TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: In the process, the first element is Cu, the second element is Zn or Cd, the third element is Ge or Sn, and the chalcogen is S. The source of chalcogen is also the source of the first element, the source of the second element, or the source of the third element. The source of the first element is also the source of the second element or the source of the third element, or the source of the second element is the source of the third element. The process prepares a composition of the formula (E1)2(E2)1(E3)1(chalcogen)4.E1=the first element and is one or more of Cu, Ag, and Au;E2=the second element and is one or more of Zn, Cd, or Hg; andE3=the third element and is one or more of Ge, Sn, or Si.Also, the process prepares a composition of the formula Cu2ZnSnSe4, Cu2ZnGeS4, Cu2ZnSnS3Se1, Cu2CdSnS4, or Cu2ZnSnS4. The flux is removed from the reaction mixture after step (b) or step (c) by washing with a flux solvent. The flux solvent is water, alcohol, amide, tetrahydrofuran, ketone, ester, ether, dimethylsulfoxide, trimethylphosphate, triethylphosphate, dimethylcarbonate, aqueous ammonia, ammonium hydroxide, diethylcarbonate, methanol, ethanol, iso-propanol, dimethylformamide, acetone, ethylmethylketone, ethyl acetate, butyl acetate, ethyl ether, dibutyl ether, or a mixture. The flux is a salt that comprises: (a) one or more cations selected from cesium, rubidium, barium and lanthanum, and optionally comprises one or more cations selected from lithium, sodium, potassium, copper, silver, gold, beryllium, magnesium, calcium, strontium, zinc, cadmium, mercury, boron, aluminum, gallium, indium, thallium, scandium, and yttrium; and (b) one or more anions selected from fluoride, chloride, bromide, iodide, oxide, hydroxide, sulfide, selenide, telluride, carbonate, silicate, sulfate, phosphate, pyrophosphate, sulfate, sulfonic, and phosphonic anions. The flux comprises chloride, bromide, or iodide. The flux comprises barium chloride (BaCl2), cadmium chloride (CdCl2), cesium aluminum chloride (CsAlCl4), cesium bromide (CsBr), cesium chloride (CsCl), cesium fluoride (CsF), cesium iodide (CsI), potassium chloride (KCl), lanthanum chloride (LaCl3), lithium chloride (LiCl), magnesium chloride (MgCl2), sodium chloride (NaCl), rubidium bromide (RbBr), rubidium chloride (RbCl), rubidium iodide (RbI), zinc chloride (ZnCl2), or a mixture. The reaction mixture is heated in an open container. The reaction mixture is heated to a temperature of 400-800 degrees C. The process further comprises isolating a composition of the formula (E1)2(E2)1(E3)1(chalcogen)4; and isolating a composition of the formula Cu2ZnSnSe4, Cu2ZnGeS4, Cu2ZnSnS3Se, Cu2CdSnS4, or Cu2ZnSnS4. EXAMPLE - No suitable example given.