Novel synthesis of 1-D silicon nanowires grown on pyramidal black silicon substrates and intense visible emission

Abstract

This work shows a new way to grow 1-D Silicon Nanowires (SiNWs) over pyramidal black silicon used as substrates. These nanostructures are grown by the plasma-assisted vapor–liquid-solid (VLS) as a bottom-up process, using tin thin films as a catalytic metal and dichlorosilane gas as a silicon precursor. SiNWs were obtained with diameters from 300-600 nm and 4–6 µm lengths on the black silicon surface. Due to the pyramid-shaped and porous nature of the black silicon surface, SiNWs form a complex mesh nanostructure. This network has a large surface area and exhibits intense and effective photoluminescence with a peak in the green spectrum, which is attributed to the quantum confinement effect that occurred in small nc-Si embedded inside SiNWs. These structural configurations hold significant promise for applications in optical biosensors, solar cells, and other prospective fields.