Pencil-shaped silicon nanowire synthesis and photovoltaic application

Pencil-shaped silicon nanowires (SiNWs) were synthesized by colloidal lithography and inductively coupled plasma reactive ion etching for photovoltaic application. Light reflectance of below 10% could be obtained by the asymmetric pencil-shaped SiNW array. The pencil-shaped SiNW structure and properties were investigated and compared with metal catalyzed electroless etching (MCEE) and nanoimprinted SiNWs. Single-junction solar cells consisting of pencil-shaped n-SiNW substrates and p-Si shell layer grown by chemical vapor deposition were fabricated. A combination of two-step H2 annealing and back surface field formation was applied to improve the solar cell properties. Good crystal quality and surface of pencil-shaped SiNWs provided an excellent solar cell junction interface. The great light trapping of the pencil-shaped SiNW solar cell could enhance the conversion efficiency by more than 0.6% compared to the solar cells using MCEE and nanoimprinted SiNWs.