The Silicon Solar Cell with Selective Nanoscrew Pillars Fabricated by Cesium Chloride Self-Assembly Lithography and Dry Etching

A kind of nanoscrew pillars is selectively made on the surface of silicon solar cell to improve the solar cell performance. Nanoscrew pillars with rough side wall are fabricated by Cesium Chloride (CsCl) self-assembly lithography and inductively coupled plasma (ICP) dry etching. The nanoscrew pillars have the average diameter of from 200 nm to 1.5 mu m with the screw cycle of 150 nm linearly determined by the etching cycles. Compared with the nanopillars of smooth side wall, the nanoscrew pillars have the better antireflection property for the short wavelength ranging from 300 to 550 nm and better hydrophobicity property with the static similar to 137 degrees contact angle due to the special morphology. For the silicon solar cell covered by nanoscrew pillars on all over the entire front surface, the photovoltaic conversion efficiency (PCE) is not desirable with only 13.34%. For the solar cell covered by nanoscrew pillars only on the active area and metal electrode pattern on plain area, the PCE has been improved to 15.39% with a short circuit current density (J(sc)) of 38.21 mA/cm(2) and an open circuit voltage (V-oc) of 558.0 mV mainly benefiting from the better contacts of metal electrode pattern.