Photovoltaic electrical properties of aqueous grown ZnO antireflective nanostructure on Cu(In,Ga)Se-2 thin film solar cells

Abstract

A solution-grown subwavelength antireflection coating has been investigated for enhancing the photovoltaic efficiency of thin film solar cells. The 100-nm-height ZnO nanorods coating benefited the photocurrent of Cu(In, Ga) Se-2 solar cells from 31.7 to 34.5 mA/cm(2) via the decrease of surface light reflectance from 14.5% to 7.0%, contributed by the gradual refractive index profile between air and AZO window layer. The further reduction of surface reflectance to 2.3% in the case of 540-nm-height nanorods, yet, lowered the photocurrent to 29.5 mA/cm(2), attributed to the decrease in transmittance. The absorption effect of hydrothermal grown ZnO nanorods was explored to optimize the antireflection function in enhancing photovoltaic performances. (C) 2013 Optical Society of America