Method for manufacturing and scribing a thin-film solar cell

Abstract

A method for manufacturing a thin-film solar cell includes providing a first conducting layer on a substrate that has an area at least 0.75 m 2 . The first conducting layer is located in a deposition portion of the area. An ultraviolet laser beam is applied through a lens to the first conducting layer. Portions of the first conducting layer are scribed form a trench through the layer. The lens focuses the beam and has a focal length at least 100 mm. The focused beam includes an effective portion effective for the scribing and an ineffective portion ineffective for the scribing. The substrate sags and the first conducting layer remains in the effective portion of the focused beam across the area during the step of applying. One or more active layers are provided on the first conducting layer. A second conducting layer is provided on the one or more active layers.

What is claimed is: 
     
         1 . A laser scribing apparatus for forming a thin-film solar cell, comprising:
 a support device adapted to support a solar cell substrate that has an area of at least 0.75 m 2  and a conducting layer including ZnO located on the substrate in a deposition portion of said area; and   a selectively positionable ultraviolet laser that generates a beam having a wavelength of less than 400 nm and that includes a lens having a focal length of at least 100 mm for focusing the beam, wherein the selectively positionable ultraviolet laser is selectively positionable with respect to the substrate,   wherein the lens focuses the beam onto the conducting layer such that the beam scribes portions of the conducting layer through to the substrate to form a trench through the conducting layer,   wherein the beam includes an effective portion that is effective for scribing the portions of the conducting layer and an ineffective portion that is ineffective for scribing the portions of the conducting layer, and   wherein the substrate sags when supported by the support device such that the portions of the conducting layer that are scribed by the beam are located within the effective portion of the beam when scribed.   
     
     
         2 . The laser scribing apparatus of  claim 1 , wherein the laser is located at a distance from the support device and the distance remains substantially constant while the beam is focused onto the conducting layer. 
     
     
         3 . The laser scribing apparatus of  claim 2 , wherein the laser scribing apparatus includes a processor for executing a scribing program and controlling movements of the laser based on a predetermined scribing route. 
     
     
         4 . The laser scribing apparatus of  claim 3 , wherein the wavelength is about 355 nm. 
     
     
         5 . The laser scribing apparatus of  claim 4 , wherein the focal length is not greater than 150 nm. 
     
     
         6 . The laser scribing apparatus of  claim 5 , wherein the trench has a width of at least 20 μm and includes substantially smooth trench walls.