Optimized architecture to maximize solar cell efficiency via the optimal spatial configuration of existing or future transparent thin-film PV materials targeting different regions of the solar spectrum
View Patent ↗A new type of PV cell is comprised of a purposefully unique spatial configuration of multiple pairs of transparent thin PV films stacked top down in order of decreasing bandgaps corresponding to increasing wavelengths. Each thin-film pair is made of a material of desirable bandgap, and consecutive films separated from each other in space by a layer of air to force confinement of light waves of wavelength matching bandgap, enabling an infinite number of reflections until the wave energy corresponding to each desired wavelength is absorbed. The PV thin-films are coated to ensure that light of each wavelength is confined as intended. They are passivated to minimize surface recombination. This spatial arrangement provides multiple opportunities for photovoltaic conversion of each intended wavelength hence increasing overall conversion efficiency.
1 . A photovoltaic (PV) system comprising:
a. A layered sandwiched structure comprised of a plurality of transparent or translucent PV thin-film pairs arranged in layers, with each transparent or translucent PV thin-film pair consisting of two identical transparent or translucent PV thin-films layered in parallel, separated in space by air from each other and from the other transparent or translucent PV thin-film pairs in the layered sandwiched structure, and with each transparent or translucent PV thin-film pair characterized by a unique energy bandgap; and
b. With a member of each transparent or translucent PV thin-film pair characterized by said unique energy bandgap identical to an energy bandgap of the other member of each transparent or translucent PV thin-film pair, and with the unique energy bandgap of each transparent or translucent PV thin-film pair progressively decreasing in magnitude from a top-most transparent or translucent PV thin-film pair to a bottom-most transparent or translucent PV thin-film pair in the layered sandwiched structure, to target absorption of light with progressively longer wavelengths as sunlight traverses down the layered sandwiched structure.
2 . The system of claim 1 wherein each member of each transparent or translucent PV thin-film pair is optically thin and passivated on both sides to minimize recombination and utilizes multiple reflections between both members of each transparent or translucent PV thin-film pair that are separated by said air thereby increasing conversion efficiency for light of a given wavelength which matches the unique energy bandgap of each transparent or translucent PV thin-film pair.
3 . The system of claim 1 further comprising multiple coatings on a top surface of a top member of each transparent or translucent PV thin-film pair and on a bottom surface of a bottom member of each transparent or translucent PV thin-film pair to enable the light of a given wavelength which matches the unique energy bandgap of each transparent or translucent PV thin-film pair to bounce continually between said members of each transparent or translucent PV thin-film pair while enabling light of longer wavelengths to be transmitted downward through the layered sandwiched structure to each transparent or translucent PV thin-film pair below, and enabling light of shorter wavelengths to be reflected upward through the layered sandwiched structure to each transparent or translucent PV thin-film pair above.
4 . The system of claim 1 wherein the air between said member and the other member of each transparent or translucent PV thin-film pair dissipates wasted thermal energy to improve the conversion efficiency of light to electricity.
5 . The system of claim 1 further comprising a battery to store electricity.
6 . The system of claim 1 further comprising a load in a circuit which uses electricity.
7 . The system of claim 4 further comprising a mechanism by which the air between said member and the other member of each transparent or translucent PV thin-film pair can transport the wasted thermal energy to a heat sink for conversion into useful energy.
8 . The system of claim 1 , further comprising a conducting trellis along each transparent or translucent PV thin-film pair to create and maintain an electric field that whisks electrons away as they are created, while also serving to create a skeletal structure to hold each transparent or translucent PV thin-film pair in a spatial configuration to maximize the conversion efficiency from said light to electricity.