| 摘要 |
The invention relates to methods and means for improving the power generated, and thus efficiency of solar cells (20, 30). The best mode of the invention at present is considered to be a double or triple junction tandem solar cell (20, 30) that has one or two photon filters (100, 101) of the invention in between the solar cell layers (200, 201, 202, 203), respectively. The photon filter (100, 101, 102) is arranged to reflect photons with wavelength shorter than ?x and arranged to be transparent to photons of wavelength longer than ?x by focussing the said lower energy photons out of small area apertures (140, 141) on the other side of the photon filter (100, 101, 102) and arranging the other side of the photon filter (100, 101, 102) to reflect (150, 151) at least some of the said photons of wavelength longer than ?x. By using the photon filters (100, 101, and 102) of the invention in between the solar cell layers (200, 201, 202, and 203), photons can be trapped between filters to solar cell layers at an energy at which the quantum efficiency (QE) of the solar cell layer is the best. |
