Formation of a transparent conductive oxide film for use in a photovoltaic structure

Abstract

A process for producing a photovoltaic structure that includes a thin coating film, generally made of a transparent conductive oxide, deposited on top of a sublayer having photovoltaic properties. The coating film is deposited electrochemically in an electrolysis bath and at least partly assisted by illumination coming from a light source.

1 . A process for producing a photovoltaic structure, said structure comprising a thin coating film deposited on top of a sublayer having photovoltaic properties, wherein the coating film is deposited electrochemically, the deposition being at least partly assisted by illumination coming from a light source. 
     
     
         2 . The process as claimed in  claim 1 , wherein the illumination of the photovoltaic sublayer causes an electrical effect conducive to uniform and homogeneous deposition of the coating film, at least at the start of growth of the coating film. 
     
     
         3 . The process as claimed in  claim 1 , wherein the coating film is based on a transparent oxide and the coating film is intended to act as at least one of transparent and conductive window of a photovoltaic cell. 
     
     
         4 . The process as claimed in  claim 3 , wherein the coating film is based on zinc oxide. 
     
     
         5 . The process as claimed in  claim 4 , wherein the film is deposited by electrolysis with zinc ions dissolved in an electrolysis bath, by a cathodic reaction. 
     
     
         6 . The process as claimed in  claim 5 , wherein the cathodic reaction is performed with addition of an oxygen donor element taken from at least one of oxygen, hydrogen peroxide and nitrates. 
     
     
         7 . The process as claimed in  claim 1 , wherein the coating film is made conductive by doping with at least one element introduced in solution, taken from chlorine, fluorine, iodine, bromine, gallium, indium, boron and aluminum. 
     
     
         8 . The process as claimed in  claim 1 , wherein the illumination is within the spectral range between 100 and 1500 nm and with an incident power between 0.1 mW/cm 2  and 1 W/cm 2 . 
     
     
         9 . The process as claimed in  claim 1 , wherein the photovoltaic sublayer consists of a I-III-VI 2  alloy of the Cu(In,Ga,Al)(S,Se) 2  type. 
     
     
         10 . The process as claimed in  claim 1 , wherein the coating film is deposited directly on the photovoltaic sublayer. 
     
     
         11 . The process as claimed in  claim 1 , wherein the coating film is deposited on at least one interface film located above the photovoltaic sublayer. 
     
     
         12 . The process as claimed in  claim 11 , wherein the interface film is a film based on cadmium sulfide. 
     
     
         13 . The process as claimed in  claim 11 , wherein the interface film is a film based on zinc sulfide. 
     
     
         14 . The process as claimed in  claim 11 , wherein the interface film is a film based on indium sulfide or gallium sulfide. 
     
     
         15 . The process as claimed in  claim 12 , wherein the interface film is covered with a film of undoped zinc oxide or an undoped zinc oxide alloy. 
     
     
         16 . The process as claimed in  claim 1 , wherein the coating film is deposited electrochemically at a temperature in the 50° C. to 150° C. range. 
     
     
         17 . A facility for implementing the process as claimed in  claim 1 , comprising an electrolysis bath and a light source illuminating the photovoltaic film.