Electric and Dielectric Properties of Some Fluorescent Dye/PMMA Solar Concentrators

The effect of dye concentrations of perylene, RH-6G and K-1 doped in polymethylmethacrylate (PMMA) as matrix material, on the electrical properties of some fluorescent solar concentrator (FSC) have been investigated. The samples were prepared by dissolving grains of both PMMA and dyes in chloroform, which were then left at room temperature to evaporate the solvent. The samples were characterized by differential scanning calorimeter (DSC). The results of both dc conductivity (sigma(dc)) and ac conductivity (sigma(ac)) showed that the total conductivity sigma(tot)(w) is higher than sigma(dc) and the activation energy of sigma(tot) is lower than that of (sigma(dc)) due to the increase of the applied field frequency, which enhances the carrier jumping and subsequently the conductivity value. The dielectric properties (dielectric constant (epsilon'), dielectric loss (epsilon `'), and dielectric tangent (tan delta) have been studied. They show that epsilon' increases by increasing the concentration of the dyes doped in PMMA. All the dielectric constants, the dielectric loss and loss tangent temperature dependence, show a peak value affected by the dye concentration as well the frequency changes. The temperature dependence of the exponent S shows that at low temperature the conduction obeys a quantum mechanical tunnel model, while at high temperature the conduction obeys the correlated barrier-hopping model.