Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Lithography-Free Fabrication of Large Area Subwavelength Antireflection Structures Using | Nanoscale Res Lett 2009 4 364-370 DOI S11671-009-9255-4 NANO EXPRESS Lithography-Free Fabrication of Large Area Subwavelength Antireflection Structures Using Thermally Dewetted Pt Pd Alloy Etch Mask Youngjae Lee Kisik Koh Hyungjoo Na Kwanoh Kim Jeong-Jin Kang Jongbaeg Kim Received 26 November 2008 Accepted 8 January 2009 Published online 24 January 2009 to the authors 2009 Abstract We have demonstrated lithography-free simple and large area fabrication method for subwavelength antireflection structures SAS to achieve low reflectance of silicon Si surface. Thin film of Pt Pd alloy on a Si substrate is melted and agglomerated into hemispheric nanodots by thermal dewetting process and the array of the nanodots is used as etch mask for reactive ion etching RIE to form SAS on the Si surface. Two critical parameters the temperature of thermal dewetting processes and the duration of RIE have been experimentally studied to achieve very low reflectance from SAS. All the SAS have well-tapered shapes that the refractive index may be changed continuously and monotonously in the direction of incident light. In the wavelength range from 350 to 1800 nm the measured reflectance of the fabricated SAS averages out to 5 . Especially in the wavelength range from 550 to 650 nm which falls within visible light the measured reflectance is under . Keywords Subwavelength antireflection structure Nanostructure Thermal dewetting Self-agglomeration Introduction Solar energy is considered as one of the most important alternative energy sources and solar cell has been actively Y. Lee K. Koh H. Na K. Kim J. Kim El School of Mechanical Engineering Yonsei University 134 Shinchon-dong Seodaemun-Gu Seoul 120-749 Korea e-mail kimjb@ jongbaeg@ . Kang Korea Institute of Industrial Technology KITECH Bucheon-si Kyunggi-do Korea studied as promising solar energy conversion device. For its practical use however there are numbers of technical barriers to be overcome .
