Thin Film Solar Cell Module Including Series Connected Cells Formed on a Flexible Substrate by Using Lithography

Abstract

Solar thin film modules are provided with reduced lateral dimensions of isolation trenches and contact trenches, which provide for a series connection of the individual solar cells. To this end lithography and etch techniques are applied to pattern the individual material layers, thereby reducing parasitic shunt leakages compared to conventional laser scribing techniques. In particular, there may be series connected solar cells formed on a flexible substrate material that are highly efficient in indoor applications.

What is claimed is: 
     
         1 . A solar cell module comprising:
 a flexible substrate;   a non-transparent conductive layer having a plurality of first isolation trenches and a plurality of first contact trenches, a width of one of the plurality of first contact trenches being less than a width of a corresponding one of the plurality of first isolation trenches;   a semiconductor layer having a plurality of second isolation trenches and a plurality of second contact trenches, the plurality of second isolation trenches being aligned with the plurality of first isolation trenches, and the plurality of second contact trenches being aligned with the plurality of first contact trenches to laterally divide the semiconductor layer into a plurality of semiconductor regions; and   a plurality of dielectric sidewall spacers covering each sidewall of the first isolation trenches and each sidewall of the second isolation trenches.   
     
     
         2 . The solar cell module of  claim 1 , further comprising a second conductive layer having a plurality of third isolation trenches separating adjacent cells of a plurality of series-connected solar cells of the solar cell module. 
     
     
         3 . The solar cell module of  claim 2 , wherein each of the plurality of first, second, and third isolation trenches, and each of the plurality of first and second contact trenches has a width less than 10 μm. 
     
     
         4 . The solar cell module of  claim 1 , wherein the semiconductor layer comprises amorphous hydrogenated silicon. 
     
     
         5 . The solar cell module of  claim 1 , wherein the flexible substrate comprises a polyimide, a polyethylene-naphthalate (PEN), or a polyethylene-terephthalate (PET) material. 
     
     
         6 . The solar cell module of  claim 1 , wherein the semiconductor layer is a p-i-n semiconductor layer comprising a p-type semiconductor layer, an n-type semiconductor layer, and an intrinsic semiconductor layer. 
     
     
         7 . The solar cell module of  claim 1 , wherein the semiconductor layer is a p-n semiconductor layer comprising a p-type semiconductor layer and an n-type semiconductor layer. 
     
     
         8 . A solar cell module comprising:
 a flexible substrate having an exposed surface configured to be mounted to a first carrier material and having a second major surface opposite the exposed surface;   a metallization layer disposed on the second major surface of the flexible substrate;   a semiconductor layer disposed on the metallization layer, the semiconductor layer having a first major surface and an opposite second major surface facing the flexible substrate;   a plurality of isolation trenches in the metallization layer and the semiconductor layer;   a plurality of contact trenches in the metallization layer and the semiconductor layer laterally dividing the semiconductor layer into a plurality of semiconductor regions, a width of a contact trench being less than a width of an isolation trench;   a plurality of dielectric sidewall spacers covering each sidewall of the isolation trenches; and   a transparent metallization layer disposed on the plurality of semiconductor regions, within the plurality of isolation trenches, the plurality of dielectric sidewall spacers, and the plurality of contact trenches.   
     
     
         9 . The solar cell module of  claim 8 , where an exposed surface opposite the first major surface of the transparent metallization layer is configured to be a light incident surface of the solar cell module. 
     
     
         10 . The solar cell module of  claim 8 , wherein a plurality of second isolation trenches in the transparent metallization layer is configured to separate adjacent cells of a plurality of series-connected solar cells. 
     
     
         11 . The solar cell module of  claim 8 , wherein the semiconductor layer comprises amorphous hydrogenated silicon. 
     
     
         12 . The solar cell module of  claim 8 , wherein the flexible substrate comprises a polyimide, a polyethylene-naphthalate (PEN), or a polyethylene-terephthalate (PET) material. 
     
     
         13 . The solar cell module of  claim 8 , wherein the semiconductor layer is a p-i-n semiconductor layer comprising a p-type semiconductor layer, an n-type semiconductor layer, and an intrinsic semiconductor layer. 
     
     
         14 . The solar cell module of  claim 8 , wherein the semiconductor layer is a p-n semiconductor layer comprising a p-type semiconductor layer and an n-type semiconductor layer. 
     
     
         15 . A solar cell module comprising:
 a flexible substrate;   a metallization layer disposed on the flexible substrate and comprising a major surface;   a plurality of first isolation trenches in the metallization layer;   a semiconductor layer disposed over the major surface of the metallization layer;   a plurality of contact trenches in the semiconductor layer laterally dividing the semiconductor layer into a plurality of semiconductor regions;   a transparent metallization layer disposed on the plurality of semiconductor regions, the transparent metallization layer comprising a first contact region that physically contacts a first portion of the major surface and a second contact region that physically contacts a second portion of the major surface; and   a plurality of second isolation trenches disposed in the transparent metallization layer and the semiconductor layer, the plurality of second isolation trenches separating adjacent cells of a plurality of series-connected solar cells, and the plurality of second isolation trenches isolating the first contact region and the second contact region from sidewalls of the plurality of semiconductor regions facing the corresponding first and second contact regions.   
     
     
         16 . The solar cell module of  claim 15 , wherein the transparent metallization layer includes an exposed surface opposite the metallization layer and configured to be a light incident surface of the solar cell module. 
     
     
         17 . The solar cell module of  claim 15 , wherein the flexible substrate comprises a polyimide, a polyethylene-naphthalate (PEN), or a polyethylene-terephthalate (PET) material. 
     
     
         18 . The solar cell module of  claim 15 , wherein the semiconductor layer comprises amorphous hydrogenated silicon. 
     
     
         19 . The solar cell module of  claim 15 , wherein the semiconductor layer is a p-i-n semiconductor layer comprising a p-type semiconductor layer, an n-type semiconductor layer, and an intrinsic semiconductor layer. 
     
     
         20 . The solar cell module of  claim 15 , wherein the semiconductor layer is a p-n semiconductor layer comprising a p-type semiconductor layer and an n-type semiconductor layer.