Showing papers by "Biswajit Das published in 2004"
TL;DR: In this paper, the results of a systematic study of thin-film alumina templates on silicon and other substrates were presented, and the dependence of pore morphology and pore formation rate on process parameters was evaluated.
Abstract: This paper presents the results of a systematic study of the fabrication of thin-film alumina templates on silicon and other substrates. Such templates are of significant interest for the low-cost implementation of semiconductor and metal nanostructure arrays. In addition, thin-film alumina templates on silicon have the potential for nanostructure integration with silicon electronics. Formation of thin-film alumina templates on silicon substrates was investigated under different fabrication conditions, and the dependence of pore morphology and pore formation rate on process parameters was evaluated. In addition, process conditions for improved pore size distribution and periodicity were determined. The template/silicon interface, important for nanostructure integration on silicon, was investigated using capacitance-voltage measurements and electron microscopy, and was found to be of good device quality. Formation of thin-film alumina templates on nonsilicon substrates such as glass, indium-tin-oxide-coated glass, and silicon carbide was also investigated.
16 citations
TL;DR: In this article, the experimental observation of room temperature capacitance-voltage oscillations in porous silicon (PS) is presented, which suggests density-of-states discontinuities in the PS nanostructures to be the likely origins of the oscillations.
Abstract: This paper presents the experimental observation of room temperature capacitance–voltage oscillations in porous silicon (PS). Analysis of the experimental data suggests density-of-states discontinuities in the PS nanostructures to be the likely origins of the oscillations. From the experimental data, a sub-band energy separation of 0.19 eV is estimated for the dominant silicon nanostructures. This corresponds to a nanostructure dimension of approximately 3 nm , which agrees well with the value expected for the PS fabrication conditions.
4 citations
01 Jan 2004
TL;DR: In this article, a novel nanostructure based coating technology was developed to improve corrosion resistance for steel in LBE at elevated temperatures (500 600C), as well as provide long-term reliability under thermal cycling.
Abstract: The objective of this project is to develop a novel nanostructure based coating technology that will provide significantly improved corrosion resistance for steel in LBE at elevated temperatures (500 600C), as well as provide long-term reliability under thermal cycling. The nanostructure based coatings will consist of a layer of nanoporous alumina with the pores filled with an oxidizing metal such as Cr, followed by a capping layer of alumina. Alumina, which is a robust anti-corrosion material, provides corrosion resistance at elevated temperatures. The Cr serves two purposes: (1) it acts as a solid filler material for the pores in the alumina, enhancing its mechanical and chemical integrity, and (2) it acts as a second layer of defense against corrosion by providing a replenishable source of Cr (for the formation of a Chromium oxide protective layer) in case the alumina layer is compromised. The innovation of this project is the use of a nanoporous alumina layer for the coating, which is mechanically flexible and can expand and contract with the underneath steel surface. As a result, the mechanical integrity of the coating is preserved under thermal cycling. In addition to their usefulness at higher temperatures, the proposed coatings can also provide increased reliability at lower temperatures by complementing the oxygen control technique. The nanostructure based coatings developed in this project will significantly enhance the long-term reliability of steel structures in LBE at elevated temperatures and under thermal cycling. Work Proposed for Funding Year 2004-2005, Goals, and Expected Results: Year 1 of the project will develop the coating technology and evaluate the structural integrity of the coatings at elevated temperatures and under thermal cycling. The project goals and expected results for Year 1 are to (i) develop the technology to create thick nanoporous alumina layers on HT-9 and EP-823 steel, (ii) deposit Cr nanowires inside the alumina pores, (iii) create capping layers of alumina on the Cr nanowires, and (iv) evaluation of the structural integrity of the coatings at elevated temperatures and under thermal recycling. Funding Requested: Funding Year: 2004-2005 2005-2006 2006-2007 Total (K$) 128 111 112