Electrical conduction and dielectric properties of poly(methyl methacrylate)/perylene solar concentrators

Abstract

Poly(methyl methacrylate) doped with fluorescent perylene dye was prepared by both radical polymerization of methyl methacrylate and solvent casting from polymer solutions. The samples were characterized by differential scanning calorimetry, Fourier transform infrared spectroscopy, electrical conductivity, and dielectric properties. Both conductivity and dielectric properties were measured in the temperature range 303-433 K and the frequency range 10 3 to 5 ϫ 10 6 Hz. The results show that the directcurrent electrical conductivity increased by increasing dye content in solvent-cast samples, whereas it decreased radically polymerized samples. The results of alternating-current conductivity suggest electron hopping between filled and empty localized states. The study of dielectric properties showed two relaxation peaks corresponding to the dipole segmental and dipole group losses. Explanations based on the polymer free volume and acid-base interactions were proposed to examine the influence of the sample preparation and perylene dye concentration on the glass-transition temperature and dielectric relaxation of the samples. The obtained results recommend the thermal and molecular stability of luminescent solar concentrator (LSC) matrices prepared by radical polymerization over those prepared by solvent casting.

Bent fluorescent solar concentrators (BFSCs): Spectroscopy, stability and outdoor performance

“…6 shows the directly measured hourly values of g opt for all the investigated BFSCs. One notices for b > 160°t hat g opt increases near both sunrise and sunset and gets lower at midday in agreement with our published work [3]. On the other hand, for b 6 160°the behavior is quite different; the value of g opt reaches a stationary value for as long as 7 h around midday and records lower values at both sunrise and sunset.…”

“…It is clearly illustrated that the ratio J sc /J rc reaches a value of 7 during more than 6 h around midday for an apex angle of 150°, corroborating the large light concentration effect achieved by the BFSCs. It is also observed that the ratio J sc /J rc exceeds this value near sunrise and sunset; from the practical point of view this behavior is advantageous, since better utilization of the FSC is achieved as both the direct solar radiation component and the sensitivity of PV cell decreases [3]. Fig.…”

“…The fluorescent photons are trapped by total internal reflection and concentrated at the edges of the concentrator, where they can be converted to electricity by appropriate (PV) cells. FSCs have the following advantages over conventional solar concentrators (focusing concentrators): they collect both direct and diffused light; there is a good heat dissipation the of non-utilized energy by the large area of the concentrator plate in contact with air so that essentially ''cold light'' reaches the (PV) cells; tracking the sun is unnecessary; the luminescent species can be chosen to allow the matching of the concentrated light to the maximum sensitivity of the (PV) cells [2,3]. In this paper, we introduce a new ''bent'' configuration of BFSCs.…”

Enhancement of the magnetic and dielectric properties of cobalt nanoferrite/polymethyl methacrylate composites

“…This can be understood according to the presence of the ester functional group, with the carbonyl oxygen atom being a basic site, leads to PMMA exhibiting electrondonor ability. So, PMMA is described as a basic polymer containing an electron-donor atom [16]. Hence, the polarization process occurs by electron jumping (hopping and/or tunneling) between donor atoms and empty sites located in the energy band gap.…”

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

“…The physical properties of PMMA have led to its extensive use in outdoor electrical applications [6][7][8][9]. According to the published literature, it was found that its optical properties have been extensively studied [5,10] while its electrical properties still need much more research.…”