Nanosized Structural Anti-Reflection Layer for Thin Film Solar Cells

Abstract

A nanosized pattern layer was formed on the front surface (glass side) of the thin film solar cell using nanoimprint lithography with a Ni based moth-eye imprint mold in order to increase the total conversion efficiency of the amorphous silicon based thin film solar cell. The imprinted pattern layer had nanosized protrusions, which suppressed the reflection of light on the glass surfaces. The nanopatterns were formed using a methacryloxypropyl terminated poly(dimethylsiloxane) (MPDMS) based hard polymeric resin. The reflectance of the thin film solar cell significantly decreased because of the nanosized structural anti-reflection layer, and the total conversion efficiency of the cell increased about 3% compared to the identical solar cell without the nanosized pattern layer. Moreover, the surface exhibited a hydrophobic nature because of the surface nanopatterns and the self-assembled monolayer coating, and this hydrophobicity provided the solar cell with a self-cleaning functionality. (C) 2011 The Japan Society of Applied Physics