Open AccessGaAs nanopillar arrays with suppressed broadband reflectance and high optical quality for photovoltaic applications
Author(s) -
Reza Sanatinia,
Kashif M. Awan,
Shagufta Naureen,
Nicklas Anttu,
Evert Ebraert,
Srinivasan Anand
Publication year - 2012
Publication title -
optical materials express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 66
ISSN - 2159-3930
DOI - 10.1364/ome.2.001671
Subject(s) - nanopillar , materials science , broadband , optoelectronics , photovoltaic system , reflectivity , optics , quality (philosophy) , nanotechnology , nanostructure , ecology , physics , biology , philosophy , epistemology
We report on fabrication and optical characterization of GaAs nanopillar (NP) arrays, obtained using a combination of low-cost mask generation by self-assembled silica particles (nanosphere lithography) and dry etching. Tapered structures (conical and frustum NP arrays) are fabricated by appropriate optimization of process parameters. Significant suppression of surface reflectance is observed for both geometries over a broad wavelength range. Simulations, based on finite difference time domain (FDTD) method, show good agreement with reflectivity measurements and serve as a guideline for design of NPs and understanding their interaction with light. A combination of wet chemical etching and sulfur-based passivation of GaAs NPs, results in more than one order of magnitude enhancement in PL intensity and recovery of PL line-width, which is very promising for photovoltaic applications. (C) 2012 Optical Society of Americ