Authors: Nicholas Thompson and Harry L. Tuller (in collaboration with group of Professor Marc Baldo)
Sponsor: MIT Energy Frontier Research Center on Excitonics, Department of Energy
Luminescent solar concentrators (LSCs) are optically concentrating devices for harnessing solar power that do not require sun tracking. Light incident on the thin rectangular waveguide is absorbed by a luminescent species which then remits the light at a wavelength tailored for the photovoltaic device mounted on the edge. The photovoltaic device then converts the concentrated light into electricity.
In this project, we are using the optoelectronic processes shownto increase the efficiency of organic solarconcentrators to improve the performance of an inorganic LSC in the solar spectrum. One promising type of inorganic LSC is based on rare earth doped glasses.
These glasses exhibit emission near the bandgap of highly manufacturable silicon photovoltaic devices, but their absorbance is poorly overlapped with the visible spectrum. Sensitizing the rare earth atom with a broadly absorbing transition metal will increase the amount of the solar spectrum harnessed by the LSC. Important aspects of the system’s efficiency include the absorption cross-section of the transition metal, the photoluminescence efficiency of each species, and the chemical structure of the glass.