Effect of MACE parameters on length of porous silicon nanowires (PSiNWs)

Silicon nanowire-based devices have properties such as optical, electronic, and physical that can outperform their traditional counterparts in various ways because the silicon nanowires (SiNWs) have a high surface Si area to volume ratio and unique quasi-one-dimensional (1D) electronic structure. A variety of approaches are being classified into top-down and bottom-up methods to fabricate SiNWs. The present work demonstrates the synthesis of porous SiNWs (PSiNWs) through the metal-assisted chemical etching (MACE). The MACE produces PSiNWs using an aqueous solution composed of hydrofluoric acid (HF) and hydrogen peroxide (H2O2). Effect of MACE parameters such as H2O2 concentration, etching time, and Si wafer resistivity variation on the morphological characteristics (especially length) of PSiNWs are compared and thoroughly discussed. The structure and morphology of PSiNWs are characterized by transmission electron microscopy (TEM), environmental scanning electron microscopy (ESEM), and X-ray diffraction (XRD). The XRD data show the PSiNWs crystal growth direction.