Customer Papers
This is a searchable database of papers written by our customers, using Cambridge NanoTech systems. If you are publishing a paper based on research done on a Cambridge NanoTech ALD system, please contact us. We would be pleased to include it in our database.Showing customer papers 1-10 of 87 Next
| LINK | Bielawny, A.; Upping, J.; Miclea, P. T.; Wehrspohn, R. B.; Rockstuhl, C.; Lederer, F.; Peters, M.; Steidl, L.; Zentel, R.; Lee, S. M.; Knez, M.; Lambertz, A.; Carius, R. |
| "3D photonic crystal intermediate reflector for micromorph thin-film tandem solar cell" | |
| Physica Status Solidi a-Applications and Materials Science, 2008, 205, 2796-2810 | |
| Abstract: | The concept of 3D photonic intermediate reflectors for micromorph silicon tandem solar cells has been investigated. In thin-film silicon tandem solar cells consisting of amorphous and microcrystalline silicon with two junctions of a-Si/mu c-Si, efficiency enhancements can be achieved by increasing the current density in the a-Si top cell. It is one goal to provide an optimized current matching at high current densities. For an ideal photon-management between top and bottom cell, a spectrally selective intermediate reflective layer (IRL) is necessary, which is less dependent of the angle of incidence than state-of-the-art thickness dependent massive interlayers. The design, preparation and characterization of a 3D photonic thin-film filter device for this purpose has been pursued straight forward in simulation and experimental realization. The inverted opal is, capable of providing a suitable optical band stop with high reflectance and the-necessary long wavelength transmittance as well and provides further options\' for improved light trapping. We have determined numerically the relative: efficiency enhancement of an a-Si/mu c-Si tandem solar cell using a conductive 3D-photonic crystal. We have further fabricated such structures by ZnO-replication of polymeric opals using chemical vapour deposition and atomic layer deposition techniques and present the results of their characterization. Thin film photonic IRL have been prepared at the rear side of a-Si solar cells. Completed with a back contact, this is the first step to integrate this novel technology into an a-Si/mu c-Si tandem solar cell process. The spectral response of the cell is presented and compared with reference cells. (C) 2008 WILEY-VCH Verlag GmbH |
| Address: | Bielawny, A Univ Halle Wittenberg, Inst Phys, UMD Grp, Heinrich Damerow Str 4, D-06120 Halle, Germany Univ Halle Wittenberg, Inst Phys, UMD Grp, Heinrich Damerow Str 4, D-06120 Halle, Germany Univ Halle Wittenberg, Inst Phys, UMD Grp, D-06120 Halle, Germany Univ Jena, Inst Condensed Matter Theory |
| LINK | Chang, C. Y.; Tsai, F. Y.; Jhuo, S. J.; Chen, M. J. |
| "Enhanced OLED performance upon photolithographic patterning by using an atomic-layer-deposited buffer layer" | |
| Organic Electronics, 2008, 9, 667-672 | |
| Abstract: | This study addresses the problem of patterning-induced degradations to organic light-emitting diodes (OLEDs) by using a thin (10 A) atomic-layer-deposited (ALD) A(2)O(3) film as both an electron-injection layer and a protecting layer for the electroluminescent material, poly[1-metlioxy-4-(2\'-ethyl-hexyloxy)-2,5-plienylene vinylene] (MEH-PPV). With the ALD Al2O3 film, the OLEDs not only withstood an aggressive photolithographic patterning process without any degradation but unprecedentedly showed increased luminous efficiency (by 100%) and lowered turn-on voltage (by 19%) afterward. Although the ALD precursor, trimethylaluminum (TMA), was found to damage the MEH-PPV layer through electrophilic addition to the vinylene groups of MEH-PPV during the deposition of the Al2O3 film, its damaging effect was eliminated by pre-treating the MEH-PPV surface with isopropyl alcohol (IPA), whose hydroxyl groups scavenged TMA throughout the ALD process. The performance of the photo-patterned OLEDs was further improved by using a high-conductivity hole-injection layer, which increased accumulation of holes at the EL-buffer interface to enhance electron injection. The method reported herein improves the applicability of photolithography to OLED fabrication, promising to resolve the issue of patterning that has in part impeded OLED\'s commercialization. (C) 2008 Elsevier B.V. All rights reserved. |
| Address: | Tsai, FY Natl Taiwan Univ, Dept Mat Sci |
| LINK | Ding, Y.; Xu, S.; Zhang, Y.; Wang, A. C.; Wang, M. H.; Xiu, Y. H.; Wong, C. P.; Wang, Z. L. |
| "Modifying the anti-wetting property of butterfly wings and water strider legs by atomic layer deposition coating: surface materials versus geometry" | |
| Nanotechnology, 2008, 19, - | |
| Abstract: | Although butterfly wings and water strider legs have an anti-wetting property, their working conditions are quite different. Water striders, for example, live in a wet environment and their legs need to support their weight and bear the high pressure during motion. In this work, we have focused on the importance of the surface geometrical structures in determining their performance. We have applied an atomic layer deposition technique to coat the surfaces of both butterfly wings and water strider legs with a uniform 30 nm thick hydrophilic Al2O3 film. By keeping the surface material the same, we have studied the effect of different surface roughness/structure on their hydrophobic property. After the surface coating, the butterfly wings changed to become hydrophilic, while the water strider legs still remained super-hydrophobic. We suggest that the super-hydrophobic property of the water strider is due to the special shape of the long inclining spindly cone-shaped setae at the surface. The roughness in the surface can enhance the natural tendency to be hydrophobic or hydrophilic, while the roughness in the normal direction of the surface is favorable for forming a composite interface. |
| Address: | Wang, ZL Georgia Inst Technol, Sch Mat Sci |
| LINK | Hamann, T. W.; Martinson, A. B. E.; Elam, J. W.; Pellin, M. J.; Hupp, J. T. |
| "Aerogel templated ZnO dye-sensitized solar cells" | |
| Advanced Materials, 2008, 20, 1560- | |
| Abstract: | Atomic layer deposition is employed to conformally coat low density, high surface area aerogel films with ZnO. The ZnO/aerogel membranes are incorporated as photoanodes in dye-sensitized solar cells, which exhibit excellent power efficiencies of up to 2.4% under 100 mW cm(-2) light intensity. |
| Address: | Hupp, JT Northwestern Univ, 2145 Sheridan Rd, Evanston, IL 60208 USA Northwestern Univ, 2145 Sheridan Rd, Evanston, IL 60208 USA Northwestern Univ, Evanston, IL 60208 USA Argonne Natl Lab, Argonne, IL 60439 USA |
| LINK | Huang, J. Y.; Wang, X. D.; Wang, Z. L. |
| "Bio-inspired fabrication of antireflection nanostructures by replicating fly eyes" | |
| Nanotechnology, 2008, 19, - | |
| Abstract: | In this study, we examined the fine structure of the compound eyes of a household fly and precisely replicated its entire structure using a low-temperature atomic layer deposition technique. The surface of the fly eye is found to be covered by highly packed protuberances, which potentially increases visual efficiency through increased photon capture for a given stimulus. The alumina replica was achieved by removing the fly compound eye template at high temperature, and the alumina coating was crystallized simultaneously. Besides the morphology, the unique antireflection property was also inherited by the alumina replica. By measuring the reflective spectra of the replica, we demonstrated that the alumina replica of a fly eye was an efficient antireflection structure of visible light at an incident angle up to 80 degrees. Such a grating would be particularly useful on a cured corneal surface since it could increase the transmission of incident light through the cornea compared with a smooth surface. |
| Address: | Huang, JY Georgia Inst Technol, Sch Mat Sci |
| LINK | Kim, G. M.; Lee, S. M.; Michler, G. H.; Roggendorf, H.; Gosele, U.; Knez, M. |
| "Nanostructured pure anatase titania tubes replicated from electrospun polymer fiber templates by atomic layer deposition" | |
| Chemistry of Materials, 2008, 20, 3085-3091 | |
| Abstract: | Pure anatase TiO2 submicrotubes were successfully fabricated by a template-directed method. Electrospun poly(vinyl pyrrolidone) (PVP) fibers were used as a soft template for coating with titanium dioxide using an atomic layer deposition (ALD) technique. The deposition was conducted onto a template at 70 degrees C by using titanium tetraisopropyl oxide (TIP) [Ti((OPr)-Pr-i)(4)] and pure water as precursors of TiO2. Crystalline structure, microstructure, and optical properties of the TiO2 deposited layers before and after calcination were studied in detail. While the as-deposited TiO2 layers onto ES fibers were completely amorphous with thickness of about 60 nm, the TiO2 layers after calcination at 500 degrees C for 4 h were properly converted into polycrystalline nanostructured TiO2 submicrotubes with high quality of anatase. Thereby, the optical band gap energy was also tuned with a blue shift. As final products the self-supported free-standing mats consisting of pure anatase TiO2 submicrotubes can be easily handled and reclaimed for use in future applications related to catalysis, electronics, photonics, sensing, medicine, and controlled drug release. |
| Address: | Kim, GM Univ Halle Wittenberg, Inst Phys, D-06099 Halle, Germany Univ Halle Wittenberg, Inst Phys, D-06099 Halle, Germany Univ Halle Wittenberg, Inst Phys, D-06099 Halle, Germany Max Planck Inst Microstruct Phys, D-06120 Halle S, Germany |
| LINK | Lee, B.; Choi, K. J.; Hande, A.; Kim, M. J.; Wallace, R. M.; Kim, J.; Senzaki, Y.; Shenai, D.; Li, H.; Rousseau, M.; Suydam, J. |
| "A novel thermally-stable zirconium amidinate ALD precursor for ZrO2 thin films" | |
| Microelectronic Engineering, 2009, 86, 272-276 | |
| Abstract: | ZrO2 thin films were deposited by the atomic layer deposition process on Si substrates using tetrakis(N,N\'-dimethylacetamidinate) zirconium (Zr-AMD) as a Zr precursor and H2O as an oxidizing agent. Tetrakis (ethylmethylamino) zirconium (TEMA-Zr) was also evaluated for a comparative study. Physical properties of ALD-derived ZrO2 thin films were studied using ellipsometry, grazing incidence XRD (Gl-XRD), high resolution TEM (HRTEM), and atomic force microscopy (AFM). The ZrO2 deposited using Zr-AMD showed a better thermal stability at high substrate temperature (>300 IQ compared to that using TEMA-Zr. GI-XRD analysis reveals that after 700 degrees C anneal both ZrO2 films enter tetragonal phase. The electrical properties of N-2-annealed ZrO2 film using Zr-AMD exhibit all EOT of 1.2 nm with leakage current density as low as 2 x 10(-3) A/cm(2) (@V-(sic)-1 V). The new Zr amidinate is a promising ALD precursor for high-k dielectric applications. (C) 2008 Elsevier B.V. All rights reserved. |
| Address: | Kim, J Univ Texas Dallas, Richardson, TX 75083 USA Univ Texas Dallas, Richardson, TX 75083 USA Univ Texas Dallas, Richardson, TX 75083 USA Rohm |
| LINK | Lee, B. K.; Park, S. Y.; Kim, H. C.; Cho, K.; Vogel, E. M.; Kim, M. J.; Wallace, R. M.; Kim, J. Y. |
| "Conformal Al2O3 dielectric layer deposited by atomic layer deposition for graphene-based nanoelectronics" | |
| Applied Physics Letters, 2008, 92, - | |
| Abstract: | We present a facile route which combines the functionalization of a highly oriented pyrolytic graphite surface with an atomic layer deposition (ALD) process to allow for conformal Al2O3 layers. While the trimethylaluminum (TMA)/H2O process caused selective deposition only along step edges, the TMA/O-3 process began to provide nucleation sites on the basal planes of the surface. O-3 pretreatment, immediately followed by the ALD process with TMA/O-3 chemistry, formed Al2O3 layers without any preferential deposition at the step edges. This is attributed to functionalization of graphene by ozone treatment, imparting a hydrophilic character which is desirable for ALD deposition. (C) 2008 American Institute of Physics. |
| Address: | Kim, JY Univ Texas Dallas, Dept Mat Sci |
| LINK | Yang, Y.; Kim, D. S.; Knez, M.; Scholz, R.; Berger, A.; Pippel, E.; Hesse, D.; Gosele, U.; Zacharias, M. |
| "Influence of temperature on evolution of coaxial ZnO/Al2O3 one-dimensional heterostructures: From core-shell nanowires to spinel nanotubes and porous nanowires" | |
| Journal of Physical Chemistry C, 2008, 112, 4068-4074 | |
| Abstract: | In this paper, we present the influence of temperature on the Kirkendall effect-related evolution of coaxial ZnO/Al2O3 one-dimensional heterostructures based on a solid-state reaction. Controllable fabrication of spinel ZnAl2O4-based nanotubes and porous nanowires can step-by-step be achieved from ZnO/Al2O3 core-shell nanowires with a change in the reaction temperature. In particular, we demonstrate that the formation of completely hollow nanotubes in this system is not strictly limited to a fixed stoichiometry of ZnO/Al2O3 required for the spinel-forming reaction when an annealing temperature of 800 degrees C is employed. Combined with atomic layer deposition, the wall thickness of the formed nanotubes can be further precisely tailored and defined. Our finding provides an effective route to fabricate spinel nanotubes as well as nanotube arrays on a large scale. |
| Address: | Yang, Y Max Planck Inst Microstruct Phys, Weinberg 2, D-06120 Halle, Germany Max Planck Inst Microstruct Phys, Weinberg 2, D-06120 Halle, Germany Max Planck Inst Microstruct Phys, D-06120 Halle, Germany Univ Freiburg, Fac Sci Appl, IMTEK, D-79110 Freiburg, Germany |
| LINK | Zhang, X. H.; Lee, S. M.; Domercq, B.; Kippelen, B. |
| "Transparent organic field-effect transistors with polymeric source and drain electrodes fabricated by inkjet printing" | |
| Applied Physics Letters, 2008, 92, - | |
| Abstract: | Transparent organic field-effect transistors based on pentacene were fabricated on indium tin oxide (ITO)-coated glass using ITO as the gate electrode, Al2O3 grown by atomic layer deposition as the gate insulator, and an inkjet-printed conducting polymer poly(3,4-ethylenedioxythiophene):poly(4-styrenesulphonate) as the source and drain electrodes. The transistors combine an overall high transmittance (84% in the channel and 78% through source/drain electrodes) in the visible region, a field-effect mobility value of 0.3 cm(2)/V s, a threshold voltage of -0.2 V, a subthreshold slope of 0.9 V/decade, and an on/off current ratio of 10(5). (c) 2008 American Institute of Physics. |
| Address: | Kippelen, B Georgia Inst Technol, Sch Elect |
Showing customer papers 1-10 of 87 Next