Method and means for a high power solar cell

Abstract

In methods and apparatus for improving the power generated, and thus efficiency of solar cells, a double or triple junction tandem solar cell that has one or two photon filters of the invention in between the solar cell layers, respectively. The photon filter is arranged to reflect photons with wavelength shorter than λx and arranged to be transparent to photons of wavelength longer than λx by focussing the lower energy photons out of small area apertures on the other side of the photon filter and arranging the other side of the photon filter to reflect at least some of the photons of wavelength longer than λx. By using the photon filters of the invention in between the solar cell layers, photons can be trapped between filters to solar cell layers at an energy at which the quantum efficiency of the solar cell layer is the best.

1 . A terrestrial electric vehicle,
 comprising: a camouflaged multijunction   solar cell,   wherein the multijunction solar cell has band gap matching emission peak of indoor Light Emitting Diode LED and/or fluorescent light, and one said band gap is in the 400-500 nm range, and   the multijunction solar cell is configured to be powered by the indoor lights to charge or power the electric vehicle, and the multijunction solar cell has a first semiconductor layer serving as a first solar layer cell layer, a second semiconductor layer serving as a second solar cell layer, a third semiconductor layer serving as a third solar cell layer, a first photon filter located between the first and second semiconductor layers, and a second photon filter located between the second semiconductor layer and third semiconductor layer, wherein the solar cell is camouflaged and installed on the electric vehicle and powers the electric vehicle motor electrically, charges the battery, or powers electric appliances for the electric vehicle.   
     
     
         2 . The terrestrial electric vehicle as claimed in  claim 1 , further comprising one or more of at least one piezoelectric crystal and at least one mechanical device each configured to generate electricity from mechanical movement of the terrestrial electric vehicle. 
     
     
         3 . The terrestrial electric vehicle as claimed in  claim 1 , wherein the at least one multijunction solar cell has buried electrical contacts.