High-throughput printing of nanostructured semiconductor precursor layer
Materials and devices are provided for high-throughput printing of nanostructured semiconductor precursor layer. In one embodiment, a material is provided that comprises of a plurality of microflakes having a material composition containing at least one element from Groups IB, IIIA, and/or VIA. The microflakes may be created by milling precursor particles characterized by a precursor composition that provides sufficient malleability to form a planar shape from a non-planar starting shape when milled, and wherein overall amounts of elements from Groups IB, IIIA and/or VIA contained in the precursor particles combined are at a desired stoichiometric ratio of the elements. It should also be understood that other flakes such as but not limited to nanoflakes may also be used to form the precursor material.
1 . A material comprising:
a plurality of microflakes having a material composition containing at least one element from Groups IB, IIIA, and/or VIA;
wherein the microflakes are created by milling precursor particles characterized by a precursor composition that provides sufficient malleability to form a planar shape from a non-planar starting shape when milled, and wherein overall amounts of elements from Groups IB, IIIA and/or VIA contained in the precursor particles combined are at a desired stoichiometric ratio of the elements.
2 . The material of claim 1 wherein the milling transforms at least 50% of the precursor particles into microflakes.
3 . The material of claim 1 wherein the milling transforms at least 95% of the precursor particles into microflakes.
4 . The material of claim 1 wherein the milling transforms substantially all of the precursor particles into microflakes.
5 . The material of claim 1 wherein precursor particles are 10 microns or larger when measured along their longest dimension.
6 . The material of claim 1 wherein the milling occurs in an oxygen free atmosphere to create oxygen free microflakes.
7 . The material of claim 1 wherein the milling occurs in an inert gas environment to create oxygen free microflakes.
8 . The material of claim 1 wherein the milling occurs at room temperature.
9 . The material of claim 1 wherein the milling occurs at a cryogenic temperature.
10 . The material of claim 1 wherein the milling occurs at a milling temperature wherein all elements in the precursor particles are solids and have the precursor particles have a sufficient ductility at the milling temperature to form the planar shape from the non-planar starting shape.
11 . The material of claim 1 wherein the milling occurs at a temperature less than 15 degrees C.
12 . The material of claim 1 wherein the milling occurs at a temperature less than −200 degrees C.
13 . The material of claim 1 wherein the precursor particles are single metal particles.
14 . The material of claim 1 wherein the precursor particles are elemental particles.
15 . The material of claim 1 wherein the precursor particles are alloy particles.
16 . The material of claim 1 wherein the precursor particles are binary alloy particles.
17 . The material of claim 1 wherein the precursor particles are ternary alloy particles.
18 . The material of claim 1 wherein the precursor particles are quaternary alloy particles.
19 . The material of claim 1 wherein the precursor particles are solid solution particles.
20 . The material of claim 1 wherein the microflakes comprises only Group IIIA materials.
21 . The material of claim 1 wherein the microflakes comprises only Group IB and Group IIIA materials.
22 . The material of claim 1 wherein the microflakes comprises only Group IB and Group VIA materials.
23 . The material of claim 1 wherein the microflakes comprises only Group IIIA and Group VIA materials.
24 . The material of claim 1 wherein molar ratio of Group IB material to Group IIIA material in the plurality of microflakes is larger than 1.0.
25 . The material of claim 1 wherein the precursor particles are elemental particles and wherein milling forms alloy microflakes from the elemental particles.
26 . The material of claim 1 wherein the precursor particles are chalcogenide particles characterized by a stoichiometric ratio of elements that provides the precursor particles with sufficient ductility to form a planar shape from a non-planar starting shape.
27 . The material of claim 1 wherein the precursor particles are selected from one of the following: copper selenide, indium selenide, or gallium selenide.
28 . The material of claim 1 wherein stoichiometric ratio of elements varies between microflakes so long as the overall amount in all of the microflakes combined is at the desired stoichiometric ratio.
29 . The material of claim 1 further comprising size discriminating the microflakes to exclude microflakes above a desired length.
30 . The material of claim 1 further comprising size discriminating the microflakes to exclude microflakes above a desired thickness.
31 . The material of claim 1 further comprising size discriminating the microflakes to control size variation of microflakes to a deviation of less than about 30% of the mean length and about 30% in mean thickness.
32 . The material of claim 1 wherein one standard deviation from a mean length of the microflakes is less than 100 nm.
33 . The material of claim 1 wherein one standard deviation from a mean length of the microflakes is less than 50 nm.
34 . The material of claim 1 wherein one standard deviation from a mean thickness of the microflakes is less than 10 nm.
35 . The material of claim 1 wherein one standard deviation from a mean thickness of the microflakes is less than 5 nm.
36 . The material of claim 1 wherein substantially each of the microflakes has a thickness about 100 nm or less.
37 . The material of claim 1 further comprising coating the microflakes with at least one layer of material containing a group VIA element.
38 . The material of claim 1 further comprising coating the microflakes with at least one layer of material containing selenium and/or a selenide.
39 . The material of claim 1 wherein the microflakes form a dry powder.
40 . The material of claim 1 wherein the microflakes have an aspect ratio of at least about 10 or more.
41 . The material of claim 1 wherein the microflakes have an aspect ratio of at least about 15 or more.
42 . The material of 1 wherein the microflakes contain sodium.
43 . The material of claim 1 wherein the microflakes contains at least one of the following materials: Cu—Na, In—Na, Ga—Na, Cu—In—Na, Cu—Ga—Na, In—Ga—Na, Na—Se, Cu—Se—Na, In—Se—Na, Ga—Se—Na, Cu—In—Se—Na, Cu—Ga—Se—Na, In—Ga—Se—Na, Cu—In—Ga—Se—Na, Na—S, Cu—S—Na, In—S—Na, Ga—S—Na, Cu—In—S—Na, Cu—Ga—S—Na, In—Ga—S—Na, or Cu—In—Ga—S—Na.
44 . The material of claim 1 further comprising an ink containing a sodium compound with an organic counter-ion or a sodium compound with an inorganic counter-ion.
45 . A method of using the material of claim 1 comprising heating the microflakes in a non-oxygen chalcogen atmosphere to form a dense film.
46 . A method of using the material of claim 1 and further comprising heating the material on a substrate to form a film and then forming a layer of sodium-containing material on the film.