Group 3a ink and methods of making and using same

1. A Group 3a ink, comprising, as initial components:

a polyamine solvent;

a Group 3a material/organic complex, wherein the Group 3a material/organic complex is a Group 3a material/carboxylate complex comprising an indium cation complexed with at least one carboxylate anion selected from 2-ethylhexanoate, 2-ethylbutyrate, acetylacetonoate, trimethylacetate, acetate, formate and isovalerate; and,

a reducing agent selected from ammonium formate, formic acid, ammonium oxalate, heptaldehyde and oxalic acid;

wherein the molar ratio to the Group 3a material/organic complex is at least 10:1;

wherein the Group 3a ink is a stable dispersion and wherein the Group 3a ink is hydrazine and hydrazinium free.

2. The Group 3a ink of claim 1 , wherein the polyamine solvent is selected from ethylenediamine; diethylenetriamine; triethylenetetramine; tetramethylguanidine; 1,3-diaminopropane; 1,2-diaminopropane; and 1,2-diaminocyclohexane.

3. The Group 3a ink of claim 1 , wherein the Group 3a material/organic complex is a Group 3a material/carboxylate complex comprising an indium cation complexed with at least one carboxylate anion selected from 2-ethylhexanoate and 2-ethylbutyrate.

4. A method of preparing a Group 3a ink, comprising:

providing a Group 3a material/organic complex;

providing a reducing agent selected from ammonium formate, formic acid, ammonium oxalate, heptaldehyde and oxalic acid;

providing a polyamine solvent;

combining the Group 3a material/organic complex, the reducing agent and the polyamine solvent to produce the Group 3a ink;

wherein at least 10 molar equivalents of the reducing agent is provided relative to the Group 3a material/organic complex; wherein the Group 3a ink is a stable dispersion; and wherein the Group 3a ink is hydrazine and hydrazinium free.

5. A Group 3a ink prepared according to the method of claim 4 .

6. A method for providing a Group 3a metal on a substrate, comprising:

providing a substrate;

providing a Group 3a ink according to claim 1 ;

applying the Group 3a ink to the substrate forming a Group 3a precursor on the substrate;

treating the Group 3a precursor to provide a Group 3a metal on the substrate;

wherein >85 mol % of the Group 3a metal provided on the substrate is in a zero valence state.

7. The method of claim 6 , further comprising:

optionally, providing a Group 1a source comprising sodium;

providing a Group 1b source;

optionally, providing a supplemental Group 3a source;

optionally, providing a Group 6a sulfur source;

optionally, providing a Group 6a selenium source;

providing at least one Group 1a-1b-3a-6a precursor material comprising the Group 3a precursor material applied to the substrate, by optionally using the Group 1a source to apply a sodium material to the substrate, using the Group 1b source to apply a Group 1b material to the substrate, optionally using the supplemental Group 3a source to apply additional Group 3a material to the substrate, optionally using the Group 6a sulfur source to apply a sulfur material to the substrate and using the Group 6a selenium source to apply a selenium material to the substrate to form the Group 1a-1b-3a-6a precursor material;

treating the precursor material to form a Group 1a-1b-3a-6a material having a formula Na L X m Y n In (1−n) S p Se q ;

wherein X is at least one Group 1b material selected from copper and silver; wherein Y is the Group 3a material; wherein the Group 3a material is selected from gallium, indium and aluminum; wherein 0<L<0.75; wherein 0.25<m<1.5; wherein 0<n<1; wherein 0<p<2.5; wherein 0<q<2.5; and, wherein 1.8<(p+q)<2.5.

8. The method of claim 7 , wherein the Group 1a-1b-3a-6a material is a CIGS material having a formula Cu v In w Ga x Se y S z ; wherein 0.5<v<1.5; 0<w<1; 0≦x≦1; 0<y≦2.5; 0≦z<2.5; and w+x=1.