SOLID GROUP IIIA PARTICLES FORMED VIA QUENCHING
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 solid and/or liquid particles containing at least one group IIIA element;
adding a material to solidify create an alloy out of at least part of the original material where any previous room temperature liquid components are frozen at significantly higher temperatures than the original material and the group IIIA element found in the liquid particles;
depositing the suspension 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 the 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 the 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 IIIA-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 liquid sodium.
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.
The process of claim 1 further comprising using high pressure homogenization to mix.
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 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.