External and internal quantum efficiency of solar cells, Transmittance and reflectance in the range from 200nm to 1100nm.

We dispose of a system for photovoltaic material and device spectral characterisation. It permits quick and accurate determination of solar cell spectral response/ EQE (IPCE). The additional measurement of cell transmittance and reflectance allows the determination of IQE in a spectral range of 300-1100 nm. The sample under test is mounted horizontally on a temperature controlled vacuum mount for thermal stability. A monochromatic probe is made to be incident upon the sample under test; at each wavelength is measured the photocurrent generated by the device. Having measured the beam power with a detector of known responsivity, spectral response and EQE can be directly obtained. Intervening a divert mirror in the beam relays the monochromatic probe to a 6” diameter integrating sphere, mounted on an optical rail to the upper of the chamber, for the measurement of device total reflectance and total transmittance. The EQE may be modified by these latter measurements to determine the more fundamental parameter of IQE.