Tunable Conductivity of Germanium Thin Films Fabricated via Doped Colloidal Nanoparticle Sintering

This work describes a versatile, simple, and solution based approach for the synthesis of monodispersed, highly crystalline germanium nanoparticles (Ge NPs). With slight modification, this synthetic method can be used to produce Ge NPs doped with small amounts of transition metals. Through the incorporation of various dopants at different concentrations, it was possible to tune both the optical and electronic properties. Thin films fabricated from the various NPs displayed conductivities ranging from a few to a couple hundred nS/m. However, after thermally annealing the thin films, further enhancement to the S/m range was observed.