bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Deposition of Mo-Se Thin Films
Authors: Kowalik Remigiusz , Kutyła Dawid , Mech Krzysztof , Zabinski Piotr , Wróbel Mirosław , Tokarski Tomasz 
Published: February 2020

Semiconductors based on selenium are an important class of semiconducting systems which have been widely studied due to their electronic and optical properties. Among them the special attention is focused on molybdenum-selenium system now. The molybdenum chalcogenides are potential electrode materials for photovoltaic and photoelectrochemical applications due to their light absorbing properties in the visible region. Moreover this material has also been used as a catalyst for hydrogen evolution reaction instead of expensive platinum. Usually, thin films of these materials are prepared by high temperature and vacuum techniques. However electrodeposition has been found to be a very good and low-cost method to fabricate thin films of these compounds.
The electrodeposition of thin films of Mo-Se phases from aqueous baths were studied. The effect of different concentrations of selenious acid, sodium molybdate, pH and temperature were examined. Additionally different complexing agents embracing ammonia and citrate were tested. A conventional three-electrode cell: Pt-sheet as counter electrode and Saturated Calomel Electrode (SCE) or Ag/AgCl as reference electrodes were used. The different substrates were used as working electrode: gold, copper and ITO.
Electrodeposition mechanism and kinetics of Mo-Se system deposition were studied by the conventional electrochemical methods. Chronoamperometry and cyclic voltammetry techniques were combined with electrochemical quartz crystal microbalance to analyze this process in details. According to the obtained results the potentiostatic conditions were applied to deposit Mo-Se thin-films. The proper adjustment of the process of electrolysis has a crucial role on the composition and structure of the deposited films, which decide about their properties. The applied potential of electrolysis were changed systematically in ranges within which it significantly effects on the composition and structure of the Mo-Se thin films. The composition and the structure of the deposited thin films were identified by XRF, EDS, XRD and grazing incidence XRD techniques. Moreover the morphology of the samples were analyzed by SEM.
This work was supported by the Polish National Center of Science under grants 2011/01/D/ST5/05743, 2011/01/N/ST5/05509 and AGH University of Science and Technology contract no. 11.11.180.509.
Long Term Degradation of the Crystalline Silicon Solar Cells with Electroplated Cu Grids
Authors: Huang Qiang 
Published: February 2020

One of the main cost in the silicon solar cell manufacturing is the silver paste for the screen-printed front-side grids. Furthermore, the aspect ratio and the conductivity the silver lines have been limited by the screen-printing process and the composite nature of the paste. The low aspect ratio and the low conductivity of the grids dictate a limitation of footprint of the grids and therefore a limitation of cell efficiency. In addition, the process of screen-printing involves high risk of wafer breakage, which further contributes the final cost of solar energy.
Electroplated Cu together with Ni silicide contact layer was proposed decades ago as an alternative for the front-side grid.[1] Light induced electroplating[2-4] was also invented to create minority carriers at the PN junction, allowing the electroplating to take place without reverse biasing the PN diode. While the a lot of efforts have been focused on the development of the manufacturing processes, few studies are available on the long term reliability of the Cu grid.[5]In this paper, the long-term thermal stability of the Cu/Ni metallization on was studied using Si solar cells fabricated with CMOS grade Si substrates.
Solar cells in real operation in the field will be challenged not only by heat, but also by moisture, radiation, and other natural stresses. While the reliability tests for Si solar cells with screen-printed Ag grid have been standardized already, the impacts of these stress elements are unknown to the Cu grids and are typically convoluted. However, the further formation of the silicide that could finally penetrate through the emitter and the diffusion of the Cu across the silicide into the Si are expected to be the major concerns for the Cu grids under thermal stress.
In this study, solar cells were annealed at different elevated temperatures to speed up the degradation. Degradation behaviors of the grids after up to 3 years were studied. Different materials were also evaluated and compared for improvement in the grid reliability. For example, figure 1 shows a comparison between the solar cells plated with pure Ni or NiCo alloy before the silicidation. The presence of Co in the silicide apparently improved the stability of the final grids during the stress tests at elevated temperature. Further detailed discussion will be provided in the talk.

REFERENCES

1 D. A. Yates, US Patent No. 4609565 (1986).

2 L. F. Durkee, US Patent No. 4144139 (1979).

3 L. A. Grenon, US Patent No. 4251327 (1981).

4 G. Hamm and D. L. Jacques, Patent No. 7955977 (2011).

5 J. Bartsch, A. Mondon, K. Bayer, C. Schetter, M. Hörteis, and S. Glunz, Journal of The Electrochemical Society 157(10), H942 (2010).

Fig. 1: IV characterization of Si solar cells after annealing at 300C for different time. The solar cells comprises (upper figure) Ni silicide and (bottom figure) NiCo-alloy silicide as the contact layer.
Electrochemical Synthesis of Composites Based on Polythiophenes and Carbon Materials for Use in Photovoltaic Systems
Authors: Hernández-Moreno Gibran , Gutiérrez-Granados Silvia , Frontana-Uribe Bernardo A. , Maldonado-Rivera José L. 
Published: February 2020

Solar radiation is the renewable energy source with practically unlimited access. Scientific research has development devices capable of transforming this vast resource into electrical energy (solar cells). The organic solar cells (OSC) have emerged as a promising photovoltaic (PV) technology because of he possibility of low cost production and flexible devices. In a normal structured OSC device, the active layer of donor–acceptor blend is sandwiched between the indium tin oxide or ITO (anode) coated on the glass substrate and a low work function metal (cathode). The active layer of OPV is constituted by a mixture of a polymer electron-donating (conjugated polymer) and electron-acceptor compounds (usually fullerene derivatives). This material is blended in a bulk heterojunction architecture in order to enhance the performance device. Currently there are several ways to deposit the active layer (spary coting, thermal evaporation, spin coating), using mainly polymeric chains, aqueous systems and high weight molecules.
The use of electrochemical techniques for the development of conductive polymers, has primarily focused on understanding the mechanisms of polymerization, growth and redox behavior of these. The use of these methods has resulted in the development of polymer films with potential use in transistors, diodes and others.
The aim of this research is the development of photovoltaic devices using electrochemical techniques (cyclic voltammetry and constant potential) to generate the active layer of a conventional device. Performing in situ polymerization, incorporating of electroaceptor material in organic solvents.
The deposits of the active layer is made using a three electrode cell convecional, ITO working electrode, a platinum plate counter electrode, and Ag/AgNO3 reference electrode in acetonitrile, using bithiophene as electron donor molecules, oxidized multi-walled carbon nanotubes, oxidized graphene, ICBA and PCBM as acceptor molecules. Getting different morphologies and behaviors. Morphological analysis of the films were performed using an atomic force microscope (AFM). Determining the morphology and thickness of these layers.
The photovoltaic device was completed using Wood's metal as cathode, thus different devices were obtained.
Finally, the JV curves were obtained of the photovoltaic devices.
Enhancing Fuel Cell Vehicle Lifetime: A Case Study on the Development and Use of a Corrosion-Resistant Electrocatalyst Support
Authors: Ramani Vijay K. 
Published: February 2020

Longevity and reliability are essential for the successful translation of any new electrochemical technology to the marketplace. This paper addresses the issue of fuel cell stack durability in fuel cell vehicles (FCVs), which directly impacts both lifetime and reliability. The crux of the issue is electrolyte and electrocatalyst degradation during FCV operation, the former due to oxidative degradation in the presence of reactive oxygen species, and the latter arising from electrocatalyst and electrocatalyst support corrosion.
In collaboration with Nissan Technical Center North America, we have studied the issue of electrocatalyst support corrosion over the past several years. Carbon has traditionally been the support of choice as it is inexpensive, has high electron conductivity, and has adequate surface area. While carbon is thermodynamically unstable in the operating regime of a fuel cell, its corrosion rate is usually inhibited due to the intrinsically low exchange current density of the carbon electro-oxidation reaction. Unfortunately, during the start-up of a FCV, the fuel cell cathode undergoes potential transients that greatly enhance the overpotential for the carbon corrosion reaction (and greatly enhancing its rate) for short time-periods (milliseconds). Since the FCV will see many such transients during a lifetime of operation, an alternate strategy is required either in terms of inventing a new, corrosion-resistant support, or in terms of an engineering work-around to minimize the impact of the aforementioned potential transients. We have adopted the former approach (developing a new, corrosion-resistant electrocatalyst support material).
This presentation will outline non-proprietary aspects of the challenges encountered in executing this approach, including the need to (and difficulty associated with) truly understand(ing) the mechanism of degradation in an operating FCV, the efforts expended in correlating bench scale tests in the laboratory to post-mortem analyses of field-tested FCVs, the constraints in terms of cost and compatibility of materials, the need to develop truly representative accelerated stress tests that effectively mimic long-term degradation modes in a reasonable timeframe, and the timeline from lab-scale development of a viable alternative material to its implementation.
Keynote: From Science to Product: A Difficult Way
Authors: Rost Marcel J. 
Published: February 2020

Working at the forefront of science, researchers are always interested in having a “toy” that allows unique experiments. In this way they surely can explore new ground and increase the probability for high-impact research and publications. In addition, funding becomes easier, as one has better chances in the competition with the other proposals.
Triggered by the advantage of a video-camera over a photo-camera, everything started 19 years ago with the scientific desire to observe film growth and surface dynamics with significantly higher time resolution. In the meantime we have realized full video-rate STM and we now can observe surface diffusion and phase transitions, live film growth during the deposition, live observation of ion erosion of surfaces, catalytic reactions on an atomic scale in a high-pressure cell at industrial conditions while also monitoring the reaction products, and we have realized a video-rate EC-STM with a bi-potentiostat and a flow cell that allows live observations during e.g. electrodeposition while we can change the potentials and/or (the composition of) the electrolyte. I will present typical examples of the capabilities of the different machines.
Our instruments are also commercially available via Leiden Probe Microcopy, of which I was the main founder in 2005. As I also was the CEO in the first 3.5 years (before I started my research group), I gathered firsthand experience on all crucial aspects that determine the success or the failure of a product that has to be brought from science to business. I will include both the different views of and the interplay between science, the researcher, the institute/university, the company, the market, financial aspects, and IP questions.
We surly have learned surprising lessons, which I will evaluate and, thereby, formulate several 'do's and don'ts of valorization'.
Ironic Chemicals
Authors: West Alan , Banta Scott 
Published: February 2020

Most academic electrochemists and electrochemical engineers have rich and productive careers in research and take great pleasure in teaching. In the increasing statistics-obsessed world of academia, we monitor the impact of our research through publication metrics, while understanding that the interpretation of these measures is not straightforward. Another metric is seeing how our research impacts industrial application. In the high-tech, research intensive, example of copper electrodeposition for ULSI applications, we can observe industrial adaption of ideas for data analysis, paradigms for experimental programs, and through hiring of graduates. Nevertheless, many academic ideas will not be commercialized unless the original inventor or close associate is interested in the pathway from “invention to profit.”
There are multiple pathways that can be taken including direct University licensing of intellectual property and the creation of spin-out companies from the University. From an educational perspective, opportunities exist for students to learn about intellectual property, the unique economics of start-ups, and entrepreneurship. Frameworks to help academics start up companies have emerged, as evidenced, for example, in the NSF I-Corps program.1

We briefly discuss our experience with attempts at licensing intellectual property in the area of laser electroplating. We then discuss ongoing efforts to start up a company, which we have named “Ironic Chemicals.” The company employs a chemolithoautotrophic bacterium, which extracts its energy from the oxidation of ferrous ions to ferric ions. The ferric ions are electrochemically reduced, and the iron electrolyte is re-circulated between the bioreactor and the electrochemical reactor. The organism is genetically modified to produce chemicals or liquid fuels from dilute CO2, eliminating agricultural feedstocks.
We explain the technology behind Ironic Chemicals from both a scientific and business perspective, thereby illustrating how our instincts on speaking to potential investors were wrong. We discuss our experiences in customer discovery, as we attempt to convert an abstract business idea into a concrete understanding of what it will take to succeed. Furthermore, we share our experiences as we navigate questions such as, is the technology mature enough, how do we avoid conflicts of interest, and when should we talk with investors?
1. https://www.nsf.gov/news/special_reports/i-corps/
The First Thin Film Electronic Package: From Invention to Manufacturing
Authors: Krongelb Sol , Romankiw Lubomyr 
Published: February 2020

As late as the end of the 1970’s, electroplating was regarded as a mystical shop art that had no place in microelectronic fabrication. In 1979 IBM introduced a magnetic thin film head made possible by a newly invented process that was based on electroplating – an achievement that cast electroplating in a new light. Today, electroplating has spread into applications ranging from nanoscale patterning of copper BEOL wiring below 10 nanometers on silicon chips to the deposition of materials for synthesis into photovoltaic layers on 60 cm by 120 cm solar panels, and has also made possible the use of metal structures in MEMS devices. The successful production of the thin film head with its precisely patterned high aspect ratio copper coils and its permalloy elements with tightly controlled magnetic properties, which plating experts of the 1970’s deemed impossible to do by plating, made device fabricators receptive to the electrochemical technology they once shunned.
An important new application of electroplating technology was in the fabrication of the multichip module. In advanced computers, these modules were multilayer ceramic structures that provided the power connections to the circuit chips and had a top layer of copper strip lines for data transmission between chips. The strip lines consisted of copper conductors with a rectangular cross-section that might be 6 µm high and 10 to 20 µm wide embedded in polyimide between two ground planes. These structures, which were essentially low-loss transmission lines, had to have precisely controlled propagation characteristics to minimize pulse distortion. Plating through a lithographic mask was an effective way of insuring the tight control on the geometry of the lines necessary to meet this requirement. One aspect of this talk will be to highlight the technical aspects of integrating electrochemical technology into the fabrication process for the transmission lines. The other will address how the scientists and engineers from the IBM T.J. Watson Research Center who had created the thin film head, worked with the development and manufacturing engineers at IBM’s East Fishkill plant to bring electrochemistry into their production line.
References:
S. Krongelb, J.O. Dukovic, M.L. Komsa, S. Mehdizadeh, L.T. Romankiw, P.C. Andricacos, A.T. Pfieffer, K. Wong, The Application of Electrodeposition to Advanced Package Fabrication, SPIE Vol. 1389, International Conference on Advances in Interconnection and Packaging, pp. 249-256 (1990).
S. Krongelb, L.T. Romankiw, J.A. Tornello, Electrochemical Process for Advanced Package Fabrication, IBM J. Res. Dev.
42 (5), pp. 575-585 (1998).
S. Krongelb, L.T. Romankiw, E.D. Perfecto, K.K.H. Wong, Electrochemical Processes in the Fabrication of Multichip Modules, Chapter 11, pp 337-372 in Microelectronic Packaging, edited by M. Datta, T.Osaka, J.W. Schultze, CRC Press, Boca Raton, FL (2005).
Acceleration of Electroless Silver Deposition from Solutions Containing Cobalt(II) as Reducing Agent
Authors: Jagminiene Aldona , Tamasauskaite-Tamasiunaite Loreta , Norkus Eugenijus 
Published: February 2020

By using cobalt(II) complexes with ammonia or organic amines as reducing agents electroless silver plating solutions of high stability were developed; the deposition of high quality Ag layers with plating rate 1 – 3 μm/h are known [1-3].
In this work, the possibilities to increase silver plating rate without changing of concentration of reactants and temperature were studied. The additives enhancing the partial electrochemical reactions of the electroless plating process – anodic Co(II) oxidation and cathodic Ag(I) reduction – were applied. The effect of chloride and bromide ions was studied by electrochemical and chemical kinetics methods, including electrochemical quartz crystal microgravimetry (EQCM).
Electrochemical measurements showed that the Co(II) anodic oxidation on silver electrode is enhanced by the presence of halide ions. At 1 mM level, KCl additive change the rate of Co(II) oxidation only little, while KBr and KI increase the rate considerably. Accelerating effect of halides corresponds to the increase in adsorption ability of halides in the sequence Cl-<Br-<I-, the adsorbed halide ions could facilitate the electron transfer through the halide bridge. The electroless silver deposition was shown to increase by factor of 2-3 at chloride concentrations 20 – 50 mM at satisfactory solution stability. The enhancing effect is related to anodic cobalt(II) oxidation reaction. AFM images of the silver surface showed absence of considerable changes of real surface area, and the rate increase is obviously not caused by development of catalytic surface.
References

1. A. Vaškelis, E. Norkus, Electrochim. Acta 44 (1999) 3667.

A.Vaškelis, J. Jaciauskiene, A. Jagminiene, E. Norkus, Solid State Sci. 4 (2002) 1299.

E. Norkus, A. Vaškelis, A. Jagminiene, L. Tamašauskaite-Tamašiûnaite, J. Appl. Electrochem. 31 (2001) 1061.
Via Superfill with Time Pulse Plating in a Dual Couple Redox System
Authors: Nad Suddhasattwa , Sun Yang , Chalupa Radek , Pendyala Chandrashekhar , Ganesan Kousik 
Published: February 2020

As fine line spacing (FLS) and blind micro vias (BMV) in substrate manufacturing progressively trend towards lower pitch, finer lines and high aspect ratios, electrodeposition of copper has become more challenging in the microelectronic packaging industry. Plating processes in substrate manufacturing necessitate high current densities to meet throughput concerns resulting in a high copper depletion gradient at the surface and via fill challenges to eliminate trapped voids. We present a manufacturable solution demonstrating a defect free, single bath electrolytic plating process by utilizing an “off-time” enabled forward-reverse pulses in a coupled Fe2+/ Fe3+redox plating solution.
DC plating, modulating plating by current density variation, has been the historical norm in plating techniques employed for via fill. Time pulse plating has the added advantage in its ability to tune composition, structure and porosity by employing varied combinations of current amplitudes and time pulses.
In a normal via-fill bottom up plating process, local plating rate is proportional to the local cupric ion concentration. The bottom of the via sees lower concentration than the top of the feature leading to pinch off or void formation. We investigated fluid velocity dependent convective transport inside the via. Flow velocities for both large and small vias were found to be very low for wide range of inlet flow velocities. Peclet numbers of < 10-4indicate an overwhelming dominance of diffusion impacting ion transport in the interior of the feature.
When an “off time” step is incorporated into a pulsed plating recipe, it enables the relaxation of the cupric ion gradient inside the via feature by diffusion (unhindered by consumption along the vertical sidewall) while the presence of the Fe2+/ Fe3+redox couple enables preferential etching of the top of the via feature versus the bottom. This exaggerates the bottom-up fill effect and can be tuned to achieve super fill of the vias leading to a robust void free filling.
We demonstrate that the incorporation of an “off-time” can result in void free fill and achieve super fill conditions in high aspect ratio via features.