Production of pristine, sulfur-coated and silicon-alloyed germanium nanoparticles via laser pyrolysis

Here we demonstrate production of three types of germanium containing nanoparticles (NPs) by laser pyrolysis of GeH₄ and characterize their sizes, structures and composition. Pristine Ge NPs were fabricated with 50 standard cubic centimeter per minute (sccm) of GeH₄ and 25 sccm of SF₆ as a photosensitizer gas, while sulfur-coated Ge NPs were produced with 25 sccm of GeH₄ and 50 sccm of SF₆. The laser pyrolysis of SiH₄/GeH₄ mixtures produced Si_1-xGe_x alloy NPs. Effects of key process parameters including laser intensity and gas flow rates on NP properties have been investigated. The ability of the laser pyrolysis technique to flexibly produce a variety of germanium-containing NPs, as illustrated in this study shows promise for commercial-scale production of new nanomaterials as high purity dry powders.