THIN-FILM DEVICES FORMED FROM SOLID GROUP IIIA PARTICLES
Methods and devices are provided for forming thin-films from solid group IIIA-based particles. In one embodiment of the present invention, a method is described comprising of providing a first material comprising an alloy of a) a group IIIA-based material and b) at least one other material. The material may be included in an amount sufficient so that no liquid phase of the alloy is present within the first material in a temperature range between room temperature and a deposition or pre-deposition temperature higher than room temperature, wherein the group IIIA-based material is otherwise liquid in that temperature range. The other material may be a group IA material. A precursor material may be formulated comprising a) particles of the first material and b) 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 thereof. The temperature range described above may be between about 20° C. and about 200° C. It should be understood that the alloy may have a higher melting temperature than a melting temperature of the IIIA-based material in elemental form.
1 . A method comprising:
providing a first material comprising of at least a solid compound of a) a group IIIA-based material and b) a second material comprised of at least one group IA-based material, wherein the second material is included in an amount sufficient so that no liquid phase of the compound is present within the first material in a temperature range between room temperature and a deposition or pre-deposition temperature higher than room temperature, wherein the group IIIA-based material is otherwise liquid in that temperature range.
formulating a precursor material comprising a) particles of the first material and b) 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 thereof.
2 . The method of claim 1 wherein the temperature range is between about 20° C. and about 200° C.
3 . The method of claim 1 wherein the compound has a higher melting temperature than a melting temperature of the IIIA-based material in elemental form.
4 . The method of claim 1 wherein the second material comprises Na.
5 . The method of claim 1 wherein the second material comprises NaF.
6 . The method of claim 1 , wherein the second material contains an element chosen from the group consisting of sodium (Na), potassium (K), lithium (Li), Rubidium (Rb), Cesium (Cs), an alloy containing any of the foregoing, or combinations thereof.
7 . The method of claim 1 wherein the second material comprises an elemental material.
8 . The method of claim 1 wherein the second material comprises a binary alloy.
9 . The method of claim 1 wherein the second material comprises a solid solution.
10 . The method of claim 1 wherein the second material comprises a multinary alloy.
11 . The method of claim 1 wherein the group IIIA-based material of the first material is In.
12 . The method of claim 1 wherein the group IIIA-based material of the first material is Ga.
13 . The method of claim 1 wherein the solid compound comprises a binary alloy.
14 . The method of claim 1 wherein the solid compound comprises a multinary alloy.
15 . The method of claim 1 wherein the solid compound comprises a Ga—Na based alloy.
16 . The method of claim 1 wherein the solid compound contains Ga 4 Na.
17 . The method of claim 1 wherein the solid compound contains Ga 39 Na 22 .
18 . The method of claim 1 wherein the solid compound contains at least about 0.6 weight percent Na.
19 . The method of claim 1 wherein the solid compound contains at least about 8 weight percent Na.
20 . The method of claim 1 wherein the solid compound contains at least about 11 weight percent Na.
21 . The method of claim 1 wherein the solid compound comprises an In—Na based alloy.
22 . The method of claim 1 wherein the solid compound contains In 8 Na 5 .
23 . The method of claim 1 wherein the solid compounds contains a group IB element.
24 . The method of claim 1 wherein the precursor material contains particles comprising Cu-based particles.
25 . The method of claim 1 wherein the precursor material contains particles comprising Cu-based alloy particles.
26 . The method of claim 1 wherein the precursor material contains particles comprising Cu-IIIA based alloy particles.
27 . The method of claim 1 wherein the precursor material contains particles comprising Cu-VIA based alloy particles.
28 . The method of claim 1 wherein the particles are nanoparticles.
29 . The method of claim 1 wherein the particles are spherical nanoparticles.
30 . The method of claim 1 wherein the particles are non-spherical, planar flakes.
31 . The method of claim 1 wherein the solid compound is formed by at least one method selected from the group consisting of: atomization, pyrometallurgy, mechanical alloying, or combinations thereof.
32 . The method of claim 1 wherein the particles are formed using at least one of the following methods: grinding, milling, electroexplosive wire (EEW) processing, evaporation condensation (EC), pulsed plasma processing, or combinations thereof.
33 . The method of claim 1 wherein the particles are formed using at least one of the following methods: spray-pyrolysis, laser pyrolysis, or a bottom-up technique like wet chemical approaches.
34 . The method of claim 1 further comprising using the precursor material in a solution coatable ink for forming a film on a substrate.
35 . The method of claim 1 further comprising:
formulating an ink including the precursor material;
solution depositing the ink onto a substrate to form a precursor layer on the substrate; and
reacting the precursor layer in a suitable atmosphere to form a group IB-IIIA-VIA based film.
36 . The method of claim 1 further comprising:
formulating an ink including the precursor material;
solution depositing the ink onto a substrate to form a precursor layer on the substrate; and
reacting the precursor layer in a suitable atmosphere to form a group IB-IIIA based film.
37 . The method of claim 36 wherein the film includes a group IB-IIIA-VIA compound.
38 . The method of claim 36 wherein the film is a dense film that includes a group IB-IIIA compound.
39 . The method of claim 36 further comprising heating the film in a group VIA based atmosphere to form a group IB-IIIA-VIA compound film.
40 . The method of claim 36 wherein the film comprises a semiconductor film suitable for use as an absorber layer in a photovoltaic device.
41 . The method of claim 36 wherein the film comprises an absorber layer for a solar cell.
42 . The method of claim 36 wherein reacting comprises heating the precursor layer.
43 . The method of claim 36 wherein reacting comprises heating the precursor layer in a group VIA-based atmosphere.
44 . The method of claim 36 wherein the suitable atmosphere contains at least one of the following: selenium, sulfur, tellurium, H2, CO, H2Se, H2S, Ar, N2 or combinations or mixtures thereof.
45 . The method of claim 36 further comprising adding a mixture of one or more elemental or alloy particles containing at least one element selected from the group consisting of: aluminum, tellurium, or sulfur.
46 . The method of claim 36 wherein one or more classes of the particles are doped with one or more inorganic materials.
47 . The method of claim 36 , wherein one or more classes of the particles are doped with one or more inorganic materials chosen from the group consisting of: aluminum (Al) and sulfur (S).
48 . The method of claim 36 , wherein one or more classes of the particles are doped with one or more inorganic materials chosen from the group consisting of: sodium (Na), potassium (K), or lithium (Li).
49 . The method of claim 36 wherein the solid compound containing particles are a sole source of group IIIA elements in the ink.
50 . The method of claim 36 wherein the 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.
51 . The method of claim 36 wherein the film has a Cu/(In+Ga) compositional range of about >1.0 for Cu/(In+Ga) and a Ga/(In+Ga) compositional range of about 0.01 to about 1.0.
52 . The method of claim 36 wherein the 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.
53 . The method of claim 36 wherein the film has a desired Cu/(In+Ga) molar ratio is in the range of about 0.7 to about 1.0 and a desired Ga/(Ga+In) molar ratio in the range of about 0.1 to about 0.8.
54 . The method of claim 36 wherein the ink includes a carrier liquid.
55 . The method of claim 36 wherein depositing comprises using at least one of the following techniques: wet coating, spray coating, spin coating, doctor blade coating, contact printing, top feed reverse printing, bottom feed reverse printing, nozzle feed reverse printing, gravure printing, microgravure printing, reverse microgravure printing, comma direct printing, roller coating, slot die coating, meyerbar coating, lip direct coating, dual lip direct coating, capillary coating, ink-jet printing, jet deposition, spray deposition, or combinations thereof.
56 . The method of claim 1 wherein the material increases the melting temperature and does not contain contaminants that require further heating or chemical treatments to remove contaminants added by the material;
wherein the material is included in an amount sufficient so that no liquid phase of the solid compound is present within the first material in a temperature range between room temperature and a deposition temperature higher than room temperature, wherein the material is otherwise liquid in that temperature range and does not require further heating to remove any materials added by the additive.
57 . A method comprising:
depositing a precursor material on a substrate to form a precursor layer, the precursor material comprising: a) particles of a group IA-IIIA material and b) particles containing at least one element from group IB, IIIA, and/or VIA; and
heating the precursor material in one or more steps to form a photovoltaic absorber layer.
58 . A method comprising:
providing a first material comprising an solid compound of a) a group IIIA-based material and b) at least one group IA-based material, wherein the group IA-based material is included in an amount sufficient so that no liquid phase of the solid compound is present within the first material in a temperature range between room temperature and a deposition temperature higher than room temperature, wherein the group IIIA-based material is otherwise liquid in that temperature range; and
formulating a precursor material comprising a) particles of the first material and b) 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 thereof.
59 . A composition comprising:
a precursor material comprising a) solid particles of a first material comprising an solid compound of a group IIIA-based material and at least one group IA-based material and b) 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 thereof.
wherein the group IA-based material is included in an amount sufficient so that no liquid phase of the solid compound is present within the first material in a temperature range between room temperature and a deposition temperature higher than room temperature, wherein the group IIIA-based material is otherwise liquid in that temperature range.
60 . A method comprising:
providing a first material comprising a solid compound of a) a group IIIA-based material and b) a second material, wherein the second material is included in an amount sufficient so that no liquid phase of the solid compound is present within the first material in a temperature range between room temperature and a deposition temperature higher than room temperature, wherein the group IIIA-based material is otherwise liquid in that temperature range; and
formulating a precursor material comprising a) particles of the first material and b) 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 thereof.
61 . 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 and 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.
62 . A method comprising:
providing a bandgap grading material having an alloy of a) any group IA-based material and b) Ga;
depositing the particles of the alloy over a previously formed Cu—In—Ga—Se based layer;
reacting the particles with the previously formed Cu—In—Ga—Se based layer in a suitable atmosphere at a processing temperature, wherein the bandgap grading material is reacted to form a gallium-rich portion of the Cu—In—Ga—Se based layer at the top of the layer.
63 . The method of claim 62 wherein the group IA-based material comprises an Na-based material.
64 . The method of claim 62 wherein the group IA-based material comprises elemental Na.
65 . The method of claim 62 wherein the alloy comprises a Ga—Na based material.
66 . The method of claim 62 wherein the alloy comprises a Ga—Na—Se based material.