Low Temperature Colloidal Synthesis of Silicon Nanorods from Isotetrasilane, Neopentasilane, and Cyclohexasilane

Isotetrasilane, neopentasilane, and cyclohexasilane were studied as reactants for silicon (Si) nanorod growth in solution. These polysilane hydrides were found to enable lower growth temperatures in solution than any other silane reactants used to date. Cyclohexasilane enabled the lowest growth temperature of 200 °C, using a single-step solution–liquid–solid (SLS) reaction from tin (Sn) seeds. The potential for nanorod growth is determined by the reactivity of the silane. Cyclohexasilane is the most reactive of the polysilane hydrides studied here, requiring the lowest energy for dehydrogenation. The formation of silylene by cycolhexasilane also facilitates chemisorption onto the Sn surface during nanorod growth. Relatively bright photoluminescence (emission quantum yields of 2%) could still be achieved from Si nanorods grown at these low temperatures.