ABSTRACT
In the past few years, there has been an enormous and growing interest in the development of nanostructure materials to improve the light harvesting efficiency for achieving high-efficiency Si solar cells while maintaining low cost. Feasible silicon nanostructures [1–4] such as silicon nanowires (SiNWs) and silicon nanoholes (SiNHs) have gained much attention due to their unique properties and possible applications in the fields of nanoelectronics [5–8], nanooptoelectronics [8,9], nanophotovolatics [9–11], and for sensor applications [12]. Various methods have been developed to prepare one-dimensional (1D) silicon nanostructures. They include laser ablation [13], physical vapor deposition [14], and chemical vapor deposition [15,16] which is a bottom-up approach [17]. However, most methods often result in randomly oriented SiNWs and their diameters and lengths have a wide distribution, which limit the applications to real optoelectronic devices. Nanoelectronics and nanooptoelectronics generally require vertically aligned, tunable length, and high-density nanowires to obtain processing compatibility.
