Dichalcogenide selenium ink and methods of making and using same

1. A method for preparing a Group 1a-1b-3a-6a material, comprising:

providing a substrate;

optionally, providing a Group 1a source comprising sodium;

providing a Group 1b source;

providing a Group 3a source;

optionally, providing a Group 6a sulfur source;

providing a Group 6a selenium source, wherein the Group 6a selenium source includes a selenium ink, comprising:

a chemical compound having a formula RZ—Se x —Z′R′; wherein Z and Z′ are each independently selected from the group consisting of sulfur, selenium and tellurium; wherein x is 2 to 20; wherein R is selected from the group consisting of H, C 1-20 alkyl group, a C 6-20 aryl group, a C 1-20 alkylhydroxy group, an arylether group and an alkylether group; wherein R′ is selected from the group consisting of a C 1-20 alkyl group, a C 6-20 aryl group, a C 1-20 alkylhydroxy group, an arylether group and an alkylether group; and

a liquid carrier, wherein the liquid carrier is a nitrogen containing solvent;

wherein the selenium ink comprises>1 wt % selenium; wherein the selenium ink is stable and wherein the selenium ink is hydrazine and hydrazinium free;

forming at least one Group 1a-1b-3a-6a precursor material on the substrate by optionally using the Group 1a source to apply sodium to the substrate, using the Group 1b source to apply a Group 1b material to the substrate, using the Group 3a source to apply a 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;

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

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

2. The method of claim 1 , wherein Z and Z′ are both sulfur.

3. The method of claim 1 , wherein Z and Z′ are both Selenium; and wherein R and R′ are each independently selected from the group consisting of a phenyl group, a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group and a tert-butyl group.

4. The method a claim 1 , wherein Z and Z′ are both sulfur; and wherein R and R′ are each independently selected from the group consisting of a phenyl group, a methyl group, an ethyl group, as propyl group, a butyl group, an isopropyl group and a tert-butyl group.

5. The method of claim 1 , wherein the liquid carrier is a liquid amine having a formula NR 3 , wherein each R is independently selected from the group consisting of a H, a C 1-10 alkyl group, a C 6-10 aryl group and a C 1-10 alkylamino group.

6. The method of claim 1 , wherein the liquid carrier is selected from the group consisting of ethylene diamine, diethylenetriamine, triethylenetetramine, n-butylamine, n-hexylamine, octylamine, 2-ethyl-1-hexylamine, 3-amino-1-propanol, pyridine, pyrrolidine and tetramethylguanidine.