A representative printable composition comprises a liquid or gel suspension of a plurality of metallic particles; a plurality of semiconductor particles; and a first solvent. The pluralities of particles may also be comprised of an alloy of a metal and a semiconductor. The composition may further comprise a second solvent different from the first solvent. In a representative embodiment, the first solvent comprises a polyol or mixtures thereof, such as glycerin, and the second solvent comprises a carboxylic or dicarboxylic acid or mixtures thereof, such as glutaric acid. In various embodiments, the metallic particles and the semiconductor particles are nanoparticles between about 5 nm to about 1.5 microns in any dimension. A representative metallic and semiconductor particle ink can be printed and annealed to produce a conductor.