Measurements of effective optical reflectivity using a conventional flatbed scanner Fast assessment of optical layer properties

A conventional flatbed scanner equipped with an additional diffusor is used as a means for rapid measurements of an important figure of merit for optical surfaces, the effective reflectance of devices such as solar cells. The application of the technique to multicrystalline silicon wafers with light trapping structures obtained by electrochemical etching is shown. The use of this method for rapid quality control in production environments as well as in the lab is envisaged Even with a non optimized diffusor, a spatial resolution of 0.1x0.1 mm2 can be achieved, with an accuracy of the reflectivity measurements of the order of 1 and data acquisition times around 10 s per wafe