bluuebunny/crossref_metadata_2025_split huggingface dataset:
Light Assisted Electrodeposition for Silicon Solar Cell Copper Metallization
Authors: Huang Qiang 
Published: February 2020

Cu electroplating is of a great deal of interest for the metallization of silicon solar cells due to its comparable resistance with the current silver metallizaion, and its lower cost for both the material and the operation.[1,2] However, the notorious Cu diffusion into Si is of great concern to the devices performance degradation during the life cycle of the cells. Ni silicide and Ni metal layers have been recently reported as part of the integration scheme to enable the Cu metallizaion and greatly improved the solar cell reliability.[3,4] The formation of this Ni silicide and Ni stack structure is to provide a low-resistance contact between the silicon and metal grid, a good adhesion of metal grid, and a diffusion barrier for the Cu. Among them, the Ni silicide formation needs to be well controlled so that it is not too thick to shunt the solar cell.
This paper will present the development of light assisted plating processes for the formation of nickel silicide and copper grids on silicon solar cells, including beaker scale, bench top tool, and pilot tool processing[5,6,7]. The solar cell substrates for plating comprise ~ 60 ohm/sq emitter formed by POCl diffusion, PECVD SiN passivation layer, and evaporated Al back surface field. Electrodeposition of Ni and copper was studied on 4 cm x 4 cm solar cells in small scale studies and 6 in x 6 in cells on tools.
Figure 1 shows the absorption spectra of different electrolytes for deposition and the relation between the applied potential and the light intensity at different constant current densities. Nickel solution has a strong absorption at wavelength between 350 to 450 nm and between 600 to 800 nm. Two regions of operation were clearly observed with a threshold light intensity when a high intensity wide spectrum halogen light source is used for illumination during electroplating. At high illumination, when enough carriers were generated by the light, the plating occurs at the forward bias mode of the diode. As the light intensity decreases below a threshold value, the potential increases significantly and stays at a high value indicating the diode operates at reverse bias mode. The threshold light intensity is dependent on the illumination energy spectrum, solution absorbance, anode shadowing and applied current density. The learnings from beaker scale experiments were directly used to define the tool requirements and process specifications.

REFERENCES

D. A. Yates, US Patent 4,609,565 (1986).

K. Holdermann, US patent 5,543,333 (1996).

J Bartsch, A Mondon, K Bayer, C Schetter, M Horteis, and S W Glunz, J. Electrochem. Soc., 157, H942 (2010).

J Bartsch, A Mondon, C Schetter, M Horteis, S W Glunz, IEEE 35th PVSC, Honolulu HI (2010).

Q Huang, S S Papa Rao, K. Fisher, ECS J. Solid State Sci. Technol., 4, Q75 (2015).

Q Huang, ECS J. Solid State Sci. Technol., 5, P51 (2016).

Q Huang, K B Reuter, Y Zhu, V R Deline, ECS J. Solid State Sci. Technol., 5, Q24 (2016).

Figure 1
(Invited) Electrodeposition of Functional Nanomaterials from Weakly Coordinating Solvents
Authors: Bartlett Philip Nigel 
Published: February 2020

Electrodeposition is already well established as a key process step in the fabrication of electronic devices in microchip manufacture via the double Damascene process (1) and in through template plating in the manufacture of hard disk read write heads (2). Electrodeposition has great potential in the patterned deposition of materials for a range of other applications, such as solid state memory, thermoelectrics or infrared detection. In addition to providing a relatively green and scalable method for the preparation of thin film materials, electrodeposition brings significant advantages in the filling of high aspect ratio nanostructures compared to more conventional preparation processes, such as PVD or CVD, which make it especially appealing for the fabrication of sub 20 nm structures.
The p-block elements and their compounds and alloys are important materials for many electronic applications. Over the last 4 years we have developed an electrolyte system based on compatible tetrabutylammonium chlorometallate metal sources in non-aqueous electrolytes (3, 4) that allows the one-pot preparation of a wide range of functional materials, such as GeSbTe(5), CdHgTe, and BiTe, based on the p-block.
In this lecture I will discuss the electrodeposition of p-block elements from weakly coordinating solvents and present results for the electrodeposition and electrical characterization of GeSbTe solid state memory materials and CdHgTe infrared detector materials and contrast their properties to the properties of conventionally prepared materials.
This work is conducted as part of the ADEPT project funded by EPSRC (EP/N035437/1).

References

1. P. C. Andricacos, C. Uzoh, J. O. Dukovic, J. Horkans and H. Deligianni, IBM J. Res. Dev., 42, 567 (1998).
2. L. T. Romankiw and S. Krongel, “The Path from Invention to Product for the Magnetic Thin Film Head” in Electrochemical Engineering Across Scales: From Molecules to Processes, R. C. Alkire, P. N. Bartlett and J. Lipkowski (Eds), Wiley, Weinheim, 2015.
3. P. N. Bartlett, D. Cook, C. H. de Groot, A. L. Hector, R. M. Huang, A. Jolleys, G. P. Kissling, W. Levason, S. J. Pearce and G. Reid, RSC Adv., 3, 15645 (2013).
4. P. N. Bartlett, J. Burt, D. A. Cook, C. Y. Cummings, M. W. George, A. L. Hector, M. M. Hasan, J. Ke, W. Levason, D. Pugh, G. Reid, P. W. Richardson, D. C. Smith, J. Spencer, N. Suleiman and W. Zhang, Chem. Eur. J., 22, 302 (2016).
5. P. N. Bartlett, S. L. Benjamin, C. H. de Groot, A. L. Hector, R. M. Huang, A. Jolleys, G. P. Kissling, W. Levason, S. J. Pearce, G. Reid and Y. D. Wang, Mater. Horiz., 2, 420 (2015).
Electrodeposition of Aluminum and Aluminum-Ruthenium Films in Ionic Liquids
Authors: Ispas Adriana , Schlag Leslie , Böttcher Rene , Jacobs Heiko O. , Bund Andreas 
Published: February 2020

Aluminum is one of materials often used in different technical applications due to its light weight and its good corrosion resistance. Its melting temperature is around 660°C, therefore, it can be successfully used for corrosion protection of different materials below this point. Intermetallic phases between Al-Ru are promising candidates for corrosion protection in aggressive media at temperatures above 660°C. Polycrystalline Al-Ru layers present an exceptionally high ductility at room temperature. All these physical, chemical and mechanical properties of Al and Al-Ru films make them interesting for a variety of applications.
One can obtain Al and Al-Ru films by sputtering or by sintering by powder metallurgy and casting, as well as by electrodeposition. Aqueous solutions cannot be used for electrodeposition of Al, therefore, ionic liquids (ILs) were chosen in this study as electrolytes.
The electrolyte used in our work for deposition of Al consisted of 1:2 molar ratio of 1-ethyl-3-methylimidazolium chloride, [EMIm]Cl, and AlCl3. As an alternative, 1-butyl-1-methylpyrrolidinium bis[(trifluoromethyl)sulfonyl]amide, [BMP][TFSA], has also been investigated. RuCl3 and AlCl3 were two of the sources chosen for Al and Ru. Moreover, Ru particles produced by gas phase electrodeposition, were added to an Al electrolyte. The morphology and the composition of the deposited layers were investigated by SEM/EDX. The effect of the IL and of the precursor for Ru on the growth of the layers and on the properties of the deposited films will also be discussed.
All-Inorganic Nanocrystal Thin Films Fabricated By Low-Voltage Electrophoretic Deposition
Authors: Dillon Andrew D , Taheri Mohammad , Mengel Shawn , Dastidar Subham , Baxter Jason , Fafarman Aaron T 
Published: February 2020

The solution processability of colloidal nanocrystals (NCs) offers prospective next-generation solar cells significantly reduced fabrication costs, yet methods for scalable deposition of conductive, well-adhered NC films have yet to be realized. Electrophoretic deposition (EPD), a low-waste, high-throughput technique used commercially in other fields, is proposed for depositing solution-processed absorbing layers for solar cells. Here we share methods for fabricating all-inorganic semiconductor-NC films through low-voltage EPD. Through light scattering, absorbance spectroscopy and electric measurements, the fundamental electrochemical reactions and transport processes that occur during EPD are studied. Special emphasis is applied to elucidate the requirements for low-voltage EPD of semiconductor NCs. Through insights gleaned from this study, choice of NC-ligand-solvent combinations and reactor design, film electronic properties and morphology improvements are realized. Low-voltage EPD is demonstrated using both continuous flow and batch reactors in this study.
(Invited) Problems and Solutions for Lithium Metal Rechargeable Batteries
Authors: Blomgren George E 
Published: February 2020

Lithium metal rechargeable batteries were extensively examined from the 1960s until the discovery and development of the lithium ion battery in 19911. The earlier work was compromised by the lack of development of materials of adequate purity, particularly with regard to water content in positive electrode materials and electrolyte solutions. As this aspect was solved by the increasing availability of battery grade materials, some of the basic limitations of the battery became more evident and work was advanced to cope with these problems. Complete solutions were not found when the advent of lithium ion batteries succeeded in avoiding the most severe problems of lithium metal negative electrodes. The state of the art in 1991 will be briefly summarized and the likely directions of continued progress in lithium metal rechargeable batteries will be discussed. Also, the potential advantages and disadvantages of lithium metal batteries will be given. Finally, the state of present art of lithium metal batteries for both solid and liquid electrolytes will be presented and the likelihood of success of present approaches will be considered.

1For the history of lithium ion batteries see: G. E. Blomgren, The Development and Future of Lithium Ion Batteries,
doi: 10.1149/2.0251701jesJ. Electrochem. Soc.
2017, 164,A5019-A5025
(Invited) Advanced Diagnosis Tools for Probing Interfaces and Surfaces in Electrochemical Systems
Authors: Meng Ying Shirley 
Published: February 2020

Several high voltage cathode materials such as Li-excess layered oxide Li(LixNiCoMn)O2 and spinel LiNi0.5Mn1.5O4 are considered to be promising candidates for high-energy electrode material for Li-ion batteries, particularly for electric vehicle applications. Nevertheless, many of these high voltage cathodes suffer from poor cycle life and capacity degradation, especially at elevated temperatures. In this work new findings on surface and interface stability affecting the electrochemical longevity of the high voltage cathode material are investigated using a combination of in situ and ex situ imaging and spectroscopic tools, including: transmission X-ray microscopy, synchrotron X-ray absorption spectroscopy, and double-aberration-corrected scanning transmission electron microscopy. These tools unveil that cation migration and subsequent surface structural changes at the atomic levels are majorly responsible for the degradation. Combining the DFT + U calculations with our experimental observations, a correlation between these interface structural instability and the capacity degradation can be established. On the other hand, with the development of solid-state electrolytes, the solid/solid electrode/electrolyte interfaces present some major challenges in diagnosis methods. We will discuss some of the new diagnosis method development as well.
Multiscale Chemical Evolution of Si Electrode upon Cycling in Li-Ion Cell Using Advanced Characterization Tools
Authors: Guyomard Dominique , Boniface Maxime , Quazuguel Lucille , Danet Julien , Dupre Nicolas , Lestriez Bernard , De Vito Eric , Bordes Arnaud , Rieutord François , Lyonnard Sandrine , Moreau Philippe , Bayle-Guillemaud Pascale 
Published: February 2020

Continuous solid electrolyte interface (SEI) formation remains the limiting factor of the lifetime of silicon nanoparticles (SiNPs) based negative electrodes. Methods that could provide clear diagnosis of the electrode degradation are of utmost necessity to streamline further developments.
We show that a combination of selected techniques, such as 7Li, 19F MAS NMR, XPS, TOF-SIMS and STEM-EELS, provides an in-depth characterization at different scales of the SEI layer forming on the surface of silicon particles as well as its evolution upon cycling.
We demonstrate that STEM-EELS can be used to quickly map SEI components and quantify LixSi alloys from single experiments with nanoscale resolutions down to 5 nm. Exploiting the low-loss part of the EEL spectrum allowed us to circumvent the degradation phenomena that have so far crippled the application of this technique on such beam-sensitive compounds. Our results provide unprecedented insight into silicon failure mechanisms explored at the nanometer scale in full cell configuration. We observe the morphology of the SEI to be extremely heterogeneous at the particle scale but with clear chemical evolutions with extended cycling coming from both SEI accumulation and a transition from lithium-rich carbonate-like compounds to lithium-poor ones. In addition, we were able to correlate local discrepancies in lithiation to the initial crystallinity of silicon as well as to the local SEI chemistry and morphology. Electrode failure mechanisms at the particle scale were directly observed to be related to SiNP disconnection from both electronic and ionic conduction pathways, creating strong heterogeneous lithiation processes leading to some overlithiated SiNPs. It leads to differential swelling, amplified pulverization and enhanced SEI formation. These findings suggest that capacity retention could be improved through a better control of the nanoscale homogeneity of the electrical wiring and accessibility of porosity in these highly electrolyte-reactive electrodes.
Such results emphasize the importance of achieving multiprobe, multiscale and nanoscale analysis by using various advanced characterization tools.
New Operando Technique to Detect Manganese Dissolution from Lithium Manganese Oxide Electrodes
Authors: Zhao Lihong , Chenard Etienne , Sottos Nancy R. , White Scott R. 
Published: February 2020

Lithium manganese oxide is a promising cathode material for the next generation of lithium ion batteries due to its high capacity, low cost, and low toxicity. However, LMO electrode suffer from rapid capacity loss due to degradation of the active material by manganese dissolution into the electrolyte. Significant scientific effort has recently been devoted to understanding the effect of environmental and operating parameters on Mn2+ dissolution (e.g. storage temperature, electrolyte acidity and overcharge/ overdischarge conditions). Yet, no experimental data exits for Mn2+ dissolution during lithiation and delithiation, due to lack of experimental techniques to monitor the Mn2+ ion concentration in real-time in the electrolyte while the battery is in operation.
Here we report an in-operando experimental technique to detect the concentration of Mn2+ ions in electrolyte using a UV-vis probe molecule (4-(2-pyridylazo) resorcinol, PAR) and activator (1,8-bis(dimethylamino)naphthalene, proton sponge) combination. Chelation between the probe molecule and Mn2+ ion induces a color change in the electrolyte, enabling in-operando characterization of Mn2+ dissolution via spectroscopy. The probe molecule is highly selective, and can selectively differentiate trace amount of Mn2+ ions compared to concentrated Li+ ions in the electrolyte solution.
The electrolyte consisted of 1 mol/L LiPF6 in ethylene carbonate/ dimethyl carbonate (1:1 by volume). Mn2+ ions were introduced into the electrolyte by dissolving different amounts of manganese(II) acetylacetonate (Mn(acac)2). Figure 1a shows the range of color of the electrolyte with respect to the concentration of manganese ions. The electrolyte was analyzed by UV-vis spectroscopy and the absorption peak is shown to shift from 490 nm to 534 nm (Figure 1b). When the Mn2+ ion concentration is stoichiometrically lower than probe concentration, all Mn2+ ions in the solution are assumed to be chelated with the probe molecules. Thus, the absorption peak intensity of chelated molecules at the characteristic wavelength (534 nm) is proportional to concentration (Figure 1c), which follows the Beer-Lamber law. Mn2+ concentration in the electrolyte can thus be determined spectroscopically without interfering with the natural operation of Li-ion batteries.

Figure 1
Studying Break-in Phenomena in Lithium-Ion Batteries through Acoustic and Impedance Measurements
Authors: Hodson Thomas , Knehr Kevin William , Steingart Daniel A 
Published: February 2020

Lithium-Ion Batteries (LiBs) have become ubiquitous in modern technologies, such as in the burgeoning electric vehicle and consumer electronics markets. After manufacturing the LiB, a period of “break-in” occurs wherein the battery experiences rapid changes in properties, such as capacity [1] and stress [2], before leveling off to a stable value. Most research in LiBs analyze the full cycle life of the battery and have little regard for the initial break-in period. However, understanding and controlling break-in conditions could determine future performance of the cell. In this study, we use electrochemical acoustic and impedance spectroscopy measurements to analyze break-in of LiBs. We further analyze how break-in conditions, such as varying the rate of current, affect the overall performance of the battery.
[1] Hong, Jong‐Sung, et al. "Electrochemical‐calorimetric studies of lithium‐ion cells." Journal of the Electrochemical Society 145.5 (1998): 1492 [2] Liu, Xinyi M., and Craig B. Arnold. "Effects of Cycling Ranges on Stress and Capacity Fade in Lithium-Ion Pouch Cells." Journal of The Electrochemical Society 163.13 (2016): A2501-A2507.
(Invited) Aluminum Layer Electrodeposition from Aqueous Solutions
Authors: Watkins John D , Zhou Xu , Nulwala Hunaid B. 
Published: February 2020

The electrodeposition of reactive metals, such as aluminum and magnesium, has proven to be an elusive goal in electrochemistry. These metals represent a class of materials that are generally more environmentally friendly than transition metal complexes but due to their overwhelmingly negative reduction potentials, are generally considered impossible to deposit from aqueous solutions. These metals may, however, be electrodeposited from solutions based on organic solvents or ionic liquids, but these media must be kept rigorously dry. In the presence of even trace amounts of water, the relatively low water splitting potential, combined with the relative abundance of water instead leads to excessive gas evolution.
We will show that, by using an ionic liquid inspired ligation approach to metal deposition we were able to successfully shift the reduction potential of reactive metals much less negative. This shift allows the metal reduction to be competitive with water splitting and allows the deposition of a metal rich oxide layer from aqueous solution. These layers were found, under some circumstances to be both adherent and coherent and with thicknesses on the micron scale.

Figure 1
Electrodeposition of Nickel Selenide Thin Films
Authors: Kutyla Dawid , Kolczyk Karolina , Zabinski Piotr , Kowalik Remigiusz 
Published: February 2020

Chalcogenides of transition metals such as zinc, cadmium, cobalt or nickel feature semiconducting properties making them attractive materials for applications in electronics, optics and catalysis. One of the less investigated systems is Ni-Se, although it seems to be very promising material for many purposes. Nickel with selenium can form several selenides of different stoichiometry. NiSe2 can be used as anodic material in modern batteries of high capacity. Moreover NiSe can be successfully applied as a counter-electrode in high energy solar cells. Recently, several works have been devoted to obtain electrocatalytic materials containing nickel with selenium at the same time still featuring comparable properties to noble metal based catalysts.
The article presents results concerning electrochemical deposition of Ni3Se2 from aqueous acidic solutions. The mechanism of electrode reactions in the Ni2+ - H2SeO3 – H2O system was defined with the use of cyclic voltammetry with a gold disk electrode. According to the voltammetry and hydrodynamic methods the process of nickel and selenium co-deposition is determined by the velocity of selenium ions diffusion to the electrode surface. The Ni3Se2 coatings were obtained by the potentiostatic method on copper medium. The elemental composition was determined with the XRF method. The XRD analysis indicated that within potentials from -0.6 to -1.0 V the dominating phase is Ni3Se2. The influence of applied potential and concentration of electroactive species on the elemental and phase composition and the quality of obtained coatings was determined. The surface morphology was observed with the use of scanning electron microscopy.
Acknowledgment
The authors would like to thank Polish National Science Centre for the financial support provided by the grants: No UMO-2016/21/N/ST8/00222, 2011/01/D/ST5/05743, 2016/21/B/ST8/00431 and and the research was carried out in the frames of COST Action MP1407 (e-MINDS).