Metallic Dispersion

Abstract

A compound film may be formed by formulating a mixture of elemental nanoparticles composed of the Ib, the IIIa, and, optionally, the VIa group of elements having a controlled overall composition. The nanoparticle mixture is combined with a suspension of nanoglobules of gallium to form a dispersion. The dispersion may be deposited onto a substrate to form a layer on the substrate. The layer may then be reacted in a suitable atmosphere to form the compound film. The compound film may be used as a light-absorbing layer in a photovoltaic device.

1 . A semiconductor film made by a process comprising:
 formulating a dispersion of nanoparticles of the Ib, the IIIa, and, optionally, the VIa group of elements, depositing said dispersion onto a substrate to form a layer on the substrate, and reacting the layer in a suitable atmosphere to form said compound film, wherein said compound film has a Cu/(In+Ga) compositional range of about 0.01 to about 1.0 and a Ga/(In+Ga) compositional range of about 0.01 to about 1.0.   
   
   
       2 . A photovoltaic device having a light-absorbing layer containing elements of groups Ib, IIIa and VIa, wherein the light-absorbing layer is formed from a compound film deposited on a substrate by the process of  claim 1 . 
   
   
       3 . The process of  claim 1 , wherein said nanoparticles are solid-particulates. 
   
   
       4 . The process of  claim 1 , wherein said dispersion nanoparticles includes at least one element from the group consisting of: aluminum, tellurium, or sulfur. 
   
   
       5 . The process of  claim 1 , wherein one or more classes of said nanoparticles are doped with one or more inorganic materials. 
   
   
       6 . The process of  claim 5 , wherein the inorganic materials are chosen from the group of aluminum (Al), sulfur (S), sodium (Na), potassium (K), or lithium (Li). 
   
   
       7 . The process of  claim 1  wherein depositing includes using at least one method from the group consisting of: dip coating, spin coating, web coating, doctor blade coating, cup coating, spray coating, printing, microgravure, reverse microgravure, comma, slot/die coating, lip coating, and the like. 
   
   
       8 . The process of  claim 1  wherein the substrate is flexible. 
   
   
       9 . The process of  claim 1  wherein e substrate is a plastic foil, or a metallized plastic foil. 
   
   
       10 . The process of  claim 9  wherein the substrate is selected from the group consisting of: stainless steel, Al, Mo, and Ti. 
   
   
       11 . The process of  claim 9  further comprising a contact layer comprised of a different metal than the substrate and disposed between the substrate and the film. 
   
   
       12 . The process of  claim 9  wherein the contact layer comprises molybdenum. 
   
   
       13 . The process of  claim 9  further comprising depositing a window layer on the semiconductor film. 
   
   
       14 . The process of  claim 13  wherein the window layer comprises of a material selected from the group consisting of: cadmium sulfide (CdS), zinc sulfide (ZnS), zinc hydroxide, zinc selenide (ZnSe), n-type organic materials, or some combination of two or more of these or similar materials. 
   
   
       15 . The process of  claim 1  wherein reacting occurs during the annealing step. 
   
   
       16 . The process of  claim 1  wherein reacting occurs after the annealing step. 
   
   
       17 . The process of  claim 1  wherein reacting occurs in a suitable atmosphere that contains at least one from the group consisting of: selenium, sulfur, or tellurium, and/or hydride gases comprising Se and/or S and/or Te, or mixtures of these gases.