Zinc tin oxide (ZTO) films deposited by pulsed laser deposition (PLD) are
investigated as a channel layers for transparent thin-film transistors (TTFTs).
Films are deposited on glass for characterization, and transistor channel layers are
deposited onto aluminum oxide-titanium oxide/tin doped indium oxide/glass
substrates (ATO/ITO/glass) to produce TTFTs.
UV-visible spectroscopy on...
Lipids, especially phospholipids, are very common
but important molecules found in cells and animal
tissue, performing many biological functions, particularly
in membranes. Lipids, when mixed with water,
spontaneously form ordered systems, such as micelles,
vesicles and multibilayers. The size of these systems
and their degree of ordering depend on the...
The electrical properties of amorphous and crystalline titanium dioxide polymorphs are reported. Titanium dioxide is a widely used transparent semiconductor and it is a useful oxide model. Using variable temperature transport measurements of thin films, it was possible to establish the activation energy barrier for conduction. This was accomplished using...
The origin of high hole conduction in BaCuQF (Q=S,Se) was investigated by photoemission
measurements and full-potential linearized augmented plane wave band-structure calculations. In
both compounds, the large dispersion near the top of the valence band is realized by admixed states
of Cu 3d and S 3p or Se 4p orbitals,...
Brownian motion is the movement of a particle in a fluid resulting from collisions with surrounding molecules. It has modern applications in simulating fluid dynamics and the motion of proteins in biophysics. Brownian motion simulations generally evolve the initial state by applying Newton’s second law to every particle. These simulations...
We investigate the value of the correlation function of an inhomogeneous hard-sphere fluid at contact. This quantity plays a critical role in statistical associating fluid theory, which is the basis of a number of recently developed classical density functionals. We define two averaged values for the correlation function at contact...
High resolution images of a dim companion in a binary star system can be obtained using a Digital Micromirror Array (DMA) as an optical mask. Imaging can be problematic because the intense light from the main star can saturate the detector and leave the companion unnoticed. Placement of the DMA...
We exhibit long-lived resonances in scattering from two-dimensional soft cage potentials comprised of three and four Gaussian peaks. Specific low-energy resonances with very narrow width are shown to correspond to classical multiple-reflection events. These states have much larger probability densities inside the cage than outside and mimic bound states in...
Suspended metallic carbon nanotubes (m-CNTs) exhibit a remarkably large transport gap that can exceed 100 meV. Both experiment and theory suggest that strong electron-electron interactions play a crucial role in generating this electronic structure. To further understand this strongly-interacting system, we have performed electronic measurements of suspended m-CNTs with known...
Cancer is a hard disease to control because of its ability to spread to different parts of the body. Cancer cells can spread out from a primary tumor to distant organs which gives rise to new cancer cell colonies and more tumors over time. This process is known as metastasis...
Multivariable functions permeate physics, mathematics, and other sciences. Understanding how quantities in multivariable relationships change together – or co-vary – is important for studying physical systems. In this project, we asked junior-level physics majors to describe the covariation of quantities in a multivariable context given a 2D graph. We identified...
Uncertainty relations provide constraints on how well the outcomes of incompatible measurements can be predicted, and as well as being fundamental to our understanding of quantum theory, they have practical applications such as for cryptography and witnessing entanglement. Here we shed new light on the entropic form of these relations,...
Intraexciton transitions in semiconductor quantum wells are modulated by strong and tunable few-cycle terahertz pulses. Time-resolved terahertz-pump and optical-probe measurements demonstrate that the 1s heavy-hole and light-hole exciton resonances undergo large-amplitude spectral modulations when the terahertz radiation is tuned near the 1s–2p intraexciton transition. The strong nonlinear optical transients exhibit...
DNA has a well-defined structural transition-the denaturation of its double-stranded form into two single strands-that strongly affects its thermal transport properties. We show that, according to a widely implemented model for DNA denaturation, one can engineer DNA 'heattronic' devices that have a rapidly increasing thermal conductance over a narrow temperature...
An experiment has been conducted using a triple directional
correlation method developed by K. S. Krane, R. M. Steffen and R.
M. Wheeler (ref. 3). This method is presented and two normal detection geometries are introduced. The performance of the N1- and N2-
geometry was studied in four experiments using...
In 1877 John Kerr described an experiment that demonstrated a quadratic change in refractive index in a plate glass placed in a strong external electric field. This results in a nonlinear relationship between the average electric polarization within the materials and the intensity of the applied electric field. This opened...
Bulk properties of CuSc₁₋ₓMgₓO₂, CuSc₁₋ₓMgₓO₂₊y, BaCu₂S₂, Bai₁₋ₓKCu₂S₂, BaCu₂Se₂
and Bai₁₋ₓKₓCu₂Se₂ are investigated supporting the search for highly conductive p-type
thin films. Mg is an efficient dopant in CuScO₂ with conductivity up to l.5.10⁻² S/cm.
Oxidation of CuScO₂:Mg leads to further increase in conductivity up to 0.5 S/cm. The
amount of...
Herein, a program of research is detailed related to transport through the Si metal oxide semiconductor (MOS) quantum dots fabricated in a process flow compatible with modern ULSI (ultra large scale integrated circuit). Silicon quantum dots were fabricated by placing split gates within a MOSFET structure. Quantum dots of several...
Transparent films of CuScO₂₊ₓ have been prepared which show p-type electrical conductivity. The temperature dependence of the conductivity indicates semiconducting behavior with an apparent room temperature activation energy of 0.11 eV. The highest room temperature conductivity observed was 30 S cm⁻1. Films 110 nm thick show 40% transparency in most...
A knowledge of the time rates for intermediate reactions
during the photolysis of nitrogen dioxide enables one to deduce the
possible intermediate reactions which are responsible. An experiment has been devised and constructed which will measure the time
rates for photochemical reactions occurring in ranges of one micro
second to...
Exciton-polaritons are a form of light-matter coupling that have potential applications as photonic transistors and logic gates. In order for a photonic transistor or logic gate to be integrated with room temperature fiber-optic technology, excitons-polaritons need to be stable at room temperature and compatible with the red and near-infrared wavelengths...
A thermal beam of lithium atoms excited to high Rydberg states
by pulsed electron impact has been studied by time-of-flight analysis.
Near the end of a 35-cm field-free flight path, the excited atoms pass
through a pair of electric field plates before entering an excited-atom
detector. Electric field ionization was...
Liquid surfaces are very abundant in nature. Despite the importance of the liquid
interface in general, experimental molecular-level data was almost completely lacking
prior to the last decade and a half. The intent of this work is to provide a means by
which experimental data on the composition of liquid...
Semiconductors serve an integral role in our technologies today. However, with new advancements in ultra-fast electronics, we are approaching the fundamental speed limits of traditional silicon-based semiconductors. Silicon-based semiconductors typically exhibit photocarrier dynamics in nanosecond timescales. Transition metal dichalcogenides (TMDs) are 2D materials shown to exhibit photocarrier dynamics in picosecond...
Cells in three-dimensional (3D) environments exhibit very different biochemical and biophysical phenotypes compared to the behavior of cells in two-dimensional (2D) environments. As an important biomechanical measurement, 2D traction force microscopy can not be directly extended into 3D cases. In order to quantitatively characterize the contraction field, we have developed...
By alloying face centered cubic CaSe with orthorhombic SnSe, we created the heterostructural alloy
Sn1-xCaxSe. The phase separated lms created with a high deposition temperature acted as highly crys-
talline SnSe while the low deposition temperature lms acted as a mix of SnSe and CaSe. For the alloyed
lms we...
Amorphous multicomponent metals have promising applications in novel electronic devices because of their atomically smooth surface morphology and lack of grain boundaries. It is important to understand the thermal transport properties of amorphous metals and an accurate measurement of their thermal conductivity will be essential for further improvement of device...
This dissertation reports on the computational physics research in the area of
inhomogeneous fluids. I first discuss the theory background for this work beginning
with water, which is important for the two published articles that are presented in
this work (Chapters 5 and 6). Next, I give a brief overview...
The dynamics of the Min-protein system help Escherichia coli regulate the process of cell division by identifying the center of the cell. While this system exhibits robust bipolar oscillations in wild-type cell shapes, recent experiments have shown that when the cells are mechanically deformed into wide, flattened out, irregular shapes,...
A new experimental technique for the study of
atom-surface interactions is obtained by passing an atomic
beam containing high-Rydberg states through a fine mesh
target. The technique is demonstrated to be a sensitive
probe of the electric fields of adsorbed dipole layers in
transmission experiments in which a time-dependent beam...
Effective two-body interactions were obtained from
realistic nucleon-nucleon potentials and applications made
in calculations of ground state properties of even-even N=Z light nuclei. The admixture of high momentum states into
the nuclear wavefunction caused by the strong, short-range
repulsion of the two-nucleon force was taken into account
by making a...
Computational statistical mechanics leans heavily on the class of Markov Chain Monte Carlo Algorithms. Many such algorithms exist, and simulations can run for several weeks, making the selection of algorithms a difficult, but critical task. In this work, we introduce a benchmark system of two quadratic wells with an analytical...
The three-grating optical interferometer is studied to identify restrictions
on alignment and improve stability. A description of the way a three-grating
interferometer works is given as well as a method for proper set up. The overall
power loss through the three gratings is measured and can be used to estimate...
Semiconducting materials which can be ambipolarly doped are highly desirable in many electronics applications, including use as solar cell materials. SnZrS₃ is being investigated for the possibility of ambipolar doping, with potential applications as a solar cell absorber layer. This dissertation covers the synthesis of SnZrS₃ and the related compound...
The N=88 isotones lie on the onset of nuclear deformation and have a complicated nuclear structure. To better understand this region, the nuclear levels of ¹⁵⁰Sm were studied in three different β decay experiments. De-populating γ-rays were measured using the 8π spectrometer, an array of 20 Compton suppressed Ge detectors....
A state selected at random from the Hilbert space of a many-body system is overwhelmingly likely to exhibit highly non-classical correlations. For these typical states, half of the environment must be measured by an observer to determine the state of a given subsystem. The objectivity of classical reality—the fact that...