bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Quinone-Based Flow Battery for Large-Scale Electrochemical Energy Storage
Authors: Huskinson Brian , Marshak Michael P. , Gerhardt Michael R. , Aziz Michael J. 
Published: February 2020

We report results from an aqueous quinone-bromine redox flow battery in which the negative electrode is a substituted quinone/hydroquinone couple and the positive electrode is bromine/hydrobromic acid. The redox active materials, which can be very inexpensive, contain no metals. Consequently, the cell appears to be a very attractive candidate for inexpensive, large-scale electrical energy storage.
We will report the performance of a small flow battery based on this couple.
Hybrid Organic and Inorganic Redox Active Components for Non-Aqueous Redox Flow Batteries
Authors: Liu Tianbiao , Wang Wei , Wei Xiaoliang , Li Bin , Nie Zimin , Chen Baowei , Sprenkle Vincent 
Published: February 2020

Redox flow battery (RFB), as one of the most promising technologies for large-scale stationary energy storage up to MW (power) or MWh (energy), has attracted increasingly attentions from both academic and industrial research groups.1RFB is characteristic of many attractive advantages including decoupling of energy storage and power output, exceptional design flexibility, excellent scalability and modularity, long service life, high efficiency, etc. These technic merits make
RFB a well-suitable choice to stabilize the power grid and overcome the intermittency of renewable energy sources (solar, wind and hydroelectricity etc.).2 Traditional aqueous RFB (ARFB), although with a number of technic advantages, is primarily limited by low energy density due to the narrow operation voltage confined by water electrolysis and low concentrations of redox components. To circumvent the limitations of the ARFB system, we have initiated research on non-aqueous redox flow battery (NARFB) employing redox active organic3and hybrid organic/inorganic molecules as flowable electrode materials.
In this presentation, we will report our new results on synthetically design and modification of advanced redox active organometallic complexes in order to optimize operating redox potentials and increase concentrations (i.e. volumetric energy density). Electrochemical performance of the new electrode materials for NARFB will be discussed to highlight research and development of NARFB at PNNL and address future research directions.

References:

Z. Yang, J. Zhang, M. C. W. Kintner-Meyer, X. Lu, D. Choi, J. P. Lemmon and J. Liu, Chemical Reviews, 2011, 111, 3577-3613.

W. Wang, Q. Luo, B. Li, X. Wei, L. Li and Z. Yang, Advanced Functional Materials, 2013, 23, 970-986.

W. Wang, W. Xu, L. Cosimbescu, D. Choi, L. Li, Z. Yang, Chemical
Communications, 48, 6669-6671 (2012).

Acknowledgment

We acknowledge financial supportfrom the U.S. Department of Energy’s (DOE’s) Office of Electricity Delivery and Energy Reliability (OE) (under Contract No. 57558). Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.
(Invited) Effect of Annealing on Electronic Carrier Transport Properties of Gamma-Irradiated AlGaN/GaN High Electron Mobility Transistors
Authors: Yadav Anupama , Schwarz Casey , Shatkhin Max , Wang Luther , Flitsiyan Elena , Chernyak Leonid , Liu Lu , Hwang Y.H. , Ren Fan , Pearton Stephen J. , Lubomirsky Igor 
Published: February 2020

AlGaN/GaN High Electron Mobility Transistors (HEMTs) are the most advanced electronic nitride devices to be used at high temperatures and in harshly radiated environments. A clear understanding of radiation effects on these devices is essential in order to predict their behavior in space and terrestrial applications including military, nuclear and high energy physics. Only a limited amount of insight exists into the behavior of III-N based junction transistor after exposure to gamma irradiation. Investigation of gamma-irradiated device properties will provide important information about the defects in semiconductor heterostructures. Therefore, it is important to understand how defects are created by gamma-rays and how they can be healed by annealing. Here we present the impact of gamma-irradiation on AlGaN/GaN heterostructures fundamental properties including carrier transport and recombination. We also report the effect of annealing at 200o C over 25 min on gamma-irradiated samples through monitoring of minority carrier diffusion length using Electron Beam Induced Current (EBIC) method.
We found the relationship between dose, diffusion length and its activation energy after gamma-irradiation and after annealing treatment. Temperature dependent EBIC measurements yielded a decrease in diffusion length with corresponding increase in activation energy after the gamma-irradiation.The increase in activation energy is likely an indication of the creation of deeper gamma irradiation induced defect traps due to nitrogen vacancies. These deep traps reduce the carrier concentration and mobility and increase the activation energy related to carrier recombination. It is evident from our results that annealing of HEMTs that were gamma-irradiated with moderate dose leads to the recovery (depending on dose) of minority carrier diffusion length. The recovery is also reflected in the activation energy returning to its pre-irradiated value. The level of recovery of gamma-irradiated devices after annealing treatment depends on the dose of irradiation. Increase in diffusion length after annealing had been attributed to a reduction in point defects (nitrogen vacancies) induced in AlGaN/GaN by gamma-irradiation.
Luminescent Electrochromic Device Based on a Biohybrid Electrolyte Doped with a Mixture of Potassium Triflate and a Europium β-diketonate Complex
Authors: Fernandes Mariana , Botas A. M. P. , Leones R. , Pereira S , Silva M. M. , Ferreira Rute Sa , Carlos Luis D , Fortunato Elvira , Rego Rosa , de Zea Bermudez V. 
Published: February 2020

The “mixed cation” approach, which basically involves the use of two guest salts instead of a single one, is an attractive procedure that usually results in a significant increase of the ionic conductivity of polymer electrolytes (PEs). Recently, the sol-gel process [1] was successfully combined with the “mixed cation” effect to produce novel luminescent and ion conducting biohybrid electrolytes composed of a di-urethane cross-linked poly(e-caprolactone) (PCL(530)/siloxane hybrid network and a mixture of lithium and europium triflates, with application in electrochromic devices (ECDs) [2].
To enhance the quantum efficiency of these electrolytes, while preserving acceptable levels of ionic conductivity, we have decided in the present work to replace europium triflate by several europium b-diketonate complexes and to include other alkaline metal triflate salts [3,4]. In a previous study we concluded that adding lanthanide aquocomplexes incorporating b-diketonate ligands to d-PCL(530)/siloxane matrix is of interest as it yields an effective protecting cage that efficiently encapsulates the emitting centers and reduces luminescence quenching [5].
The structure, morphology and thermal stability of the new electrolyte systems have been characterized. ECDs have been built with optimized electrolyte samples and their performance has been analyzed by means of UV/VIS and chronoamperometric measurements.
[1] C. J. Brinker, G. W. Scherer, Sol-gel Science: The Physics and Chemistry of Sol-Gel Processing, Academic Press, San Diego, CA, 1990.
[2] M. Fernandes, S. S. Nobre, L. C. Rodrigues, A. Gonçalves, R. Rego, M. C. Oliveira, R. A. S. Ferreira, E. Fortunato, M. M. Silva, L. D. Carlos, V. de Zea Bermudez, ACS Appl. Mater.
Interfaces, 3, 2011, 2953.
[3] S. C. Nunes, V. de Zea Bermudez, M. M. Silva, M. J. Smith, D. Ostrovskii, R. A. S. Ferreira, L. D. Carlos, J. Rocha, A. Gonçalves, E. Fortunato, J. Mater. Chem., 17, 2007,4239.
[4] M. Fernandes, L. C. Rodrigues, R. A. S. Ferreira, A. Gonçalves, E. Fortunato, M. M. Silva, M. J. Smith, L. D. Carlos, V. de Zea Bermudez; Solid State Ionics, 204-205, 2011, 129.
[5] M. Fernandes, V. de Zea Bermudez, R. A. Sá Ferreira, L. D. Carlos, A. Charas, J. Morgado, M. M. Silva, M. J. Smith, Chem.Mater. 19, 2007, 3892.
Electromigration in Passivated Gold Interconnects for GaAs Devices
Authors: Kilgore Steve 
Published: February 2020

Electromigration in metal interconnects is the most pernicious failure mechanism in semiconductor integrated circuits (ICs). Early electromigration investigations were primarily focused on aluminum interconnects for silicon-based ICs. An alternative metallization compatible with gallium arsenide (GaAs) was required in the development of high powered radio frequency (RF) compound semiconductor devices operating at higher current densities and elevated temperatures. Gold-based metallization was implemented on GaAs devices because it uniquely forms a very low resistance ohmic contact and gold interconnects have superior electrical and thermal conductivity properties. Gold (Au) was also believed to have improved resistance to electromigration due to its higher melting temperature, yet electromigration reliability data on passivated Au interconnects is scarce and inadequate in the literature.
Electromigration lifetimes of large quantities of passivated electroplated Au interconnects were measured utilizing high resolution in-situ resistance monitoring equipment. Application of moderate accelerated stress conditions with a current density limited to 2 MA/cm2and oven temperatures in the range of 300°C to 375°C avoided electrical overstress and severe Joule-heated temperature gradients. Temperature coefficients of resistance (TCRs) were measured to determine accurate Joule-heated Au interconnect film temperatures.
A failure criterion of 50% resistance degradation was selected to prevent thermal runaway and catastrophic metal ruptures that are problematic of open circuit failure tests. Test structure design was optimized to reduce resistance variation and facilitate failure analysis. Characterization of the Au microstructure yielded a median grain size of 0.91 µm. All Au lifetime distributions followed log-normal distributions and Black’s model was found to be applicable. An activation energy of 0.80 ± 0.05 eV was measured from constant current electromigration tests at multiple temperatures. A current density exponent of 1.91 was extracted from multiple current densities at a constant temperature. Electromigration-induced void morphology along with these model parameters indicated grain boundary diffusion is dominant and the void nucleation mechanism controlled the failure time.
Reflectance Studies in Silicon Nanowires Grown By Electroless Etching
Authors: Velez Victor H. , Mertens Robert George , Sundaram Kalpathy B 
Published: February 2020

One of the major energy loss mechanisms of solar cells is optical reflection. Utilization of nanostructures in solar cells may eliminate the need for antireflective coating [1]. The antireflective nature of Silicon nanowires (SiNW’s) revealed by their black color and dull appearances have drawn the attention of researchers [2]. Highly oriented SiNWs arrays prepared by electroless etching method can significantly suppress light reflection across a broad spectrum. Reflectivity studies on these show a significantly decrease in optical reflectivity down to 1.3% for 10 µm long SiNWs arrays [3]. Electroless etching is a top-down technique for growing SiNWs and does not need costly and expensive equipment to grow SiNWs as bottom-up methods usually do.
The electroless process begins with the cleaning of silicon substrates. They were cleaned in acetone, methanol and deionized water, then blow-dried with N2. They are dipped in hydrofluoric acid (HF) 49% solution for 1 min to remove any remaining oxide.
The silicon (Si) wafers are dipped for 45 minutes at room temperature in an electroless solution prepared in a petri dish containing silver nitrate (AgNO3) and hydrofluoric acid (HF) [4].
The substrates are dipped and galvanic reactions disperse silver ions on their surface, losing silicon as SiF6. As a consequence of this etching process, the removal of Si via Ag ions results in vertically aligned arrays of SiNWs covered with silver dendrites. Varying the heights of the SiNWs(fig. 1). changes their optical reflectance. A target optical reflection would be 0.8.
Fig 1. Cross sectional SEM images of the vertically standing Si NW arrays obtained by electroless etching.
REFERENCES
[1] Jin-Young Jung, Han-DonUm, Sang-WonJee, Kwang-TaePark, JinHoBang, Jung-HoLee, “Optimal design for antireflective Si nanowire solar cells,” Solar Energy Materials & Solar Cells, 2013.
[2] Baris Ozdemir, Mustafa Kulakci, Rasit Turan and Husnu Emrah Unalan, “Effect of electroless etching parameters on
the growth and reflection properties of
silicon nanowires,” IOP Science, 2011.
[3] Hua Bao and Xiulin Ruan, "Optical absorption enhancement in disordered
vertical silicon nanowire
arrays for photovoltaic applications," OPTICS LETTERS, 2010.
[4] R. G. Mertens and K. B. Sundaram, “Recession and Characterization of Patterned Nanowires Grown by Electroless Etching of Silicon”. ECS Journal of Solid state Science and Technology, 2012.
Synthesis of Cu-in Alloy (CuIn and Cu2In) Nanoparticles in Aqueous Solution for the Application of CIGS Solar Cell
Authors: Takahashi Hideyuki , Fujiki Hironari , Yokoyama Shun , Tohji Kazuyuki 
Published: February 2020

Many researchers have vigorously studied to develop the low cost solar cells with high efficiency. Among the various solar cells, it is well known that CIGS (Cu(In,Ga)Se2) type solar cell shows attractive performances, nevertheless it can be produced lower cost than Si solar cell. These CIGS type solar cell is synthesized by gas phase method. However, since vaporizing temperature of four elements is extremely different, productivity under the gas phase is relatively low, which read the large amount of waste of resources. Thus, to decreasing the cost of CIGS type solar cell, synthesis method with high recovery rate should be developed.
On the other hand, it is also well known that liquid phase reduction methods can be produced the nano materials with high recovery rate. Among the various liquid phase methods, we reported that well crystallized and uniform alloy nanoparticles, such as Pd20Te7, can be synthesized by restrict controlling the homogenization of metallic complexes in the aqueous solution which reading the control of reduction rate, under the room temperature [1]. However, ternary, or more, alloy nano materials with uniform structure can not be synthesized until now, because of difficulty of controlling these conditions.
Therefore, in this study, the relationship between copper and/or indium complex condition in the aqueous phase and its reduction potentials was evaluated.
Amine-based and/or carboxyl-based complexing reagent, were used for the complex reagents. Condition of metallic complexes in the aqueous solution can be restricted to homogenized species by utilizing the theoretical calculation method using the critical stability constants. Detailed calculation procedure was summarized in Ref. 1. Reduction potential of Cu (and/or In) complexes was measured, and synthesized materials were analyzed by XRD.
Calculation was performed for various system, such as the Cu-NO3-OH-glycine system (dissolution of Cu(NO3)2 and glycine). The ratio of each species was Cu : NO3 : malic acid =1 : 2 : 3. Horizontal and vertical axis shows the pH and abundance ratio (%), respectively. As the result, copper complex was successfully restricted to single species, [(Cu2+)(Gly)2], at the pH range over 6. As the same manner, various copper complexes were adjusted at pH10.
By using the reduction potential decided by using CV (cyclic voltammetry), relationship between stability constants of complex reagents and reduction potential were summarized.
It become clear that correlation between reduction potential and stability constants showed the linearly interaction. Moreover, it became apparent that, in order to synthesize CuIn alloy, amine-based complexing reagent which have large stability constants will be needed.
This work was supported by the Grant-in-Aid for Challenging Exploratory Research (No. 25550085).
References: [1]H. Takahashi, et.,al; Applied Catalysis A: General 392, 80-85 (2011)
Plasma Assisted Preparation of PAN-Based Carbon Fiber
Authors: Dong Qi , Cho Hyoung J. , Lu Chunyuan , Park YeongMin , Kim TaeGyu 
Published: February 2020

Carbon fibers’ capabilities could be affected critical on stabilization which were attributed to its manufacturing process. In this study, hydrogen-oxygen gas plasma assisted stabilization (PAS) was utilized for facilitating the oxidation reaction of the PAN-based precursor fibers in variant oxygen gas ratio. While oxygen gas, including in the gas ingredients, consists from 8 sccm, 10 sccm to 12 sccm. A carbonization reaction was carried on under nitrogen gas plasma. All of the involving plasma was generated via plasma-enhanced chemical vapor deposition (PECVD). The effect on preparation of carbon fibers by plasma assist was analyzed using SEM, FT-IR, DSC, and XRD. The tensile strength, modulus and apparent crystallite orientation of carbon fibers were preferential to those conventional preparation precursor fibers. Results of experimental applications of plasma assisted preparation procedure is given to illustrate the carbon fiber manufacturing.
Kerword: carbon fibers, plasma assisted preparation, variant gas ratio, carbon fiber manufacturing
Benzene Adsorption on (110) Surfaces of Transition Metals: Role of Van Der Waals Interaction and Substrate
Authors: Matos Jeronimo , Yildirim Handan , Kara Abdelkader 
Published: February 2020

The characteristics of Benzene adsorption on metals and their alloy surfaces, and the interface features have been the subject of many experimental and theoretical studies. With the availability of the new vdW functionals, we revisit this organic molecule/metal system to assess the influence of vdW interactions on the adsorption as well as to examine the performance of these vdW functionals. We will present the adsorption geometries, adsorption energies and heights, the characteristics of interface electronic structure, and the charge transfer for Benzene adsorption on the (110) surfaces of seven transition metals; Au, Ag, Cu, Pd, Pt, Rh, and Ni. The calculations are carried out using PBE and vdW-DF family functionals implemented in the VASP package. We will provide comparisons with the available experimental and theoretical studies on the adsorption geometries and energies, and the effect introduced by varying surface chemistries. We will also provide comparisons with the recent study for Benzene adsorption on the (111) surfaces of the same metal substrates [1].
[1] H. Yildirim, T. Greber, and A. Kara J. Phys. Chem. C 2013, 117, 20572.
This work is funded by the U.S. Department of Energy Basic Energy Science under Contract No DE-FG02-11ER16243
Surface-Enhanced Raman Scattering Biosenor for Detection of Hepatitis B Virus DNA
Authors: Wu Nick 
Published: February 2020

Surface-enhanced Raman scattering (SERS) has received increasing attention in biological and chemical sensing because of its unique features. At first, the sandwich nanoparticles have been developed as the SERS Probe.1 And then the sandwich nanoparticles are coupled with a gold triangle nano-array chip to create spatially broadened plasmonic “hot spots”, which enables a large density of Raman reporters to experience strong local electromagnetic field enhancement. Such a quasi-periodic structure increases the intensity and area of the localized surface plasmon resonance, which enhances the SERS signal significantly. This nano-architecture has been used to construct a SERS sensor for hepatitis B virus DNA detection. This sensor exhibits the limit of detection as low as 47.6 aM and can discriminate single-base mutant of DNA.

References

[1] M. Li, S. K. Cushing, J. Zhang, J. Lankford, Z. P. Aguilar, D. Ma, N. Q. Wu, Nanotechnology, 23 (2012), 115501.
[2] M. Li, S. K. Cushing, H. Liang, S. Suri, D. Ma, N. Q. Wu, Analytical Chemistry, 85 (2013), 2072-2078.

Acknowledgement:

The resource and facilities used were partially supported by NSF (EPS 1003907), the West Virginia University Research Corporation and the West Virginia EPSCoR Office. The use of WVU Shared Facility was appreciated.
Low-Temperature, High Energy Density Non-Aqueous Redox Flow Battery
Authors: Herr Tatjana , Fischer Peter , Tübke Jens , Pinkwart Karsten , Elsner Peter 
Published: February 2020

Redox flow battery (RFB) is a well-known storage technology. Commercial RFBs are based on aqueous electrolytes, but also several organic electrolytes are evaluated. Organic solvents provide a number of advantages due to their physicochemical properties, such as a wider operating temperature window and a wider stable potential window. Limiting factor in these systems is the solubility of the redox-active species.
In our study the solubility of vanadium(III) acetylacetonate as redoxactive species and tetrabutylammonium hexafluorophosphate as supporting electrolyte were investigated in a ternary solvent mixture containing acetonitrile, 1,3-dioxolane and dimethyl sulfoxide. The solubility could be almost doubled compared to the well-known acetonitrile system [1]. Furthermore the non-aqueous redox flow battery demonstrated good performance at -25°C (Figure 1).
Further studies to improve the solubility of redox-active species and to optimize battery tests are still under research.

Figure 1: Energy efficiency (EE) and coulombic efficiency (CE) of the V(acac)3 RFB in acetonitrile-1,3-dioxolane-dimethyl sulfoxid solvent mixture at -25°C.
Literature:
[1] Shinkle, A. A.; Sleightholme, Alice E. S.; Griffith, L. D.; Thompson, L. T.; Monroe, C. W., Journal of Power Sources 206 (2012) 490–496.