Solar cells

Abstract

A solar cell is provided. The solar cell includes a silicon substrate, a back electrode, a doped silicon layer, and an upper electrode. The silicon substrate includes a first surface, a second surface, and a number of three-dimensional nano-structures located on the first surface. The three-dimensional nano-structures are located on the second surface. The three-dimensional nano-structures are linear protruding structures that are spaced from each other, and a cross section of each linear protruding structure is an arc. The doped silicon layer is attached to the three-dimensional nano-structures and the second surface between the three-dimensional nano-structures.

What is claimed is: 
     
         1 . A solar cell, comprising:
 a silicon substrate comprising a first surface, a second surface, and a plurality of three-dimensional nano-structures located on the second surface; wherein the plurality of three-dimensional nano-structures are linear protruding structures that are spaced from each other, and a cross section of each linear protruding structure is an arc;   a back electrode located on and Ohmic connected to the first surface of the silicon substrate;   a doped silicon layer attached to the plurality of three-dimensional nano-structures and covering the second surface of the silicon substrate that is between the plurality of three-dimensional nano-structures; and   an upper electrode located on at least part of the doped silicon layer.   
     
     
         2 . The solar cell of  claim 1 , wherein the plurality of three-dimensional nano-structures are uniformly distributed on the second surface to form an array. 
     
     
         3 . The solar cell of  claim 2 , wherein the plurality of three-dimensional nano-structures in the array are substantially equidistantly arranged, concentric circularly arranged, or concentric rectangle arranged. 
     
     
         4 . The solar cell of  claim 1 , wherein the plurality of three-dimensional nano-structures are arranged along a straight line, a curvy line, or a polygonal line. 
     
     
         5 . The solar cell of  claim 1 , wherein a height of the arc ranges from about 100 nanometers to about 500 nanometers, and a width of the arc ranges from about 200 nanometers to about 1000 nanometers. 
     
     
         6 . The solar cell of  claim 5 , wherein a distance between adjacent three-dimensional nano-structures ranges is in a range from about 10 nanometers to about 1000 nanometers. 
     
     
         7 . The solar cell of  claim 1 , wherein a height of the arc ranges from about 150 nanometers to about 200 nanometers, and a width of the arc ranges from about 300 nanometers to about 400 nanometers. 
     
     
         8 . The solar cell of  claim 7 , wherein a distance between adjacent three-dimensional nano-structures ranges from about 100 nanometers to about 200 nanometers. 
     
     
         9 . The solar cell of  claim 1 , further comprising an intrinsic layer, and the intrinsic layer is located between the silicon substrate and the doped silicon layer. 
     
     
         10 . The solar cell of  claim 1 , further comprising a metal layer attached on an outer surface of the doped silicon layer. 
     
     
         11 . The solar cell of  claim 12 , wherein a thickness of the metal layer ranges from about 2 nanometers to about 200 nanometers. 
     
     
         12 . The solar cell of  claim 1 , wherein the upper electrode comprises a first part and a second part, the first part is suspended over the doped silicon layer, and the second part is in contact with the doped silicon layer. 
     
     
         13 . The solar cell of  claim 1 , wherein the upper electrode is attached to the entire surface of the doped silicon layer away from the silicon substrate. 
     
     
         14 . A solar cell, comprising:
 a silicon substrate comprising a body and a plurality of three-dimensional nano-structures, wherein the body comprises a first surface and a second surface, the plurality of three-dimensional nano-structures are located on the second surface and spaced from each other; the plurality of three-dimensional nano-structures are linear protruding structures, and a cross section of each linear protruding structure is an semicircle;   a back electrode located on and Ohmic connected to the first surface of the silicon substrate;   a doped silicon layer attached to the plurality of three-dimensional nano-structures and covering the second surface that is between the plurality of three-dimensional nano-structures; and   an upper electrode located on at least part of the doped silicon layer.   
     
     
         15 . The solar cell of  claim 16 , wherein the body and the plurality of three-dimensional nano-structures are an integrated structure. 
     
     
         16 . The solar cell of  claim 16 , wherein the plurality of three-dimensional nano-structures is substantially equidistantly arranged and arranged along a same direction. 
     
     
         17 . The solar cell of  claim 16 , wherein a diameter of each semicircle linear protruding structure ranges from about 300 nanometers to about 400. 
     
     
         18 . The solar cell of  claim 16 , wherein a distance between adjacent three-dimensional nano-structures ranges from about 100 nanometers to about 200 nanometers.