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 graduate students

Wilfredo Cabrera

cabreraCurrently, I am a third year graduate student working under the supervision of Dr. Yves Chabal. My work focuses on the atomic layer deposition (ALD) of higher-? dielectrics, particularly Al2O3 and HfO2, on III-V materials. Using various characterization techniques, such as FTIR, XPS, LEIS, AFM, and ellipsometry, we can look at the different properties of the materials being deposited. Currently, I am part of a team that has built a cluster tool combining insitu XPS, FTIR, and LEIS to study surface chemistry and elemental diffusion through high-k oxides. A large part of my work has concentrated on the influence of surface preparations on the growth mechanisms of Al2O3, HfO2, and silicates on InP(100) by using a home-built ALD chamber equipped with in-situ FTIR. Also, the effects of various wet chemical preparations on the surface prior to ALD, temperature dependence on the ALD growth of higher-?, effects of various oxidizing agents on the growth mechanisms, and post ALD growth treatments. On a side note, I obtained my bachelor's degree from the University of Nebraska at Kearney, where I worked on temperature-concentration dependence range of nematic phase transformation of IR-806 under the supervision of Dr. Liubov Kreminska. When I am not spending my time at the lab, I am taking part in various sports and trying to refine my skills on the guitar.

Louis Caillard

caillardAs a PhD candidate in Professor Yves Chabal's lab, I work on silicon surface modification with organic materials for device application. I work on two different projects: -chemical attachment of amine terminated short molecule on oxide free Si(111) for the grafting of gold nanoparticles. This structure, with the use of an STM, allows us to observe single electron transport (coulomb staircase). We plan to make prototypes of single electron transistor using this type of architecture. This work is a collaboration between the university of Texas at Dallas (UTD) and "université Pierre et Marie curie" (UPMC) in Paris -functionalization of oxide free Si(111) and SiO2 surface with an amine terminated molecule for the attachment of layers of Nano-quantum dots. These can be used in the framework of photovoltaic cells application to harvest a wide spectrum of the incoming light and transfer it to the underlying silicon. Silicon patterning (nanopillars) has also been used to increase surface area to achieve a better efficiency. I am familiar with a wide variety of fabrication (wet chemistry, nanosphere lithography, UV lithography, metal deposition, plasma etching,…) and characterization techniques ( XPS, FTIR, SEM, TEM, STM, AFM, ellipsometry, …). I graduated from the Master Nanotech, joint program between "Grenoble INP" in France, "Politecnico di Torino" in Italy and "EPF Lausanne" in Switzerland. My background is based on physics for nanoscience and micro and nano electronics. I also performed an internship in Korea University in Seoul and in the Massachusetts institute of Technology (MIT) where I worked on the self assembly of gold particle on patterned surface.

Don Dick

dickI am working towards getting my PhD in Materials Physics. Currently I am working on Atomically precise ALE growth; which will lead to 3D control of semiconductor growth. I will also start working with Irinder on hydrogen storage via complex metal hydrides.
I have tried working with other research groups such as particle physics and condensed matter theory, but they didn’t have the working environment I was looking for. I enjoy working hands on; which I’ve found to mean, working with small experiments.
I represent the more indigenous side of the group; I was born and raised in the Houston/Galveston area of Texas. I am an avidly mediocre guitarist.

Tatiana Peixoto

peixotoTechnology constantly searches to improve its processes and discover materials to optimize devices. In this regard, the presence of nitrogen containing molecules on the surface offers diversity in electrical applications for devices (dielectric layer, photovoltaics) and sensors (protein attachment). Present deposition techniques for such layers use expensive techniques that are time intensive, but for industry time is money, and my project tries to save on both fronts. As a fourth year Materials Science PhD student working under Prof. Chabal, my project involves the use of wet-chemistry to study the attachment, behavior, and formation of silylamines on modified, oxide-free Si(111) surfaces. My work studies particularly the similarities and differences in attachment and behavior of solution and liquid ammonia and liquid ethylenediamine with the modified silicon. These surfaces are studied using Fourier-Transformed Infrared (FTIR) showing the attachment configuration, Atomic Force Microscopy (AFM) for imaging of the surface, and X-ray Photoelectron Spectroscopy (XPS) for elucidation of the chemical environment and attachment.
My future aim is to apply my learning and experience to an industrial research environment. I discovered how much I enjoyed researching, during my two year internship with 3M working on corrosion protection coatings of pipelines, while pursuing my bachelors degree from the University of Texas at Austin. Apart from work, I am a fun loving, lively person with interests in playing music, staying outdoors, volunteering and experimenting with cooking.

Karla Bernal Ramos

ramosI received my degree in Chemical Engineering in 2008 from the Universidad Autonoma de Coahuila (Mexico). I joined Prof. Chabal's group in 2009 as a PhD student in the Material Science and Engineering (MSEN) program. I received my master degree in MSEN in 2011 and hopefully will obtain my PhD degree in summer 2014. My main research focused on the growth of metal oxides (TiO2, Al2O3, SnO2), metals (Co, Mn, W) and metal nitrides (WNx layer deposition (ALD), a powerful technique that can deliver highly conformal films. We use in- situ Fourier transform infrared (FTIR) spectroscopy in order to obtain mechanistic information of the reactions taking place during the process. Studies of the growth mechanisms during film deposition are critical to better understand and control thin film formation and can best be performed using in-situ characterization techniques.
(1) Karla Bernal Ramos, G. Clavel, C. Marichy, W. Cabrera, N. Pinna, Y. J. Chabal. Chem. Mater.25 (9), 1706–1712 (2013)
(2) Karla Bernal Ramos, Mark J. Saly and Yves J. Chabal. Coordination Chemistry Reviews 257, 3271–3281 (2013)

Kui Tan

09/2004-07/2008 B.S. in Materials Chemistry, College of Chemistry, Nankai University, China
08/2008-till now First year
Ph.D. Candidate in Materials Science and Engineering, The University of Texas at Dallas

Prof. Peng Cheng’s lab Design and synthesis of metal-organic frameworks based on the triazole and their derivates for hydrogen storage and further investigate their crystal structures, properties. 

Abraham Vega

Abraham VegaMy name is Abraham Vega and I am currently a Ph.D. candidate. I am a Research Assistant in Professor Chabal's group and have a Bachelor in Mechatronic Engineering from the Instituto Tecnológico de Saltillo in Mexico. My research focuses on the modification of semiconductor surfaces to enhance its properties. I am currently working on two projects; the first one consists in the growth and characterization of silicon nitride by Atomic Layer Deposition (ALD) which is becoming of great importance to increase the performance and reliability of conventional silicon oxide gate oxides. The second one is Monolayer doping (MLD), a promising technique for creating ultra-shallow junctions, this technique provides uniform coverage of a specific quantity of dopant containing molecules and high temperature anneals drive the dopant atoms into the semiconductor via diffusion mechanism, making possible to get abrupt and shallow junctions, of great importance for the continuous device scaling.

Yuzhi Gao

Yuzhi GaoI am a first year graduate student in Materials Science and Engineering at The University of Texas at Dallas, under the supervision of Prof. Yves J. Chabal. I earned my bachelor degree in Behang University and received my master degree in University of Pennsylvania before I moved to Dallas. Before coming to UTD, I have done research on plasmonic materials synthesis and ceramics microstructure characterization. Currently, I am working on understanding the properties of nanoporous materials, such as Metal-organic Frameworks (MOFs), which are promising materials for gas storage and separation considering their high surface areas.

Natis Shafiq

Natis ShafiqI am a mechanical engineer by training. I joined Dr. Chabal's group on August 2011 after completing my MS in Mechanical and Aerospace Engineering from Oklahoma State University. Currently I am working in a project to design hybrid nanocrystal/Silicon architectures for photovoltaic applications. This research focuses to develop and study advanced hybrid nanostructures for thin film Si based photovoltaic cells based on the concept of non-radiative energy transfer (NRET). My focus lies in developing different 3D substrate geometries to enhance NRET and use graphene oxide/ graphene to develop novel functional hybrid materials to study the energy transfer (NRET/RET) dynamics. In this regard, we extensively use time resolved PL spectroscopy together with FTIR, XPS, SEM, AFM, Raman, UV-Vis-NIR spectroscopy. Previously, I studied the interaction of Graphene oxide intercalated with ionic liquids for ultracapacitor applications using FTIR, XRD and contact angle. Additionally, my research includes the study of reduction mechanism and chemical doping of graphene oxide. Also I am interested in studying the chemical properties of different 2D hybrid structures involving graphene or graphene like other carbon and chalcogenide materials together with different transition metal nanoparticles for enhanced chemical activities. Apart from the projects listed above, I have worked in collaboration with Essilor, a leadning ophthalmic lens manufacturer, to analyze some of their samples using spectroscopic ellipsometry. I enjoy reading books, listening to good music, watching movies and writing. I like to cook and find it rewarding to motivate people towards achieving their goals. I am culturally very enthusiastic and proud to be Bangladeshi by birth.

Amanda Molling

Amanda MollingMy name is Amanda Molling and this my first year as a graduate student in the Materials Science department. My undergraduate degree was in Physics at UTDallas. Recently, I have been working in Dr. Chabal's research group examining colloidal semiconductor nanocrystals and functionalism of silicon substrates. In between classes and lab, I manage the Robotics and Automation Society at UTDallas.



Yingzhen (Catherine) Lu

Yingzhen (Catherine) LuI received my master degree in Chemical Engineering from NC State where I developed a strong interest in energy related materials and atomic layer deposition (ALD) when working with Prof. Gregory Parsons. In 2012, I joined Prof. Yves Chabal's group and continued research in interfacial chemistry. Currently I am studying the interfacial chemistry of CuO/Al nanoenergetic materials, a collaboration between the LSNM and the Laboratory for Analysis and Architecture of Systems (LAAS) in France. This exciting project will allow me to develop an advanced deposition technique (ALD) to chemically control the interfacial layer in nature and structure with atomic precision. Thin films deposited by this method will also be compared with traditional deposition techniques such as magnetron sputtering and pulsed laser deposition (PLD). Moreover, with a home built cluster incorporating FTIR, XPS and LEIS, we will study the Al-oxide interfacial compositions, atomic arrangement, and atomic defects as a function of processing conditions. Aside from academics, I enjoy swimming, hiking, travelling and learning about different cultures.