Alignment of optical element and solar cell

Abstract

A system may include a solar cell comprising a first electrical contact, an optical element comprising a second electrical contact, and a solder bump in contact with the first electrical contact and the second electrical contact. The solar cell is to generate charge carriers in response to received photons. Some aspects provide fabrication of a solder bump on an electrical contact of a solar cell, placement of the solder bump in contact with an electrical contact of an optical element, and melting of the solder bump to couple the electrical contact of the solar cell to the electrical contact of the optical element.

1 . A method comprising:
 forming a solder bump on an electrical contact of a solar cell;   placing the solder bump in contact with an electrical contact of an optical element; and   melting the solder bump to couple the electrical contact of the solar cell to the electrical contact of the optical element.   
     
     
         2 . A method according to  claim 1 , wherein melting the solder bump comprises:
 heating the solar cell, solder bump and optical element in a reflow oven.   
     
     
         3 . A method according to  claim 1 , wherein melting comprises:
 melting the solder bump to align an optically active area of the solar cell with a light-emitting interface of the optical element.   
     
     
         4 . A method according to  claim 1 , further comprising:
 depositing transparent underfill material between the solar cell and the optical element and around the solder bump.   
     
     
         5 . A method according to  claim 1 , further comprising:
 coupling a heat paddle to the solar cell.   
     
     
         6 . A method according to  claim 5 , further comprising:
 coupling the heat paddle to a second electrical contact of the optical element; and   encapsulating the heat paddle, the solar cell, the electrical contact of the optical element, and the second electrical contact of the optical element within a polymer.   
     
     
         7 . A method according to  claim 1 ,
 wherein placing the solder bump in contact with the electrical contact of the optical element comprises placing a second solder bump in contact with a second electrical contact of the optical element, and   wherein melting the solder bump to couple the electrical contact of the solar cell to the electrical contact of the optical element comprises melting the second solder bump to couple a second electrical contact of the solar cell to the second electrical contact of the optical element.   
     
     
         8 . An apparatus comprising:
 a solar cell comprising a first electrical contact, the solar cell to generate charge carriers in response to received photons;   an optical element comprising a second electrical contact; and   a solder bump in contact with the first electrical contact and the second electrical contact.   
     
     
         9 . An apparatus according to  claim 8 , wherein the solder bump has been reflowed while in contact with the first electrical contact and the second electrical contact. 
     
     
         10 . An apparatus according to  claim 8 , wherein the first electrical contact comprises:
 a conductive contact;   a barrier layer in contact with the conductive contact; and   a solder pad in contact with the barrier layer.   
     
     
         11 . An apparatus according to  claim 8 , further comprising:
 transparent underfill material disposed between the solar cell and the optical element and around the solder bump.   
     
     
         12 . An apparatus according to  claim 11 , wherein the solar cell comprises an anti-reflective coating exhibiting an index of refraction substantially equal to an index of refraction exhibited by the transparent underfill material. 
     
     
         13 . An apparatus according to  claim 8 , wherein the solar cell comprises an anti-reflective coating exhibiting an index of refraction substantially equal to 1.0. 
     
     
         14 . An apparatus according to  claim 8 , wherein the solar cell comprises an optically-active area,
 wherein the optical element comprises a light-emitting interface, and   wherein the optically-active area is aligned with the light-emitting interface.   
     
     
         15 . An apparatus according to  claim 8 , wherein the solar cell comprises:
 a semiconductor substrate comprising a majority of a first type of charge carrier;   a first semiconductor portion comprising a majority of a second type of charge carrier;   a semiconductor layer disposed between the semiconductor substrate and the first semiconductor portion to generate charge carriers of the first type and of the second type in response to received photons; and   a third electrical contact in contact with the semiconductor substrate and to receive charge carriers of the second type generated by the semiconductor layer,   wherein the first semiconductor portion is disposed between the first electrical contact and the semiconductor layer.   
     
     
         16 . An apparatus according to  claim 8 , wherein the solar cell comprises a third electrical contact and wherein the optical element comprises a fourth electrical contact, the apparatus further comprising:
 a second solder bump in contact with the third electrical contact and the fourth electrical contact.   
     
     
         17 . An apparatus according to  claim 8 , wherein the solar cell comprises a heat paddle and wherein the optical element comprises a third electrical contact electrically coupled to the heat paddle, the apparatus further comprising:
 a polymer encapsulating the heat paddle, the solar cell, the second electrical contact, and the third electrical contact.   
     
     
         19 . An apparatus according to  claim 8 , wherein the optical element comprises a solar concentrator. 
     
     
         20 . A method comprising:
 forming a solder bump on an electrical contact of an optical element;   placing the solder bump in contact with an electrical contact of a solar cell; and   melting the solder bump to couple the electrical contact of the solar cell to the electrical contact of the optical element.   
     
     
         21 . A method according to  claim 20 , wherein melting the solder bump comprises:
 heating the solar cell, solder bump and optical element in a reflow oven.   
     
     
         22 . A method according to  claim 20 , wherein melting comprises:
 melting the solder bump to align an optically active area of the solar cell with a light-emitting interface of the optical element.   
     
     
         23 . A method according to  claim 20 , further comprising:
 depositing transparent underfill material between the solar cell and the optical element and around the solder bump.   
     
     
         24 . A method according to  claim 20 ,
 wherein placing the solder bump in contact with the electrical contact of the solar cell comprises placing a second solder bump in contact with a second electrical contact of the solar cell, and   wherein melting the solder bump to couple the electrical contact of the solar cell to the electrical contact of the optical element comprises melting the second solder bump to couple the second electrical contact of the solar cell to a second electrical contact of the optical element.