Solar cell receiver for concentrated photovoltaic system for iii-v semiconductor solar cell

Abstract

A solar cell module comprises an array of lenses, corresponding secondary optical elements and corresponding solar cell receivers. The solar cell receiver includes a solar cell having one or more III-V compound semiconductor layers, a diode coupled in parallel with the solar cell and connector for coupling to other solar cell receivers. The module includes a housing that supports the lenses such that each lens concentrates solar energy onto its respective solar cell.

1 . A solar cell module for converting solar energy to electricity comprising:
 a housing comprising a first side and a second side opposite to the first side;   an integral array of Fresnel lenses coupled to the first side of the housing;   a plurality of solar cell receivers disposed on the second side of the housing, each solar cell receiver comprising:
 a solar cell comprising one or more III-V compound semiconductor layers wherein the solar cell has dimensions of about 1 centimeter by about 1 centimeter; 
 a diode having a body, an anode terminal and cathode terminal, wherein the diode is coupled in parallel with the solar cell and the diode body comprises a top portion and a bottom portion; 
 first and second electrical terminals coupled in parallel with the solar cell and the diode and adapted to provide electrical connection to one or more spaced apart solar cell receivers; 
 a substrate for supporting the solar cell and diode wherein the bottom portion of the diode body is disposed closer to the substrate than the top portion of the diode body; 
 a coating disposed over the top portion of the diode body and extending to the substrate, the coating substantially encapsulating the diode body, anode terminal and cathode terminal; and 
 an undercoating occupying substantially all of the space between the bottom portion of the diode body and the substrate; 
   a plurality of secondary optical elements disposed in the optical path of each respective lens, each secondary optical element defining a respective tapered optical channel having a plurality of reflective walls;   each solar cell being disposed in an optical path of a respective lens and a respective optical channel, wherein the lens is operable to concentrate the solar energy onto the respective solar cell by a factor of 400 or more and generate in excess of 14 watts of peak power.   
     
     
         2 . The solar cell module of  claim 1  wherein each Fresnel lens has a focal length between about 15 inches and about 20 inches. 
     
     
         3 . The solar cell module of  claim 1  wherein the undercoating is disposed such that there is no air gap between the diode and the substrate. 
     
     
         4 . The solar cell module of  claim 1  wherein the integral array of Fresnel lenses is an acrylic sheet having an alignment element adapted to couple with an alignment element on the housing. 
     
     
         5 . The solar cell module of  claim 1  wherein the focal length of each Fresnel lens is about 17.75 inches. 
     
     
         6 . The solar cell module of  claim 1  wherein the solar cell is a multijunction cell comprising at least three regions wherein the regions respectively comprise a germanium containing substrate, an InGaAs or GaAs containing layer disposed on the substrate, and a layer of InGaP disposed on the InGaAs or GaAs containing layer. 
     
     
         7 . The solar cell module of  claim 1  wherein the secondary optical element is a generally trapezoidal solid with a highly reflective inner surface. 
     
     
         8 . The solar cell module of  claim 1  wherein the optical channel is defined by an optical inlet and an optical outlet, the optical inlet being larger than the optical outlet. 
     
     
         9 . The solar cell module of  claim 8  wherein the optical outlet is sized to have approximately the same dimensions as the solar cell. 
     
     
         10 . The solar cell module of  claim 1  wherein the integral array of Fresnel lenses comprises fourteen Fresnel lenses, the array comprising seven lenses in a first direction and two lenses in a second direction perpendicular to the first direction.