Direct integration of subwavelength structure on a GaAs solar cell by using colloidal lithography and dry etching process

Abstract

An antireflective subwavelength structure (SWS) was realized on the InGaP layer of a GaAs solar cell by using colloidal lithography followed by dry etching process. The fabricated SWS with an aspect ratio of 1.33 and a period of 300 nm showed enhanced optical properties and device characteristics. The average reflectance of the SWS surface of the GaAs solar cell was 7.1% in the wavelength range between 300 and 1000 nm. More solar energy was absorbed by the GaAs solar cell due to the lowered surface reflection by the SWS. It is the dominant factor in the 28.2% improvement of the power-conversion efficiency (η) of the SWS-integrated GaAs solar cell as compared to that of the GaAs solar cells without SWS.