New luminescent back reflectors for the improvement of the spectral response and efficiency of luminescent solar concentrators

Abstract

The effects of various types of back reflector on the behaviour of luminescent solar concentrators (LSCs) are considered with special attention given to diffusing back reflectors. Two main configurations, i.e. the independent diffusing back reflector and the direct deposition of a reflective material onto the back surface of an LSC, have been theoretically and experimentally analysed. The experimental results show that a diffusing back reflector allows a partial trapping of the light not absorbed by the LSC. This phenomenon is enhanced by the direct deposition of a reflective material onto the back surface of the LSC but results in this case in the degradation of the light-guiding properties of the LSC. We have taken advantage of this apparently negative effect in the design of a new type of luminescent back reflector with improved performance.