Patent ID: 8513052

Claim:
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.