The Solar Cell Scan, from Gilden Photonics and available via distributor Laser 2000, allows researchers to measure quantum efficiency (QE) and incident photon to charge carrier efficiency (IPCE) for photon-to-charge converting equipment, such as devices, including p-n junction and dye-nanocrystalline solar cells (DSSCs).
The system has a unique broadband bias light source. This simulates sunlight intensity, illuminating the device with approximately 1 solar constant. This allows the spectral performance of the device under test to be rigorously evaluated.
QE and IPCE indicate the ratio of the number of photons incident on a solar cell to the number of generated charge carriers. QE is a measure of external efficiency, while IPCE considers the internal efficiency; that is, photons reflected back from the cell surface are not considered.
QE/IPCE measurements are crucial especially during the materials research and cell design stage. These provide development and research teams with critical information regarding optimal spectral response at peak sunlight.
The key to accurately measuring the QE/IPCE of a solar cell is to quantify the intensity of monochromatic light incident to the device under test and how much current is generated as a result. The problem is that the intensity of the monochromatic light is very weak and the response of the solar cell is different dependent upon light intensity.
The Solar Cell Scan provides all necessary components along with a broadband bias light source to simulate the actual operating environment.
Solar Cell Scan comprises a 150W stable Xe light source, Omni-λ monochromator, order sorting filters, and reflective optics. This provides monochromatic light and software selectable broadband light source to a photovoltaic device. The bias source is shuttered when performing the system calibration with the reference detector and then used to bias the test detector and PV solar cell during the measurement. The test detector will respond to this DC light source and the chopped monochromatic beam. An additional detector preamplifier decouples the DC response of the detector to the bias source such that only the AC component of the response is measured.
The system also includes a 200mm traveling X-Y Stage to complete a uniformity scan up to 156 x 156mm PV solar cell.