An irradiance-mode absolute differential spectral response measurement system based on a light emitting diode (LED) array is described. The LEDs are coupled to an integrating sphere whose output irradiance is uniform to better than 2 % over an area of 160 mm by 160 mm. Diffuse irradiation of solar cells by the sphere is compared with collimated irradiance measurements, and issues originating from the differences in angular response of the reference and the test cells are further investigated. Large-area cells with dimensions of up to 155 mm are measured and the short circuit current (Isc) of the cells under the AM 1.5 standard reference spectrum is calculated and is shown to have good agreement with the secondary calibration measurements.
Citation: Applied Optics
Pub Type: Journals
photovoltaics, solar cell, measurements, physics, light emitting diodes, integrating sphere