Ultra-broadband performance enhancement of thin-film amorphous silicon solar cells with conformal zig-zag configuration

An ultrathin amorphous silicon solar cell with conformal zig-zag nanoconfiguration is studied from both light-trapping and light-conversion perspectives. The design improves the front antireflection property, optimizes the rear metallic reflector, and elongates the optical path inside the photoactive layer. Compared to conventional nanoconfigurations, this system shows significant absorption enhancement in the whole amorphous silicon band and exhibits extremely low sensitivity to light polarization. The nano-optimization indicates that the short-circuit current density (light-conversion efficiency) of the 200-nm-thick solar cell can be 16.88 mA/cm(2) (13.38%), showing an enhancement factor of 32.90% (33.53%) from the planar system. (C) 2013 Optical Society of America