Solid Group IIIA Particles Formed Via Quenching

Abstract

Methods and devices are provided for forming thin-films from solid group IIIA-based particles. In one embodiment, a process for forming solid particles is provided. The method includes providing a first suspension of solid and/or liquid particles containing at least one group IIIA element. A material may be added to substantially increase the melting point of at least one set of group IIIA-containing particles in the suspension into higher-melting solid particles comprising an alloy of the group IIIA element and at least a part of the added material. The suspension may be deposited onto a substrate to form a precursor layer on the substrate and the precursor layer is reacted in a suitable atmosphere to form a film.

1 . A process comprising:
 providing a first suspension of liquid particles containing at least one group III element;   adding a liquid group IA material to the first suspension to solidify a binary alloy of group IIIA and IA material out of at least part of an original material in the first suspension to form nanoparticles of group IA-IIIA of a size smaller than the liquid particles of group IIIA element in the first suspension;   depositing the suspension of solid group IA-IIIA nanoparticles with group IB and IIIA material onto a substrate to form a precursor layer on the substrate; and   reacting the precursor layer in a suitable atmosphere to form a film.   
     
     
         2 . The process of  claim 1  wherein the alloy has a higher melting temperature than a melting temperature of the IIIA element. 
     
     
         3 . The process of  claim 1  wherein the solid and/or liquid particles contain at least one element from the group consisting of: group IB, IIIA, VIA element, alloys containing any of the foregoing elements, or combinations. 
     
     
         4 . The process of  claim 1  further comprising providing a second suspension of solid and/or liquid particles containing at least one element from the group consisting of: group IB, IIIA, VIA element, alloys containing any of the foregoing elements, or combinations 
     
     
         5 . The process of  claim 1  wherein adding the material creates solid particles of the material and the group IIIA element. 
     
     
         6 . The process of  claim 1  further comprising separately preparing the first suspension before mixing it with a second suspension. 
     
     
         7 . The process of  claim 1  further comprising separately preparing a IIIA-alloy-solid-particles-based suspension before mixing it with other IB and/or IIIA and/or VIA elements. 
     
     
         8 . The process of  claim 1  comprising separate emulsion/suspension creation step before adding it to a mixed final suspension and depositing the suspension onto a substrate to form a precursor layer on the substrate. 
     
     
         9 . The process of  claim 1  wherein at least one set of the solid particles are group IIIA-Na alloy containing particles, wherein Na in the group IIIA-Na alloy containing particles is at an amount sufficient so that no liquid phase of a group IIIA-Na alloy is present within the group IIIA-Na alloy containing particles in a temperature range between room temperature and a process temperature higher than room temperature, wherein the group IIIA based material is otherwise liquid in that temperature range. 
     
     
         10 . The process of  claim 1  wherein at least one set of the solid particles are group IIIA-Na alloy containing particles, wherein Na in the group IIIA-Na alloy containing particles is at an amount sufficient so that no liquid phase of a group MA-Na alloy is present within the group IIIA-Na alloy containing particles in a temperature range between about 15 C and about 500 C, wherein the group IIIA-based material is otherwise liquid in that temperature range. 
     
     
         11 . The process of  claim 1  wherein at least one set of the solid particles are group IIIA-Na alloy containing particles, wherein Na in the group IIIA-Na alloy containing particles is at an amount sufficient so that no liquid phase of a group IIIA-Na alloy is present within the group IIIA-Na alloy containing particles at a deposition and/or dispersion temperature. 
     
     
         12 . The process of  claim 1  wherein depositing comprises solution depositing the suspension. 
     
     
         13 . The process of  claim 1  wherein the material comprises elemental sodium. 
     
     
         14 . The process of  claim 1  wherein the material comprises a sodium-based material. 
     
     
         15 . The process of  claim 1  wherein the material comprises a sodium-based material. 
     
     
         16 . The process of  claim 1  wherein the adding step comprises adding an emulsion of the material to an emulsion containing a liquid group IIIA element to create the solid particles. 
     
     
         17 . The process of  claim 1  wherein the adding step comprises adding an emulsion of the material to dispersion of solid group IIIA element to create the solid particles. 
     
     
         18 . The process of  claim 1  wherein the adding step comprises adding a dispersion of solid particles of the material to an emulsion containing a liquid group IIIA element to create the solid particles. 
     
     
         19 . The process of  claim 1  wherein the adding step comprises adding a dispersion of solid particles of the material to a dispersion of solid particle containing a group IIIA element for a solid-solid reaction to create solid particles. 
     
     
         20 . The process of  claim 1  further comprising milling the material and the one set of group IIIA-containing liquid particles in the suspension to more thoroughly mix solids with the liquid. 
     
     
         21 . The process of  claim 1  further comprising mechanically alloying the material and the one set of group IIIA-containing particles in the suspension to more thoroughly mix solids. 
     
     
         22 . The process of  claim 1  wherein adding the material creates particles of sizes smaller than the size of the group IIIA-containing particles found in the suspension prior to introduction of the material. 
     
     
         23 . The process of  claim 1  further comprising agitating the suspension to mix and size reduce the particles. 
     
     
         24 . The process of  claim 1  further comprising sonicating the suspension to mix and size reduce the particles. 
     
     
         25 . The process of  claim 1  further comprising using electromagnetic size-reduction/control to mix and size reduce the particles. 
     
     
         26 . The process of  claim 1  further comprising adding any sodium containing particles during emulsification to solidify droplets of Ga to form solid Ga—Na particles. 
     
     
         27 . The process of  claim 1  further comprising adding sodium in elemental form prior to, during, or after emulsification to solidify droplets of Ga to form solid Ga—Na particles. 
     
     
         28 . The process of  claim 1  further comprising adding liquid sodium in elemental form prior to, during, or after emulsification to solidify droplets of Ga to form solid Ga—Na particles. 
     
     
         29 . The process of  claim 1  further comprising combining a sodium emulsion with a gallium emulsion to solidify droplets of Ga to form solid Ga—Na particles. 
     
     
         30 . The process of  claim 1  further comprising combining a sodium emulsion with a gallium emulsion by milling to solidify droplets of Ga to form solid Ga—Na particles. 
     
     
         31 . The process of  claim 1  further comprising combining a sodium emulsion with a solid gallium particles by mechanical alloying at temperatures below the melting point of gallium to form solid. Ga—Na particles. 
     
     
         32 . The process of  claim 1  further comprising combining a sodium dispersion with a gallium dispersion by mechanical alloying to solidify droplets of Ga to form solid Ga—Na particles. 
     
     
         33 . The process of  claim 1  wherein the film includes a group IB-IIIA-VIA compound. 
     
     
         34 . The process of  claim 1  wherein reacting comprises heating the layer in a suitable atmosphere. 
     
     
         35 . The process of  claim 1  wherein at least one set of the particles in the suspension is in the form of nanoglobules. 
     
     
         36 . The process of  claim 1  wherein at least one set of the particles in the suspension are in the form of nanoglobules and contain at least one group IIIA element. 
     
     
         37 . The process of  claim 1  wherein at least one set of the particles in the suspension is in the form of nanoglobules comprising of a group IIIA element in elemental form. 
     
     
         38 . The process of  claim 1  wherein at least some of the particles have a platelet shape. 
     
     
         39 . The process of  claim 1  wherein a majority of the particles have a platelet shape. 
     
     
         40 . The process of  claim 1  wherein all of the particles have a platelet shape. 
     
     
         41 . The process of  claim 1  wherein the depositing step comprises coating the substrate with the suspension. 
     
     
         42 . The process of  claim 1  wherein the suspension comprises an emulsion. 
     
     
         43 . The process of  claim 1  wherein gallium is incorporated as a group IIIA element in the form of a suspension of nanoglobules. 
     
     
         44 . The process of  claim 43  wherein nanoglobules of gallium are formed by creating an emulsion of liquid gallium in a solution. 
     
     
         45 . The process of  claim 43  further comprising maintaining or enhancing a suspension of liquid gallium in solution by stirring, mechanical means, electromagnetic means, ultrasonic means, and/or the addition of dispersants and/or emulsifiers. 
     
     
         46 . The process of  claim 1  further comprising adding a mixture of one or more elemental particles selected from: aluminum, tellurium, or sulfur. 
     
     
         47 . The process of  claim 1  wherein the suitable atmosphere contains at least one of the following: selenium, sulfur, tellurium, H 2 , CO, H 2 Se, H 2 S, Ar, N 2  or combinations or mixture thereof. 
     
     
         48 . The process of  claim 1  wherein one or more classes of the particles are doped with one or more inorganic materials. 
     
     
         49 . The process of  claim 1 , wherein one or more classes of the particles are doped with one or more inorganic materials chosen from the group consisting of: aluminum (Al), sulfur (S), sodium (Na), potassium (K), lithium (Li), alloys containing the foregoing elements, or combinations thereof. 
     
     
         50 . The process of  claim 1  wherein the particles are nanoparticles. 
     
     
         51 . The process of  claim 1  further comprising forming the particles from a feedstock by one of the following processes: milling, electroexplosive wire (EEW) processing, evaporation condensation (EC), pulsed plasma processing, or combinations thereof. 
     
     
         52 . The process of  claim 1  wherein the material does negatively impact the resulting absorber layer and does not need to be removed from the resulting absorber layer. 
     
     
         53 . The process of  claim 1  wherein the material comprises Al to make solid Al—Ga particles. 
     
     
         54 . The process of  claim 1  wherein the material comprises Al; wherein Ga dissolves in Al to make solid Al—Ga particles for use in forming a film of CAGS and/or CAIGS.