TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - The group IB-chalcogenide particles are copper selenide (CuxSey), where x is 2-1 and y is 1-2. The group IIIA-chalcogenide particles are indium selenide (InxSey), where x is 1-6 and y is 0-7. The group IIIA-chalcogenide particles are GaxSey, where x is 1-2 and y is 1-3. The atmosphere is comprised of at least selenium. The precursor layer of the particles are solid solution of any of the preceding elements, copper, indium, gallium, selenium, copper indium, copper gallium, indium gallium, sodium, a sodium compound, sodium fluoride, sodium indium sulfide, copper selenide, copper sulfide, indium selenide, indium sulfide, gallium selenide, gallium sulfide, copper indium selenide, copper indium sulfide, copper gallium selenide, copper gallium sulfide, indium gallium selenide, indium gallium sulfide, copper indium gallium selenide, and/or copper indium gallium sulfide. The particles contains at least one of the materials selected from copper-sodium (Cu-Na), indium-sodium (In-Na), gallium-sodium (Ga-Na), copper-indium-sodium (Cu-In-Na), copper-gallium-sodium (Cu-Ga-Na), indium-gallium-sodium (In-Ga-Na), sodium selenide (Na-Se), copper-selenium-sodium (Cu-Se-Na), indium-selenium-sodium (In-Se-Na), gallium-selenium-sodium (Ga-Se-Na), copper-indium-selenium-sodium (Cu-In-Se-Na), copper-gallium-selenium-sodium (Cu-Ga-Se-Na), indium-gallium-selenium-sodium (In-Ga-Se-Na), copper-indium-gallium-selenium-sodium (Cu-In-Ga-Se-Na), sodium sulfate (Na-S), copper-sulfur-sodium (Cu-S-Na), indium-sulfur-sodium (In-S-Na), gallium-sulfur-sodium (Ga-S-Na), copper-indium-sulfur-sodium (Cu-In-S-Na), copper-gallium-sulfur-sodium (Cu-Ga-S-Na), indium-gallium-sulfur-sodium (In-Ga-S-Na), or copper-indium-gallium-sulfur-sodium (Cu-In-Ga-S-Na).    TECHNOLOGY FOCUS - METALLURGY - The precursor layer of the particles and a layer in contact with the precursor layer and contains at least one of the following materials group IB, IIIA, VIA, IA, a binary and/or their multinary alloy.