Ina T. Martin

• Ph.D. Analytical Chemistry
• Managing Director at Case Western Reserve University

The history of art has seen significant shifts in the manner in which artworks are created, making understanding of creative processes a central question in technical art history. In the Renaissance and Early Modern period, paintings were largely produced by master painters directing workshops of apprentices who often contributed to projects. The m...

Remediation of disfiguring scratches and abrasions on aging plastics challenges even the most experienced conservator. This study assesses the effect of three NOVUS polishing products on remediation of poly (methyl methacrylate) (PMMA). Samples were prepared to mimic the depth and type of scratches observed during conservation treatment performed o...

Attribution of paintings is a critical problem in art history. This study extends machine learning analysis to surface topography of painted works. A controlled study of positive attribution was designed with paintings produced by a class of art students. The paintings were scanned using a chromatic confocal optical profilometer to produce surface...

Attribution of paintings is a critical problem in art history. This study extends machine learning analysis to surface topography of painted works. A controlled study of positive attribution was designed with paintings produced by a class of art students. The paintings were scanned using a confocal optical profilometer to produce surface data. The...

Janus particles have anisotropy in surface chemistry or composition that will affect dynamics and interactions with neighboring surfaces. One specific type of Janus particles are those that consist of a native micrometer scale particle with a cap of gold, platinum, or another metal deposited with typical thicknesses of ~10 nm. A key characteristic...

Aluminum-doped zinc oxide (AZO) is a low-temperature processed transparent conductive oxide (TCO) made of earth abundant elements; its applications are currently limited by instability to heat, moisture, and acidic conditions. We demonstrate that the application of an organofunctional silane modifier mitigates AZO degradation, and explore the inter...

Understanding the chemical reaction mechanism and deposition kinetics is of great importance to guide the production of pyrolytic carbon (PC). A practical approach to mimic the commercial chemical vapor deposition (CVD) process and eventually predict the PC deposition rate is highly desired. In this work, a simplified two-step reaction mechanism wa...

Transparent conductive oxides (TCOs) are a known failure mode in a variety of thin film photovoltaic (PV) devices, through mechanisms such as resistivity increase and delamination. Degradation science studies of these materials, as well as most PV systems, have primarily utilized industry standard qualification protocols, which are not designed to...

The lifetime performance and reliability of photovoltaic (PV) modules are critical factors in their successful deployment. Interfaces in thin film PV, such as that between the transparent conductive oxide (TCO) electrode and the absorber layer, are frequently an avenue for degradation; this degradation is promoted by exposure to environmental stres...

Understanding transparent conductive oxide (TCO) degradation is critical to improving stability and lifetime of both organic and inorganic thin lm PV modules, which utilize TCOs, like indium tin oxide (ITO), aluminumdoped zinc oxide (AZO) and uorine-doped tin oxide (FTO) as electrodes. These TCOs must retain their long-term functionality in diverse...

We measure silane density and Sulfo-EMCS crosslinker coupling efficiency on aminosilane films by high-resolution X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) measurements. We then characterize DNA immobilization and hybridization on these films by 32P-radiometry. We find that the silane film structure controls the effici...

Carrier recombination at dislocations is a major source of efficiency loss in epitaxial film Si solar cells and significantly affects the open circuit voltage, V-OC. We develop a simple empirical model that yields a logarithmic relationship between V-OC and the dislocation density, which fits well to our data. Straightforward evaluation of device p...

The amine density of 3-aminopropyldimethylethoxysilane (APDMES) films on silica is controlled to determine its effect on DNA probe density and subsequent DNA hybridization. The amine density is tailored by controlling the surface reaction time of (1) APDMES, or (2) n-propyldimethylchlorosilane (PDMCS, which is not amine terminated) and then reactin...

We grow silicon films by hot-wire/catalytic chemical vapor deposition using a new filament material: TaC-coated graphite rods. The filaments are 1.6mm diameter rigid graphite rods with ~30μm thick TaC coatings. Whereas heated W or Ta wire filaments are reactive and embrittle in silane (SiH4), the TaC/graphite filament is stable. After >2h of exposu...

We have demonstrated that hot-wire chemical vapor deposition (HWCVD) is an excellent technique to produce high-quality epitaxial silicon at high rates, at substrate temperatures from 620 to 800°C. Fast, scalable, inexpensive epitaxy of high-quality crystalline Si (c-Si) in this temperature range is a key element in creating cost-competitive film Si...

Fast epitaxial growth of several microns thick Si at glass-compatible temperatures by the hot-wire CVD technique is investigated, for film Si photovoltaic and other applications. Growth temperature determines the growth phase (epitaxial or disordered) and affects the growth rate, possibly due to the different hydrogen coverage. Stable epitaxy proce...

In this contribution, the authors report on near-field scanning optical microscopy measurements of the luminescence emitted from localized junction breakdown in epitaxial silicon solar cells. Our measurements suggest that the observed local reduction in breakdown voltage results from avalanche multiplication assisted by the reinforcing combination...

We describe recent progress in developing epitaxial film crystal silicon (c-Si) solar cells that can be grown at low temperature (<;760 °C) on seed-on-glass substrates. This low-cost approach is enabled by rapid epitaxy (up to 300 nm/min) of Si films with low dislocation density (<; 1×10⁵ cm^-2) at glass-compatible temperatures...

Nitrogen doping of TiO(2) films (N:TiO(2)) has been shown to improve the visible-light sensitivity of TiO(2), thereby increasing the performance of both photovoltaic and photocatalytic devices. Inductively coupled rf plasmas containing a wide range of nitrogen precursors were used to create nitrogen-doped TiO(2) films. These treatments resulted in...

We construct a phase diagram for silicon layer growth on (001) Si by hot-wire chemical vapor deposition (HWCVD), for rates from 10 to 150 nm/min and for substrate temperatures from 500 to 800 °C. Our results show that a mixed mono and dihydride surface termination during growth causes polycrystalline growth; some H-free sites are needed for epitaxy...

We measure and successfully model the deposition rate (R) of epitaxial Si by hot-wire chemical vapor deposition (HWCVD) onto (100) silicon over a wide range of growth conditions. A deposition rate model based on the fundamentals of gas-filament and gas-substrate interactions is presented; the results are consistent with the observed dependences of...

The performance of 2-μ m -thick crystal silicon (c-Si) solar cells grown epitaxially on heavily doped wafer substrates is quantitatively linked to absorber dislocation density. We find that such thin devices have a high tolerance to bulk impurities compared to wafer-based cells. The minority carrier diffusion length is about half the dislocation sp...

We have applied both sinusoidal and pulse-shaped rf substrate biasing techniques to the expanding thermal plasma deposition of hydrogenated amorphous silicon. Spectroscopic ellipsometry and Fourier transform infrared spectroscopy data demonstrate that both methods of substrate biasing can result in improved film properties at deposition rates rangi...

We report the fabrication of film c-Si solar cells on Si wafer templates by hot wire chemical vapor deposition. These devices, grown at glass-compatible temperatures below 750° C, demonstrate open-circuit voltages greater than 500 mV and efficiencies above 5%. Analysis of the device characteristics and quantum efficiency provides important informat...

Epitaxial crystal silicon films 2 to 10-microns thick on high-quality seed layers have the potential to approach wafer silicon photovoltaic efficiencies at thin-film area costs. Using hot-wire chemical vapor deposition (HWCVD) from silane precursor gas, we have grown epitaxial layers up to 40-microns thick with defect densities of about 2 �? 105 cm...

We demonstrate that epitaxial layers with a wide range of controllable dopant densities (7×1015–3×1018/cm3 and 1017–1018/cm3 for n-type and p-type, respectively) can be grown on wafer substrates at 700±25 °C by hot-wire chemical vapor deposition. Phosphorus from PH3 is incorporated into the film more efficiently than silicon from SiH4, leading to e...

High‐fidelity micrometer‐scale patterns of alternating hydrophobic and hydrophilic materials were created on polystyrene using pulsed plasma polymerization. The hydrophobic material was formed using C 3 F 8 . Grids with 80–100 µm holes were used to generate patterns with acrylic acid, 2‐hydroxyethyl methacrylate, N ‐vinyl‐2‐pyrrolidinone, N ‐vinylf...

Polydimethylsiloxane (PDMS) capillary electrophoresis microchips were modified using plasma‐enhanced chemical vapor deposition (PECVD), resulting in modified electroosmotic flow (EOF) values. Octafluoropropane (C 3 F 8 ) and acrylic acid (AA) plasmas were chosen as initial test systems for device modification. Argon plasma pretreatments were used t...

Cover: A scanning Auger map of the F KLL signal of a capillary electrophoresis (CE) microchip that was treated with a C 3 F 8 inductively‐coupled rf plasma is shown (right). The photograph in the article by I. T. Martin, B. Dressen, M. Boggs, Y. Liu, C. S. Henry, and E. R. Fisher * on page 414.

Relative gas-phase CF2 densities and CF2 surface reactivity were characterized during hot filament chemical vapor deposition (HF-CVD) of fluorocarbon (FC) films using our LIF-based imaging of radicals interacting with surfaces technique. CF2 density shows a clear dependence on the hexafluoropropylene oxide (HFPO) pressure and filament temperature....

Gas-phase and surface analysis techniques were utilized to investigate the effects of gas-phase species on plasma deposited diamond-like carbon (DLC) thin films. A vacuum system was built to perform Langmuir probe and energy analysis-based mass spectrometry measurements to characterize the gas-phase of low pressure, 13.56 MHz inductively coupled pl...

Ion energy distribution (IED) measurements are reported for ions in the plasma molecular beam source of the imaging of radicals interacting with surfaces (IRIS) apparatus. The IEDs and relative intensities of nascent ions in C3F8 and C4F8 plasma molecular beams were measured using a Hiden PSM003 mass spectrometer mounted on the IRIS main chamber. T...

Our imaging of radicals interacting with surfaces (IRIS) method was used to in- vestigate radical-surface reactions during low-temperature plasma-enhanced chemical vapor deposition (PECVD) processes. Special emphasis was placed on the analysis of surface re- activities for CH, SiH, CN, NH, NH2, CF2, and SiCl2 radicals during film growth. The ef- fe...

Thesis (Ph.D.)--Colorado State University, 2005. Includes bibliographical references.

Surface interactions of difluorocarbene (CF2) molecules were investigated using our LIF based imaging of radicals interacting with surfaces (IRIS) apparatus. LIF data of CF2 in C3F8 and C4F8 plasma molecular beams reveal that the relative densities of CF2 increase with increasing rf power and source pressure in both plasma systems. The surface reac...

Materials deposited in continuous wave (cw) and pulsed low-pressure octafluoropropane (C3F8) and octafluorocyclobutane (c-C4F8) plasmas were characterized using Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy, static contact angle measurements, spectroscopic ellipsometry, and scanning electron microscopy (SEM). Fluo...

Ions are known to be key players in many plasma processes, including anisotropic etching, film deposition and surface modification. The relationship between plasma ions, film properties, and surface interactions of other plasma species is not, however, well known. Using our Imaging of Radicals Interacting with Surfaces (IRIS) technique, along with...

We report on fabricating film c-Si solar cells on Si wafer templates by hot-wire chemical vapor deposition. These devices, grown at glass-compatible temperatures < 750..deg..C, demonstrate open-circuit voltages > 500 mV and efficiencies > 5%.