Papers by Marya Lieberman
The Journal of Physical Chemistry B, 2003
This is the report of a DOE-sponsored workshop organized to discuss the status of our understandi... more This is the report of a DOE-sponsored workshop organized to discuss the status of our understanding of charge-transfer processes on the nanoscale and to identify research and other needs for progress in nanoscience and nanotechnology. The current status of basic electron-transfer research, both theoretical and experimental, is addressed, with emphasis on the distance-dependent measurements, and we have attempted to integrate terminology and notation of solution electron-transfer kinetics with that of conductance analysis. The interface between molecules or nanoparticles and bulk metals is examined, and new research tools that advance description and understanding of the interface are presented. The present state-of-the-art in molecular electronics efforts is summarized along with future research needs. Finally, novel strategies that exploit nanoscale architectures are presented for enhancing the efficiences of energy conversion based on photochemistry, catalysis, and electrocatalysis principles.
Journal of Physical Chemistry B, 2003
This is the report of a DOE-sponsored workshop organized to discuss the status of our understandi... more This is the report of a DOE-sponsored workshop organized to discuss the status of our understanding of charge-transfer processes on the nanoscale and to identify research and other needs for progress in nanoscience and nanotechnology. The current status of basic electron-transfer research, both theoretical and experimental, is addressed, with emphasis on the distance-dependent measurements, and we have attempted to integrate terminology and notation of solution electron-transfer kinetics with that of conductance analysis. The interface between molecules or nanoparticles and bulk metals is examined, and new research tools that advance description and understanding of the interface are presented. The present state-of-the-art in molecular electronics efforts is summarized along with future research needs. Finally, novel strategies that exploit nanoscale architectures are presented for enhancing the efficiences of energy conversion based on photochemistry, catalysis, and electrocatalysis principles.
Macromolecules, 2007
... 12) Kielhorn, L.; Muthukumar, M. J. Chem. Phys. 1999, 111, 2259. ...
Langmuir, 2006
We demonstrate a guided self-assembly approach to the fabrication of DNA nanostructures on silico... more We demonstrate a guided self-assembly approach to the fabrication of DNA nanostructures on silicon substrates. DNA oligonucleotides self-assemble into "rafts" 8 × 37 × 2 nm in size. The rafts bind to cationic SAMs on silicon wafers. Electron-beam lithography of a thin poly(methyl methacrylate) (PMMA) resist layer was used to define trenches, and (3-aminopropyl)triethoxysilane (APTES), a cationic SAM precursor, was deposited from aqueous solution onto the exposed silicon dioxide at the trench bottoms. The remaining PMMA can be cleanly stripped off with dichloromethane, leaving APTES layers 0.7-1.2 nm in thickness and 110 nm in width. DNA rafts bind selectively to the resulting APTES stripes. The coverage of DNA rafts on adjacent areas of silicon dioxide is 20 times lower than on the APTES stripes. The topographic features of the rafts, measured by AFM, are identical to those of rafts deposited on wide-area SAMs. Binding to the APTES stripes appears to be very strong as indicated by "jamming" of the rafts at a saturation coverage of 42% and the stability to repeated AFM scanning in air.
Langmuir, 2002
Two resorcinarene surfactants with sulfur-functionalized headgroups have been evaluated for their... more Two resorcinarene surfactants with sulfur-functionalized headgroups have been evaluated for their ability to stabilize dispersions of midnanometer (16-87 nm)-sized gold particles in organic solvents. Citratestabilized colloidal gold nanoparticles were extracted from aqueous solutions into toluene or chloroform by tetrabenzylthiol resorcinarene 1 or tetraarylthiol resorcinarene 2. The nanoparticle dispersions were subjected to various conditions and monitored for changes in plasmon absorption intensity. The stability of the dispersions was dependent on the chemisorptive properties of the surfactant headgroup, with tetrabenzylthiol 1 being the more effective dispersant. Nanoparticles encapsulated by 1 were also highly robust, demonstrated good resistance to alkanethiol-induced flocculation, and could be redispersed after repeated precipitations in polar solvents. Surface-enhanced Raman scattering analysis and X-ray photoelectron spectroscopic studies confirmed significant differences in the chemisorptive properties of tetrathiols 1 and 2, indicating that surface passivation is an important factor in the dispersibility of colloidal gold nanoparticles in nonpolar solvents.
Annals of The New York Academy of Sciences, 2002
Abstract: Quantum-dot cellular automata (QCA) is a scheme for molecular electronics in which info... more Abstract: Quantum-dot cellular automata (QCA) is a scheme for molecular electronics in which information is transmitted and processed through electrostatic interactions between charges in an array of quantum dots. QCA wires, majority gates, clocked cell operation, and (recently) true power gain between QCA cells has been demonstrated in a metal-dot prototype system at cryogenic temperatures. Molecular QCA offers very high device densities, low power dissipation, and ways to directly integrate sensors with QCA logic and memory elements. A group of faculty at Notre Dame has been working to implement QCA at the size scale of molecules, where room-temperature operation is theoretically predicted. This paper reviews QCA theory and the experimental measurements in metal-dot QCA systems, and describes progress toward making QCA molecules and working out surface attachment chemistry compatible with QCA operation.
Hierarchical self-assembly was used to construct mesoscale DNA objects as eventual templates for ... more Hierarchical self-assembly was used to construct mesoscale DNA objects as eventual templates for molecular electronic circuitry. DNA tiles were assembled from single-stranded precursors. The tiles measure 4 nm x 12 nm x 2 nm. They can be programmed to self-assemble into larger objects, such as a 4-tile raft 37 nm long. The composition and structure of the DNA rafts were characterized in solution by biochemical assays. Rafts were imaged on mica substrates under isopropanol by non-contact mode AFM, or alternately, were deposited on silicon wafers and imaged by non-contact mode AFM in air.
Langmuir, 2003
This paper describes self-assembled monolayers (SAMs) that contain embedded disulfide bonds and t... more This paper describes self-assembled monolayers (SAMs) that contain embedded disulfide bonds and the selective cleavage of the disulfides by electron-beam lithography (EBL). Phenyl(3-trimethoxysilylpropyl)disulfide (I) forms siloxane SAMs with a root-mean-square roughness of 1.8 Å. The disulfide bonds in I remain intact in the SAM and can react with dithiothreitol after monolayer formation, forming surface thiols, which can be derivatized with maleimide dyes. Atomic force microscopy (AFM) anodization and EBL have been used to create high-resolution patterns on the disulfide-containing monolayer. AFM anodization on monolayer I achieves 20-nm resolution lines with both topographic and chemical alterations in the patterned region. EBL with an accelerating voltage of 30 kV generates trenches 3-4 Å deep and 30 nm wide. According to AFM topographic and friction images, X-ray photoelectron spectroscopy damage simulation, and chemical rebinding tests, the chemical changes induced by EBL are consistent with cleavage of the disulfide bonds to form sulfhydryl groups. The resulting chemical patterns can be further developed by reaction with N-(1-pyrene)maleimide. (11) Golzhauser, A.; Eck, W.; Geyer, W.; Stadler, V.; Weimann, T.; Hinze, P.; Grunze, M. Adv. Mater. 2001, 13, 806-809. (12) (a) Maoz, R.; Frydman, E.; Cohen, S. R.; Sagiv, J. Adv. Mater. 2000, 12, 424-429. (b) Maoz, R.; Frydman, E.; Cohen, S. R.; Sagiv, J.
For quantum-dot cellular automata molecular electronic devices, one of the fundamental tasks is t... more For quantum-dot cellular automata molecular electronic devices, one of the fundamental tasks is to arrange the molecules on a surface in a controlled manner. In this report, we discuss a molecular lift off technique to form nanopatterns toward the development of molecular circuits. In our molecular lift off technique, we use electron beam lithography to form nano-trenches on a polymethylmethacrylate (PMMA) film on a SiO2 wafer. This wafer is soaked in a Creutz-Taube ion [(NH3)5Ru(pyrazine)Ru(NH3)5](o-toluenesulfonate)5 (CT5) aqueous solution. After residual PMMA removal, atomic force microscopy is used to investigate the resulting surface. Thirty-five nanometer CT5 lines are demonstrated on a SiO2 surface. Compared with other molecular nanopatterning techniques, ours is both economical and capable of high-resolution.
Quantum-dot cellular automata (QCA) is a scheme for molecular electronics in which information is... more Quantum-dot cellular automata (QCA) is a scheme for molecular electronics in which information is transmitted and processed through electrostatic interactions between charges in an array of quantum dots. QCA wires, majority gates, clocked cell operation, and (recently) true power gain between QCA cells has been demonstrated in a metal-dot prototype system at cryogenic temperatures. Molecular QCA offers very high device densities, low power dissipation, and ways to directly integrate sensors with QCA logic and memory elements. A group of faculty at Notre Dame has been working to implement QCA at the size scale of molecules, where room-temperature operation is theoretically predicted. This paper reviews QCA theory and the experimental measurements in metal-dot QCA systems, and describes progress toward making QCA molecules and working out surface attachment chemistry compatible with QCA operation.
IEEE Transactions on Nanotechnology, 2004
Quantum-dot cellular automata (QCA) offers a new paradigm for molecular electronics, a paradigm i... more Quantum-dot cellular automata (QCA) offers a new paradigm for molecular electronics, a paradigm in which information transmission and processing depend on electrostatic interactions between charges in arrays of cells composed of quantum dots. Fundamental questions about the operational temperature and functional gain of devices built from molecular-scale QCA cells are addressed in this paper through a statistical-mechanical model based on electrostatic interactions. The model provides exact solutions for the thermodynamic constraints on operation of small arrays of cells (up to 15
We investigate PMMA development at lowered temperatures for its effect on the resolution, PMMA tr... more We investigate PMMA development at lowered temperatures for its effect on the resolution, PMMA trench cleanliness and pattern quality of sub-10 nm e-beam lithography. We find that low temperature development (4∼10 deg. C) results in reproducibly 4∼8 nm PMMA trenches and fabrication of single-particle-width Au nano-particle lines by liftoff. We discuss development temperature and other key factors for formation of better quality PMMA trenches at the sub-10 nm scale.
IEEE Transactions on Nanotechnology, 2005
Electron beam lithography (EBL) patterning of poly(methylmethacrylate) (PMMA) is a versatile tool... more Electron beam lithography (EBL) patterning of poly(methylmethacrylate) (PMMA) is a versatile tool for defining molecular structures on the sub-10-nm scale. We demonstrate lithographic resolution to about 5 nm using a cold-development technique. Liftoff of sub-10-nm Au nanoparticles and metal lines proves that cold development completely clears the PMMA residue on the exposed areas. Molecular liftoff is performed to pattern DNA rafts with high fidelity at linewidths of about 100 nm. High-resolution EBL and molecular liftoff can be applied to pattern Creutz-Taube molecules on the scale of a few nanometers for quantum-dot cellular automata.
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2004
We investigate poly͑methylmethacrylate͒ ͑PMMA͒ development processing with cold developers ͑4 -10... more We investigate poly͑methylmethacrylate͒ ͑PMMA͒ development processing with cold developers ͑4 -10°C͒ for its effect on resolution, resist residue, and pattern quality of sub-10 nm electron beam lithography ͑EBL͒. We find that low-temperature development results in higher EBL resolution and improved feature quality. PMMA trenches of 4 -8 nm are obtained reproducibly at 30 kV using cold development. Fabrication of single-particle-width Au nanoparticle lines was performed by lift-off. We discuss key factors for formation of PMMA trenches at the sub-10 nm scale.
Electron beam lithography patterning of polymethylmethacrylate (PMMA) is a versatile tool for def... more Electron beam lithography patterning of polymethylmethacrylate (PMMA) is a versatile tool for defining molecular structures on the sub-10 nm scale. We demonstrate Lithographic resolution to about 5 om using a cold development technique. Narrow trenches are used to pattern Creutz-Tanbe molecules with resolution to ahout 15 nm. In addition, DNA rafts are patterned with high fidelity at linewidths of about 100 nm. This technique can he applied to molecular patterning in general, and quantum-dot cellular automata (QCA) in particular.
Langmuir, 2003
... and Marya Lieberman*. Department of Chemistry and Biochemistry, University of Notre Dame, Not... more ... and Marya Lieberman*. Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556. Langmuir , 2003, 19 (4), pp 11591167. DOI: 10.1021/la020697x. Publication Date (Web): January 17, 2003. Copyright © 2003 American Chemical Society ...
Applied Physics Letters, 2002
Electron beam lithography was used to make nanometer trenches in thin polymethylmethacrylate (PMM... more Electron beam lithography was used to make nanometer trenches in thin polymethylmethacrylate (PMMA). After development, the wafers were dipped in an aqueous solution of the Creutz-Taube ion [(NH3)5Ru(pyrazine)Ru(NH3)5](o-toluenesulphonate)5 (CT5), and the PMMA was removed with acetone or dichloromethane. Atomic force microscopy and x-ray photoelectron spectroscopy were used to investigate the surface characteristics of wafers after dissolution of the PMMA and to confirm the binding of a monolayer of CT5 molecules on the wafer within the areas delimited by the PMMA trenches. This masking technique has so far been demonstrated to pattern 35 nm lines of a monolayer of CT5 molecules on silicon dioxide.
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2003
Toward the development of a practical molecular computing scheme, certain molecules are thought t... more Toward the development of a practical molecular computing scheme, certain molecules are thought to be able to perform quantum state switching at room temperature ͑for example, digital bit 1 to 0͒. For the implementation of logic functions, these molecules must be arranged on surfaces in a controlled manner. The Creutz-Taube molecule ͓(NH 3 ) 5 Ru(pyrazine)Ru(NH 3 ) 5 ͔ ϫ(o-toluenesulphonate) 5 ͑CT5͒ can be viewed as a two-dot molecule for the purposes of molecular computing. We report here nanopatterning of CT5 molecules through the use of electron-beam lithography ͑EBL͒ and poly͑methylmethacrylate͒ ͑PMMA͒ electron resist. After development of electron-beam modified PMMA films on SiO 2 , trenches with exposed surfaces were formed. These wafers were then soaked in CT5 aqueous solution. Atomic force microscopy and x-ray photoelectron spectroscopy were used to investigate the surface characteristics of wafers after dissolution of the PMMA and to confirm the binding of a monolayer of CT5 molecules on the wafer within the areas delimited by the PMMA trenches. CT5 molecules were deposited as a monolayer with two Ru atoms lying on the SiO 2 surface. 35-nm-wide lines of a monolayer of CT5 molecules on a SiO 2 surface were demonstrated.
Inorganic Chemistry, 2001
... and Marya Lieberman*. Department of Chemistry and Biochemistry, University of Notre Dame, Not... more ... and Marya Lieberman*. Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556. Inorg. Chem. ... This article references 19 other publications. (1) Lowery, MK; Starshak, AJ; Esposito, JN; Krueger, PC; Kenney, ME Inorg. Chem.1965, 4, 128. ...
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Papers by Marya Lieberman