Formation of a Porous Silicon Layer by Electrochemical Etching and Application to the Silicon Solar Cell

Abstract

SiN x thin film grown by plasma-enhanced chemical vapor deposition PECVD has conventionally been used as an antireflection layer of the silicon solar cell. In this work, a porous silicon PS layer formed by electrochemical etching was shaped on the surface of a crystalline silicon wafer for a simple alternative of anti-reflection coating ARC . The etching solution was prepared by mixing HF and ethanol for efficient bubble elimination on the silicon surface during the etching process. The anodization of the silicon surface was performed under a constant current, and the process parameters, such as current density and etching time including volume fraction of HF to ethanol in the solution, were carefully tuned to minimize the surface reflectance of the CZ silicon wafer with sheet resistance of 35-40 Q. The PS layer as an anti-reflection coating in the solar cell was compared with conventional PECVD SiN x thin film by measuring the surface reflectance of the cell. Also, Photovoltaic I-V properties and the quantum efficiencies of the cells with PS layers were measured.

Electrical and Photoelectrical Properties of Reduced Graphene Oxide—Porous Silicon Nanostructures

“…Changing the band energy structure of silicon when moving from bulk to nanocrystals due to quantum confinement allows to significantly widen the absorption spectra of photonic devices based on the PS. Using multilayered photosensitive structures based on silicon nanomaterials allows to achieve a notable improvement in sunlight to energy conversion efficiency and to design the new generation photodetectors [ 25 – 27 ]. Also, PS is a perfect candidate for deposition and infiltration of graphene nanosheets and GO into sponge-like geometrical structure of the substrate [ 28 , 29 ].…”