Inkjet Printing of Liquid Silicon.

A precursor solution for semiconducting Si called liquid Si (liq-Si) is synthesized, and semiconducting Si is inkjet-printed. Satisfactory inkjet discharge is achieved using liq-Si consisting of liquid-phase polysilane with an average molecular weight of 2500 g mol-1 . The printed liq-Si is converted into amorphous Si by heating at 400 °C. The resulting Si film has a flat surface with a root-mean-square roughness of 0.8 nm. These results are extended to n- and p-type Si films by synthesizing liq-Si chemically doped with P and B compounds, respectively. Liq-Si inkjet printing produces Si patterns without using traditional photolithography processes, opening up the field of printed Si electronics.