Terrestrial solar power system using III-V semiconductor solar cells

Abstract

A system for generating electrical power from solar radiation utilizing a III-V compound multijunction semiconductor solar cell; a concentrator for focusing sunlight on the solar cell, including a concave trough-shaped reflector; and a heat spreader connected to the solar cell for cooling the cell.

1 . A system for generating electrical power from solar radiation comprising:
 a III-V compound semiconductor solar cell;   a concentrator for focusing sunlight on the solar cell, including a concave trough-shaped reflector;   a solar tracker coupled to said concentrator so as to align the concentrator with the rays of the sun as the sun traverses the sky so that the sunlight is focused on the solar cell;   a heat spreader connected to said solar cell for cooling said cell; and   an electrical circuit connected to said solar cell for transferring electrical energy from said cell.   
     
     
         2 . A system as defined in  claim 1 , wherein said heat spreader is a metal structure with cooling fins. 
     
     
         3 . A system as defined in  claim 1 , wherein said heat spreader is water cooled. 
     
     
         4 . A system as defined in  claim 1 , wherein said solar cell is an inverted metamorphic cell with an insulated via extending therethrough so that the anode and cathode contacts are on one side thereof. 
     
     
         5 . A thin, flexible solar cell comprising a semiconductor body including a first solar subcell on the substrate having a first band gap;
 a second solar subcell disposed over the first subcell and having a second band gap smaller than the first band gap;   a grading interlayer disposed over the second subcell having a third band gap larger than the second band gap;   a third solar subcell disposed over the second solar subcell such that the third solar subcell is lattice mis-matched with respect to the second subcell and the third subcell has a fourth band gap smaller than the third band gap; and   a support for mounting the solar cell in a non-planar configuration so as to capture the parallel rays of the incoming sunlight in a concentrator so that the rays are substantially perpendicular to the surface of the semiconductor body.   
     
     
         6 . A solar cell module comprising:
 a thin film semiconductor body including a multijunction solar cell and first and second electrical contacts on the back surface thereof;   a support for mounting said solar cell and making electrical contact with said first and second contacts; and   a heat spreader attached to said support for dissipating heat from said semiconductor body.   
     
     
         7 . A module as defined in  claim 6 , wherein said semiconductor body is composed of a III-V compound semiconductor. 
     
     
         8 . A module as defined in  claim 7 , wherein said support is composed of copper and has first and second electrically isolated regions for making electrical contact with said first and second contacts respectively. 
     
     
         9 . A module as defined in  claim 6 , wherein said heat spreader includes cooling fins. 
     
     
         10 . A multijunction solar cell comprising:
 a semiconductor body;   a first solar subcell in said body having a first band gap;   a second solar subcell in said body disposed adjacent said first subcell in said body and having a second band gap smaller than said first band gap;   a grading interlayer disposed adjacent said second subcell in said body and having a third band gap greater than said second band gap; and   a third solar subcell disposed adjacent said interlayer in said body and not being lattice mis-matched with respect to said second subcell and having a fourth band gap smaller than said third band gap.