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 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.