TECHNOLOGY FOCUS - IMAGING AND COMMUNICATION - Preferred Method The substrate is coated with a transparent conductive coating. The applying step is carried out by a method selected from spin coating, dip coating, doctor blading, curtain coating, slide coating, spraying, slit casting, meniscus coating, screen printing, ink jet printing, pad printing, flexographic printing, and gravure printing. The annealing step is carried out at 200-800 degrees C. The anneal is carried out in an atmosphere comprising: at least one of: N2, Ar, He and/or forming gas; or is carried out in an atmosphere which further comprises vapors of at least one of: sulfur, selenium, and its compound.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The aqueous solvent or aqueous dispersion comprises water (1-99 wt.%), and further comprises ammonium hydroxide (0.1-35 wt.%), at least one additive each containing a metal (0.01-5 wt.%), selected from Li, Na, K, Mg, Ca, Sr, Ba, Sb and/or Bi. The source of Cu is at least one of Cu2S and Cu2Se. The source of Sn is at least one of SnSe, SnS, SnSe2, and SnS2. The source of Zn is at least one of metallic zinc, ZnS, and ZnSe. The solid component comprises particles having a particle size of 2-2000 nm. The dissolved component contains at least one of S, Se, Cu and Sn. The source of S is selected from elemental sulfur, CuS, Cu2S, SnS, SnS2 and/or ZnS. The source of Se is selected from elemental selenium, SnSe2, and SnSe. The substrate is selected from metal foil, glass, ceramic, aluminum foil coated with a layer of molybdenum, and/or polymer (preferably glass, plastic, polymer, ceramic, and aluminum foil). The substrate is coated with a molybdenum layer. The n-type semiconducting layer has at least one of: ZnS, CdS, InS, and their oxides, and selenides. The transparent conductive material is selected from doped ZnO, Indium-tin oxide, doped tin oxide, and carbon nanotubes.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The aqueous solvent or aqueous dispersion further comprises water soluble organic solvent. Preferred Definitions:    x,y=0-0.5;    z=0-1;    q=-0.5 to 0.5.    EXAMPLE - Aqueous ammonia dispersion by diluting pure hydrazine dispersion was prepared as follows: The deposition solution was prepared in two parts in glass vials under magnetic stirring: (A1) by dissolving Cu2S (0.573 g) and sulfur (0.232 g) in hydrazine (3 ml) and (B1) by mixing SnSe (0.790 g), Se (1.736 g) and Zn (0.32 g) with hydrazine (7 ml). After 3 days under magnetic stirring, solution (A1) had an orange transparent aspect, while (B1) was dark green and opaque. Solutions (A1) and dispersion (B1) were mixed (C1) under magnetic stirring for 4 hours. Dispersion (C1) (2 ml) were mixed with 25% aqueous ammonia (ammonium hydroxide) (2 ml) to form dispersion (D1). Films of dispersion (D1) were deposited on soda lime glass substrates coated with 700-1000 nm of molybdenum by spin coating at 800 revolution per minutes (rpm) and heated preferably in a tubular oven or on a covered hot plate at 425 degrees C for 1 minute. The coating and heating cycle was repeated 5 or 6 times before a final anneal at 540 degrees C was carried out for 10 minutes in the presence of sulfur vapor. Solar cells were fabricated from the above-described Cu2ZnSn(Se,S)4 films by deposition of CdS buffer layer (60 nm) by chemical bath deposition, insulating ZnO (100 nm) and ITO (indium-doped zinc oxide) (130 nm) by sputtering. In addition to the shown structure, Ni/Al metal contacted and MgF coatings (110 nm) were deposited by electron-beam evaporation. Total area photovoltaic device efficiency under simulated 1.5 AM illumination was 7.06%, with open circuit voltage (Voc) of 530 mV, short circuit current density (Jsc) of 25 mA/cm2 and fill factor (FF) of 53%. On average, the efficiencies of 6-layer devices were only 1 absolute % lower than 5-layer reference devices spin coated from twice as concentrated pure hydrazine solution (C1). Further optimization was expected to lead to similar device performance values between the two routes.