Photovoltaic device

Abstract

The present invention is related to a photovoltaic device, the device comprising a first layer of a first semiconductor material of a first conductivity type, a second layer of a second semiconductor material of the opposite conductivity type of the first layer, and a third layer of a third porous semiconductor material situated between the first layer and the second layer. The present invention also provides a method for producing the photovoltaic device.

1 . A photovoltaic device, the device comprising:
 a first layer comprising an amorphous silicon semiconductor material of n-type conductivity;   a second layer comprising a crystalline silicon semiconductor material of p-type conductivity; and   a third layer comprising a non-doped semiconductor material, wherein the third layer is situated between and contacts the first layer and the second layer, and wherein the third layer is a translucent porous layer and diffusion barrier having a thickness of from about 1 nm to about 50 nm.   
     
     
         2 . The photovoltaic device of  claim 1 , wherein the photovoltaic device comprises a device selected from the group consisting of a photodiode, a photoresistor, and a solar cell. 
     
     
         3 . The photovoltaic device of  claim 1 , wherein the third semiconductor material comprises a crystalline semiconductor material. 
     
     
         4 . The photovoltaic device of  claim 1 , wherein the third layer comprises a material selected from the group consisting of a multicrystalline semiconductor material and a monocrystalline semiconductor material. 
     
     
         5 . The photovoltaic device of  claim 1 , wherein the second layer comprises a monocrystalline semiconductor material. 
     
     
         6 . The photovoltaic device of  claim 1 , wherein the second layer comprises a multicrystalline semiconductor material. 
     
     
         7 . The photovoltaic device of  claim 1 , wherein the first layer has a thickness of from about 3 nm to about 100 nm. 
     
     
         8 . The photovoltaic device of  claim 1 , further comprising a fourth layer, wherein the second layer is attached to the fourth layer, wherein the fourth layer comprises a porous layer comprising a fourth semiconductor material, and wherein the fourth semiconductor material comprises non-doped crystalline silicon semiconductor material. 
     
     
         9 . The photovoltaic device of  claim 1 , wherein the second layer comprises a plurality of macro etch pits having a diameter of greater than about one micron, and wherein a portion of the macro etch pits comprise a plurality of fine etch pits having a diameter of less than about one micron. 
     
     
         10 . The photovoltaic device of  claim 1 , wherein the third layer comprises a porous semiconductor material comprising a semiconductor material and voids, wherein a percentage of a total volume occupied by voids is from 10% to 85%. 
     
     
         11 . The photovoltaic device of  claim 1 , wherein the third layer consists of a porous non-doped monocrystalline silicon semiconductor material. 
     
     
         12 . The photovoltaic device of  claim 1 , wherein the third layer consists of a porous non-doped multicrystalline silicon semiconductor material. 
     
     
         13 . The photovoltaic device of  claim 1 , wherein the third layer consists of a porous layer. 
     
     
         14 . The photovoltaic device of  claim 1 , wherein the third layer consists of a translucent layer. 
     
     
         15 . The photovoltaic device of  claim 1 , wherein the third layer consists of a porous translucent layer that acts as a diffusion barrier. 
     
     
         16 . The photovoltaic device of  claim 1 , wherein the third layer comprises a porous layer of high transparency. 
     
     
         17 . The photovoltaic device of  claim 1 , wherein the third layer consists of a transparent porous layer. 
     
     
         18 . The photovoltaic device of  claim 1 , wherein the third layer consists of silicon. 
     
     
         19 . The photovoltaic device of  claim 1 , wherein the third layer consists of germanium. 
     
     
         20 . The photovoltaic device of  claim 1 , wherein the third layer consists of carbon. 
     
     
         21 . The photovoltaic device of  claim 1 , wherein the third layer is a single translucent porous layer. 
     
     
         22 . The photovoltaic device of  claim 1 , wherein the third layer consists of a single semiconductor element. 
     
     
         23 . The photovoltaic device of  claim 1 , wherein the third layer comprises silicon. 
     
     
         24 . The photovoltaic device of  claim 1 , wherein the third layer comprises germanium. 
     
     
         25 . The photovoltaic device of  claim 1 , wherein the first layer, the second layer, and the third layer together constitute a heterojunction with intrinsic thin-layer cell. 
     
     
         26 . The photovoltaic device of  claim 1 , wherein the first layer consists of an amorphous silicon semiconductor material of n-type conductivity, wherein the second layer consists of a crystalline silicon semiconductor material of p-type conductivity; and wherein the third layer consists of a porous, translucent semiconductor material. 
     
     
         27 . The photovoltaic device of  claim 1 , wherein the third layer has a porosity of from 15% to 20% and a thickness of from 5 nm to 10 nm as measured by spectroscopic ellipsometry.