| Hybrid Organic-Inorganic Films Grown Using Molecular Layer Deposition |
Mar 2011 |
15 pages |
| Authors:
Steven M George; COLORADO UNIV AT BOULDER DEPT OF CHEMICAL ENGINEERING
|
 | This short report will first review several MLD systems that have been demonstrated to illustrate the current state-of-the-art. Some new systems will then be introduced to show the diversity of chemistries that can be employed to grow various hybrid organic-inorganic films. Lastly, speculations will be offered on the future prospects for the MLD of hybrid organic-inorganic materials. |
|
| Improved Mechanical Integrity of ALD-Coated Composite Electrodes for Li-Ion Batteries |
Jan 2011 |
4 pages |
| Authors:
Leah A Riley; Andrew S Cavanagh; Steven M George; Se-Hee Lee; Anne C Dillon; COLORADO UNIV AT BOULDER DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| Mechanical properties of MoO3 composite anodes coated with Al2O3 by atomic layer deposition (ALD) were examined using nanoindentation and nanoscratching. Significant improvement in adhesion to the current collector for the ALD-coated MoO3 is observed. This improved adhesion enables enhanced electrical conductivity for these high capacity/high volume expansion materials, suggesting the potential of these coatings for high-energy density Li-ion batteries suitable for vehicular applications. |
|
| Conformal Surface Coatings to Enable High Volume Expansion Li-Ion Anode Materials |
12 Jul 2010 |
8 pages |
| Authors:
Leah A Riley; Andrew S Cavanagh; Steven M George; Yoon S Jung; Yanfa Yan; Se-Hee Lee; Anne C Dillon; NATIONAL RENEWABLE ENERGY LAB GOLDEN CO
|
| An alumina surface coating is demonstrated to improve electrochemical performance of MoO3 nanoparticles as high capacity/ high-volume expansion anodes for Li-ion batteries. Thin, conformal surface coatings were grown using atomic layer deposition (ALD) that relies on self-limiting surface reactions. ALD coatings were tested on both individual nanoparticles and prefabricated electrodes containing conductive additive and binder. The coated and non-coated materials were characterized using transmission electron microscopy, energy-dispersive X-ray spectroscopy, electrochemical ... |
|
| Thermo-Mechanical Properties of Alumina Films Created Using the Atomic Layer Deposition Technique |
Jan 2010 |
11 pages |
| Authors:
David C Miller; Ross R Foster; Shih-Hui Jen; Jacob A Bertrand; Shawn J Cunningham; Arthur S Morris; Yung-Cheng Lee; Steven M George; Martin L Dunn; COLORADO UNIV AT BOULDER DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| Interdigitated humidity sensors with atomic layer deposited (ALD) coatings of aluminum oxide demonstrated no leakage current relative to uncoated sensors stored in the ambient, indicating Al2O3 may be used to limit the effects of H2O and other chemical species in miniaturized mechanical- and electronicdevices. The long term durability of such coatings is not known, but may be predicted from the related material characteristics. The modulus and hardness of Al2O3 were ... |
|
| Importance of Trimethylaluminum Diffusion in Three-Step ABC Molecular Layer Deposition Using Trimethylaluminum, Ethanolamine, and Maleic Anhydride |
Jan 2010 |
8 pages |
| Authors:
Dragos Seghete; Robert A Hall; Byunghoon Yoon; Steven M George; COLORADO UNIV AT BOULDER DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| Hybrid organic-inorganic films were grown by molecular layer deposition (MLD) with a three-step ABC reaction sequence using (A) trimethylaluminum (TMA), (B) ethanolamine (EA), and (C) maleic anhydride (MA) at 90 oC. Very large steady state mass gains of 1854-4220 ng/(cm2 cycle) were measured depending on reaction conditions. These mass gains are much larger than typical mass gains for surface reactions. The quartz crystal microbalance (QCM) mass profiles during the TMA ... |
|
| Ultrathin Direct Atomic Layer Deposition on Composite Electrodes for Highly Durable and Safe Li-Ion Batteries |
Jan 2010 |
6 pages |
| Authors:
Yoon Seok Jung; Andrew S Cavanagh; Leah A Riley; Sun-Ho Kang; Anne C Dillon; Markus D Groner; Steven M George; Se-Hee Lee; COLORADO UNIV AT BOULDER
|
| In order to employ Li-ion batteries (LIBs) in next-generation hybrid electric and/or plug-in hybrid electric vehicles (HEVs and PHEVs), LIBs must satisfy many requirements: electrodes with long lifetimes (fabricated from inexpensive environmentally benign materials), stability over a wide temperature range, high energy density, and high rate capability. Establishing long-term durability while operating at realistic temperatures (5000 charge-depleting cycles, 15 year calendar life, and a range from -46 deg C to ... |
|
| Molecular Layer Deposition of Hybrid Organic-Inorganic Alucone Polymer Films Using a Three-Step ABC Reaction Sequence |
02-Nov-2009 |
11 pages |
| Authors:
Steven M George; Byunghoon Yoon; Dragos Seghete; Andrew S Cavanagh; COLORADO UNIV AT BOULDER
|
| Thin film growth using molecular layer deposition (MLD) or atomic layer deposition (ALD) is based on sequential, self-limiting surface reactions. In this work, MLD is used to grow a hybrid organic-inorganic polymer film based on a three-step ABC reaction sequence using trimethylaluminum (TMA), ethanolamine (EA), and maleic anhydride (MA) as the reactants. This three-step ABC sequence avoids the use of homobifunctional organic precursors by employing a homotrifunctional inorganic reactant (TMA), ... |
|
| Atomic Layer Deposition on Gram Quantities of Multi-Walled Carbon Nanotubes |
03 Jun 2009 |
12 pages |
| Authors:
Andrew S Cavanaugh; Christopher A Wilson; Alan W Weimer; Steven M George; COLORADO UNIV AT BOULDER DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| Atomic layer deposition (ALD) was employed to grow coaxial thin films of Al2O3 and Al2O3/W bilayers on multi-walled carbon nanotubes (MWCNTs). Although the MWCNTs have an extremely high surface area, a rotary ALD reactor was successfully employed to perform ALD on gram quantities of MWCNTs. The uncoated and ALD-coated MWCNTs were characterized with transmission electron microscopy and x-ray photoelectron spectroscopy. Al2O3 ALD on untreated MWCNTs was characterized by nucleation difficulties ... |
|
| Atomic Layer Deposition Enabled Interconnect Technology for Vertical Nanowire Arrays |
Jun 2009 |
26 pages |
| Authors:
Jen-Hau Cheng; Dragos Seghete; Myongjai Lee; John B Schlager; Kris A Bertness; Norman A Sanford; Ronggui Yang; Steven M George; Y C Lee; COLORADO UNIV AT BOULDER DEPT OF MECHANICAL ENGINEERING
|
| We have demonstrated an atomic layer deposition (ALD) enabled interconnect technology for vertical, c-axis oriented gallium nitride (GaN) nanowire (NW, 5-10 um in length, 80-200 nm in diameter) arrays encapsulated by Benzocyclobutene (BCB). The nano-scaled ALD multilayer is essential to provide conformal co-axial dielectric (ALDalumina)/ conductor (ALD-tungsten) coverage and precise thickness control for nanowire metallization. Furthermore, we have successfully developed a fabrication process to locally remove and connect tungsten (W) ... |
|
| Fabrication of Nanolaminates with Ultrathin Nanolayers Using Atomic Layer Deposition: Nucleation & Growth Issues |
Feb-2009 |
36 pages |
| Authors:
Steven M George; COLORADO UNIV AT BOULDER DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| This AFOSR grant concentrated on the fabrication of nanolaminates with ultrathin nanolayers using atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques. Nanolaminates are multilayered thin film structures with nanometer dimensions and very high interfacial density. These multilayer structures can display novel properties that can be optimized by manipulating the thickness and composition of the individual nanolayers. During this grant, the research examined nucleation and growth issues involved in ... |
|
| Thermomechanical Properties of Aluminum Alkoxide (Alucone) Films Created Using Molecular Layer Deposition |
Jan 2009 |
12 pages |
| Authors:
David C Miller; Ross R Foster; Shih-Hui Jen; Jacob A Bertrand; Dragos Seghete; Byunghoon Yoon; Yung-Cheng Lee; Steven M George; Martin L Dunn; COLORADO UNIV AT BOULDER DEPT OF MECHANICAL ENGINEERING
|
| Nanometer-scale-thick, polymer-like coatings deposited using the molecular layer deposition (MLD) technique constitute a new class of materials. The modulus and hardness of aluminum alkoxide (alucone) films grown using either homobifunctional or heterobifunctional reactants were measured using nanoindentation. Because the coatings are brittle and possess a significant tensile film stress immediately after deposition, the influence of film stress on the indentation measurements was quantified using a numerical analysis protocol. The film ... |
|
| Micromachined Resonators of High Q-factor Based on Atomic Layer Deposited Alumina |
Jan 2009 |
10 pages |
| Authors:
Yuan-Jeng Chang; Jason M Gray; Atif Imtiaz; Dragos Seghete; T M Wallis; Steven M George; Pavel Kabos; CHARLES T ROGERS; Victor M Bright; COLORADO UNIV AT BOULDER DEPT OF MECHANICAL ENGINEERING
|
| In this paper, atomic layer deposited (ALD) alumina (Al2O3) has been demonstrated as the structural material for a micro-resonator for the first time. An electrostatically actuated micro-bridge made of chromium (Cr) coated ALD Al2O3 was used as a resonator. The resonatorwas formed by simplewet- and dry-etching processes. The static displacement profile of the micro-resonator under electrostatic load was measured by an optical interferometer. A model of a pinned?pinned beam with ... |
|
| Protection of Polymer from Atomic-Oxygen Erosion using Al2O3 Atomic Layer Deposition Coatings |
Jan-2008 |
5 pages |
| Authors:
Russell Cooper; Timothy K Minton; Steven M George; Hari P Upadhyaya; Michael R Berman; Xiaohua Du; MONTANA STATE UNIV BOZEMAN DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| Thin films of Al2O3 grown using atomic layer deposition (ALD) techniques can protect polymers from erosion by oxygen atoms. To quantify this protection, polyimide substrates with the same chemical repeat unit as Kapton (registered trademark) were applied to quartz crystal microbalance (QCM) sensors. Al2O3 ALD films with varying thicknesses were grown on the polyimide substrates. The ALD-coated polyimide materials were then exposed to a hyperthermal atomic-oxygen beam. The mass loss ... |
|
| X-Ray Mirrors on Flexible Polymer Substrates Fabricated by Atomic Layer Deposition |
18 Sep 2006 |
5 pages |
| Authors:
Francois H Fabreguette; Steven M George; COLORADO UNIV AT BOULDER DEPT OF CHEMISTRY
|
| Atomic layer deposition (ALD) techniques were used to fabricate W/Al2O3 superlattices with high X-ray reflectivity on flexible Kapton polyimide and polyethylene naphthalate (PEN) polymer substrates. Reflectivities of 78% and 74% at A=1.54 were measured for 6-bilayer W/ Al2O3 superlattices on Kapton polyimide and PEN, respectively. These excellent X-ray reflectivities are attributed to precise bilayer thicknesses and ultrasmooth interfaces obtained by ALD and smoothing of the initial polymer surface by an ... |
|
| Alternative Dielectric Films for rf MEMS Capacitive Switches Deposited using Atomic Layer Deposited Al2O3/ZnO Alloys |
02 Jul 2006 |
12 pages |
| Authors:
Cari F Herrman; Frank W DelRio; David C Miller; Steven M George; Victor M Bright; Jack L Ebel; Richard E Strawser; Rebecca Cortez; Kevin D Leedy; COLORADO UNIV AT BOULDER DEPT OF MECHANICAL ENGINEERING
|
| Atomic layer deposition (ALD) was used to deposit an alternative dielectric barrier layer for use in radio frequency microelectromechanical systems (rf MEMS). The layer is an alloy mixture of Al2O3 and ZnO and is proposed for use as charge dissipative layers in which the dielectric constant is significant enough to provide a large down-state capacitance while the resistivity is sufficiently low to promote the dissipation of trapped charges. This paper ... |
|
Reports by Author
