Now showing items 21-36 of 36

    • Influence of Growth Temperature on Bulk and Surface Defects in Hybrid Lead Halide Perovskite Films 

      Peng, Weina; Anand, Benoy; Liu, Lihong; Sampat, Siddharth; Bearden, Brandon E.; Malko, Anton V.; Chabal, Yves J. (Royal Society of Chemistry, 2015-12-14)
      The rapid development of perovskite solar cells has focused its attention on defects in perovskites, which are gradually realized to strongly control the device performance. A fundamental understanding is therefore needed ...
    • Structural, Elastic, Thermal, and Electronic Responses of Small-Molecule-Loaded Metal-Organic Framework Materials 

      Canepa, Pieremanuele; Tan, Kui; Du, Yingjie; Lu, Hongbing; Chabal, Yves J.; Thonhauser, Timo
      We combine infrared spectroscopy, nano-indentation measurements, and ab initio simulations to study the evolution of structural, elastic, thermal, and electronic responses of the metal-organic framework MOF-74-Zn when ...
    • Structural Band-Gap Tuning in g-C₃N₄ 

      Zuluaga, S.; Liu, Li-Hong; Shafiq, Natis; Rupich, Sara M.; Veyan, Jean-François; Chabal, Yves J.; Thonhauser, T.
      g-C3N4 is a promising material for hydrogen production from water via photo-catalysis, if we can tune its band gap to desirable levels. Using a combined experimental and ab initio approach, we uncover an almost perfectly ...
    • Structural Band-Gap Tuning in g-C₃N₄ 

      Zuluaga, S.; Liu, Li-Hong; Shafiq, Natis; Rupich, Sara M.; Veyan, Jean-François; Chabal, Yves J.; Thonhauser, T.
      g-C₃N₄ is a promising material for hydrogen production from water via photo-catalysis, if we can tune its band gap to desirable levels. Using a combined experimental and ab initio approach, we uncover an almost perfectly ...
    • Water Interactions In Metal Organic Frameworks 

      Tan, Kui; Nijem, Nour; Gao, Yuzhi; Zuluaga, S.; Li, J.; Thonhauser, T.; Chabal, Yves J.
      Metal organic frameworks (MOFs) have a strong potential for gas adsorption and separation such as H2 and CH4 storage, and CO2 capture. However, their instability in the presence of water vapor (many MOFs are hygroscopic) ...
    • Effective Sensing of RDX via Instant and Selective Detection of Ketone Vapors 

      Hu, Zhichao; Tan, Kui; Lustig, William P.; Wang, Hao; Zhao, Yonggang; Zheng, Chong; Banerjee, Debasis; Emge, Thomas J.; Chabal, Yves J.; Li, Jing
      Two new luminescent metal-organic frameworks (LMOFs) were synthesized and examined for use as sensory materials. Very fast and effective sensing of RDX was achieved by vapor detection of a cyclic ketone used as a solvent ...
    • Morphology and Chemical Termination of HF-Etched Si₃N₄ Surfaces 

      Liu, Li-Hong; Debenedetti, William J. I.; Peixoto, Tatiana; Gokalp, Sumeyra; Shafiq, Natis; Veyan, Jean-François; Michalak, D. J.; Hourani, R.; Chabal, Yves J.
      Several reports on the chemical termination of silicon nitride films after HF etching, an important process in the microelectronics industry, are inconsistent claiming N-Hx, Si-H, or fluorine termination. An investigation ...
    • Lowering the Density of Electronic Defects on Organic-Functionalized Si(100) Surfaces 

      Peng, Weina; DeBenedetti, William J. I.; Kim, Seonjae; Hines, Melissa A.; Chabal, Yves J.
      The electrical quality of functionalized, oxide-free silicon surfaces is critical for chemical sensing, photovoltaics, and molecular electronics applications. In contrast to Si/SiO₂ interfaces, the density of interface ...
    • Selectivity of Metal Oxide Atomic Layer Deposition on Hydrogen Terminated and Oxidized Si(001)-(2x1) Surface 

      Longo, Roberto C.; McDonnell, Stephen; Dick, D.; Wallace, Robert M.; Chabal, Yves J.; Owen, James H. G.; Ballard, Josh B.; Randall, John N.; Cho, Kyeongjae (A V S Amer Inst Physics, 2014-02-10)
      In this work, the authors used density-functional theory methods and x-ray photoelectron spectroscopy to study the chemical composition and growth rate of HfO₂, Al₂O₃, and TiO₂ thin films grown by in-situ atomic layer ...
    • Energy Transfer from Colloidal Nanocrystals into Si Substrates Studied via Photoluminescence Photon Counts and Decay Kinetics 

      Nguyen, H. M.; Seitz, Oliver; Gartstein, Yuri N.; Chabal, Yves J.; Malko, Anton V. (2013-08-16)
      We use time-resolved photoluminescence (PL) kinetics and PL intensity measurements to study the decay of photoexcitations in colloidal CdSe/ZnS nanocrystals grafted on SiO₂ - Si substrates with a wide range of the SiO₂ ...
    • Diffusion of Small Molecules in Metal Organic Framework Materials 

      Canepa, Pieremanuele; Nijem, Nour; Chabal, Yves J.; Thonhauser, T.
      Ab initio simulations are combined with in situ infrared spectroscopy to unveil the molecular transport of H-2, CO2, and H2O in the metal organic framework MOF-74-Mg. Our study uncovers-at the atomistic level-the major ...
    • Structure Matters: Correlating Temperature Dependent Electrical Transport Through Alkyl Monolayers With Vibrational And Photoelectron Spectroscopies 

      Shpaisman, Hagay; Seitz, Oliver; Yaffe, Omer; Roodenko, Ecatherina (Katy); Scheres, Luc; Zuilhof, Han; Chabal, Yves J.; Sueyoshi, Tomoki; Kera, Satoshi; Ueno, Nobuo; Vilan, Ayelet; Cahen, David
      Freezing out of molecular motion and increased molecular tilt enhance the efficiency of electron transport through alkyl chain monolayers that are directly chemically bound to oxide-free Si. As a result, the current across ...
    • Colored Porous Silicon as Support for Plasmonic Nanoparticles 

      Lublow, M.; Kubala, S.; Veyan, Jean-Francois; Chabal, Yves J.
      Colored nanoporous silicon thin films were employed as dielectric spacing layers for the enhancement of localized surface plasmon (LSP) polaritons. Upon formation of Au nanoparticles (Au-NPs) on these layers, a visible ...
    • Investigation of LiAlH 4-THF Formation by Direct Hydrogenation of Catalyzed Al and LiH 

      Lacina, D.; Yang, L.; Chopra, Irinder; Muckerman, J.; Chabal, Yves J.; Graetz, J.
      The formation of LiAlH 4-THF by direct hydrogenation of Al and LiH in tetrahydrofuran (THF) was investigated using spectroscopic and computational methods. The molecular structures and free energies of the various possible ...
    • Characterization of Ru Thin-Film Conductivity upon Atomic Layer Deposition on H-Passivated Si(111) 

      Roodenko, Ecatherina (Katy); Park, S. K.; Kwon, Jinhee; Wielunski, L.; Chabal, Yves J.
      The sheet resistance measured by a four-probe technique is compared to the resistivity data derived from the optical response of thin ruthenium films grown on hydrogen-passivated Si(111) surfaces by atomic-layer deposition ...
    • Wet chemical surface functionalization of oxide-free silicon 

      Thissen, Peter; Seitz, Oliver; Chabal, Yves J. (Elsevier Limited, 2012-09-13)
      Silicon is by far the most important semiconductor material in the microelectronic industry mostly due to the high quality of the Si/SiO2 interface. Consequently, applications requiring chemical functionalization of Si ...