we offer our research spectral response system on an optical table.
The table can span up to 120cm x 240 cm and allows ample, wide area for experimenting.
As a specialty of Optosolar systems, we do NOT change illumination size by using an aperture.This would reduce the light level if small cells are analysed.
Using a special optical system, both small and large area cells will see the same amount of light.
Also, we do NOT image the monochromator exit slit into the measurement plane - this would cause a wavelength variation of the light from left to right.
Our optics 'mixes' the light to have the wavelength distribution more uniform.
And based on early investigations we did while still working at Fraunhofer Callab, our systems are capable to illuminate the full cell area with monochromatic light.
Already then, it was shown that partial illumination can generate errors of up to 20%. Depending on cell material, this cannot be solved by scanning the cell area with a small beam,
because always some part of the cell would be in the dark - interacting with the illuminated part. In the meantime, even IEC recommends full area illumination in their standard on spectral response measurements.
Since Optosolar was founded in 2000, our SR systems are capable to illuminate the full cell area.
Spectral range: any range within 200 nm to 3000 nm. Monochronatic light diameter from mm to > 8/12 inch diameter. This enables full area illumination of the solar cell.
Bias light: white bias light for single junction cells.
Bias light intensity level: up to 1 sun, eve at full area (8/12 inch). Allows to measure solar cells at realistic carrier injection levels.
Cell area: sub - mm to 8/12 in square - special sizes on request
Monochromator: focal length 200mm or 300mm, others on request
Filter wheel with up to 6 blocking filters (to avaoid higher monochromatic light orders from monocromator.
Light chopper, typically 10 Hz - 1000 Hz.
Mirror optics: for a wide spectral range, mirror optics is recommended. This avoids spectral errors due to shift of lens focal length with wavelength
Input lamps: Xenon or Xenon/tungsten combinations. Lamp power between 75W and 1000W, depending on application.
Measurement procedure: AC with dual phase lockin amplifier, DC, (down to < nA upon request).
Light monitor: our systems come in a double beam optic, with a second dual phase lockin for a light monitoring cell.
Sample holder: gold coated, using vacuum suction to hold cell, temperature control 18°C to 50°C (option 10°C to 80°C).
XY scanning of sample holder: manually or automatic with computer control
Cell contacts: double kelvin contacts on top and bottom, with separate contact for current and for cell voltage verification
For information on measurement technoligy in general, please compare the section SR General.