Growth mechanism and dynamics of in-plane solid-liquid-solid silicon nanowires

In this paper, we investigate the growth mechanism and dynamic behavior of in-plane solid-liquid-solid (IPSLS) silicon nanowires (SiNWs), mediated by indium drops which transform hydrogenated amorphous silicon into crystalline SiNWs. Two distinctive growth modes of the SiNWs have been identified: (1) the grounded-growth (GG) mode in which the produced SiNWs are fixed to the substrate and (2) the suspended-growth (SG) mode where the SiNWs are carried by and move together with the catalyst drops. A comparative study of the SiNWs produced in SG and GG modes provides important insights into the IPSLS mechanism and reveals the unique growth balance condition in the moving SiNWs/catalyst drop system. For the GG-SiNWs, the interplay between the front absorption interface and the rear deposition interface of the catalyst drop leads to an interesting growth dynamics, which can be described by a kinetic equation model. For the SG-SiNWs, direct evidences of the rolling-forward behavior of the liquid catalyst drop have been witnessed.