Investigation of side shift and edge losses of surface scattering samples in integrating sphere measurements
(English)In: Applied Optics, ISSN 0003-6935Article in journal (Refereed) Submitted
Light scattering materials are frequently used in solar energy applications, for instance as cover glass in solar thermal absorbers or to increase the path length of photons in solar cells. Knowing the transmittance of such materials is essential to modeling, designing or characterizing a system with these materials as components. The transmittance is traditionally obtained using an integrating sphere spectrophotometer. However, it is known that most commercial spectrophotometers might underestimate the true transmittance of surface scattering samples. Some of the scattered light might hit the edge and escape out of the sample. Thereby the transmitted light exits the sample in such a fashion, that it is not collected by the integrating sphere. The detected signal from the light entering the sphere then underestimates the real transmittance or reflectance of the sample. In this paper this side shift and edge losses of surface scattering samples have been studied and the results show that this might have a significant impact on measured values. Several different techniques have been used to quantify the influence on measurements.
IdentifiersURN: urn:nbn:se:uu:diva-110715OAI: oai:DiVA.org:uu-110715DiVA: diva2:278018