Multi-Junction solar cell metrology is more complicated than that of a single junction one. As these cells are made of multiple layers, a multi-source/LED solar simulator is usually employed to allow adjustment of band to band irradiance ratios. Our triple junction reference cells can be used to set the correct irradiance for each single junction.
The device consists of 4 x 1cm2 cells mounted in an area of 2 x 2 cm. Calibration data is provided for the three (3) individual component cells. A component cell is a single junction cell but made exactly the same as a the triple junction cell. So each component has three layers where only layer is electrically active.
As an example the middle component cell consists of a layer of InGaP (top), InGaAs (middle), and Ge (bottom). Only the InGaAs is made electrically active, so you measure a single junction InGaAs cell. Since there is an (inactive) InGaP cell on top the blue part of the spectrum is filtered. This results in a different spectral response for the InGaAs Cell. This allows you measure what the InGaAs cell would ‘see’ in the stack of a normal triple junction cell while avoiding current limiting contributions of other layers.Download the data sheet here