bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecules in Circuits: A New Type of Microelectronics?
Authors: McCreery Richard Louis , Bergren Adam , Nagy Sayed , Yan Haijun , Bayat Akhtar , Kondratenko Mykola 
Published: February 2020

Molecules may be considered electronic systems, with electrons rapidly moving through orbitals within molecules and also long distances in biological metabolism and photosynthesis. The prospect of incorporating molecules into microelectronic circuits based on silicon and metallic conductors has great potential for enhancing consumer electronics, providing solar energy conversion, and permitting new functions not possible with silicon. In order to combine the electronic properties of molecules with conventional microelectronics, we need to understand how to “connect” to molecules as well as how electrons are transported through molecules. Once the “rules” of charge transport through molecules are understood, it should be possible to “rationally design” new molecular electronic devices for valuable functions not currently possible with silicon. While Molecular Electronics holds great promise, it also presents significant challenges in handling and fabrication of devices with dimensions of only a few nanometers. We use surface chemistry, spectroscopy, and conjugated organic molecules to make “molecular junctions” consisting of a single layer of molecules a few nanometers thick between conducting carbon and copper electrodes, then we study the behavior of molecules as circuit elements. The primary goal is to design and build functional molecular electronic components to greatly enhance the already powerful world of silicon microelectronics.
Recent references:
(1) Yan, H.; Bergren, A. J.; McCreery, R.; Della Rocca, M. L.; Martin, P.; Lafarge, P.; Lacroix, J. C.; Activationless charge transport across 4.5 to 22 nm in molecular electronic junctions; Proceedings of the National Academy of Sciences
2013, 110, 5326.
(2) McCreery, R.; Yan, H.; Bergren, A. J.; A Critical Perspective on Molecular Electronic Junctions: There is Plenty of Room in the Middle; Phys. Chem. Chem. Phys.
2013, 15, 1065.
(3) Sayed, S. Y.; Fereiro, J. A.; Yan, H.; McCreery, R. L.; Bergren, A. J.; Charge transport in molecular electronic junctions: Compression of the molecular tunnel barrier in the strong coupling regime; Proceedings of the National Academy of Sciences
2012, 109, 11498.
(4) Kumar, R.; Pillai, R. G.; Pekas, N.; Wu, Y.; McCreery, R. L.; Spatially Resolved Raman Spectroelectrochemistry of Solid-State Polythiophene/Viologen Memory Devices; Journal of the American Chemical Society
2012, 134, 14869.
Novel Solar Cells Using Carbon Materials
Authors: Shapter Joe George , Tune Daniel , Flavel Ben , Krupke Ralph 
Published: February 2020

Due to the high cost of silicon photovoltaics there is currently great interest in finding alternative semiconductor materials for light harvesting devices. Single walled carbon nanotubes are an allotrope of carbon having unique electrical and optical properties and are promising as future photovoltaic materials. It is thus important to investigate methods of exploiting their properties in photovoltaic devices. Ironically, one way to do this is to combine them with a relatively well understood model semiconductor such as silicon. Nanotube-silicon heterojunction solar cells are a recent photovoltaic architecture with demonstrated power conversion efficiencies of up to 14 % that may in part exploit the photoactivity of carbon nanotubes.
Silicon solar cell devices fabricated with a thin film of the conductive polymer, polyaniline, have been reported but these devices can suffer from poor performance due to the limited lateral current carrying capacity of very thin polymer films. This talk will focus on hybrid solar cell devices of a thin film of polyaniline deposited on silicon and covered by a single walled carbon nanotube film are fabricated and characterised. These hybrid devices combine the conformal coverage given by the polymer and the excellent electrical properties of single walled carbon nanotube films and significantly outperform either of their component counterparts. Treatment of the silicon and carbon nanotubes with hydrofluoric acid and the strong oxidiser, thionyl chloride, leads to a significant improvement in performance.
Hybird Heterojunction and Photoelectrochemistry Solar Cell Based on Silicon and Graphene Woven Fabrics (GWFs)
Authors: Li Xiao 
Published: February 2020

Crystalline silicon based solar cells have drawn tremendous interest in the photovoltaic market. A facile route to obtain GWFs was reported lately by simply replacing copper with copper meshes substrate in chemical vapor deposition. In addition to its extraordinary electromechanical performance, GWFs also has an alternative application as transparent electrodes as well as graphene film in heterojunction solar cell with Si. Although its conductivity may be fade to graphene film, GWFs surely has better light transparency property because of its cross ribbon structures. This structure was also beneficial to embed other materials, such as liquid electrolyte and other conductive polymers for energy harvesting. Recently, solid state electrolyte has attracted a lot of attention due to its great potential in assembling of flexible nanodevices.
In this paper, we proposed a hybrid heterojunction and photoelectrochemistry solar cell based on Si and GWFs. GWFs not only served as the transparent layer for charge collection and transport, but played an important role as p-type layer to form heterojunction with Si. In addition, particular configuration of woven fabrics with empty space between meshes facilitated the filling up of acidic solid state electrolyte. HNO3 solid state electrolyte significantly boosted the efficiency by comprehensively improving the open circuit voltage, short circuit current density and fill factor by simply spin-coating on GWFs-Si solar cell. The role of HNO3 solid state electrolyte was discussed in detail. Different models were designed to confirm the hybrid function existed in the solar cell and we can prove that heterojunction junction and photoelectrochemistry function worked synergistically. By accommodating the density of HNO3 solid state electrolyte, the power conversion efficiency could reach up to 11.03%, which was really encouraging. Subsequent experiment convinced H3PO4solid state electrolyte also had positive effect to enhance power conversion efficiency. By adopting solid state electrolyte, we stood a chance to assemble flexible solar cells by precisely controlling the thickness of Si and maintain the cell efficiency at the same time, which extends the application area of GWFs-Si solar cell to flexible field.
Fig. (a) Optical image of the solar cell (b) schematic diagram of the solar cell
Structure Analysis of C60(CF3)10 Isomers
Authors: Bukovsky Eric V , Larson Bryon , Strauss Steven H. , Boltalina Olga , Popov Alexey A 
Published: February 2020

The molecular structures and solid state packing of molecules are crucial to the performance of organic electronic materials, in devices, in terms of charge mobility in the solid state, charge transfer at interfaces, and electrochemical stability. Few studies have been able to compare such a large number of C60X
n
isomers to ascertain the effects that addition patterns have on physiochemical properties of molecules and domains of molecules. We have now synthesized and characterized 27 isomers of C60(CF3)10, including 11 by single crystal X-ray crystallography, six of these are reported for the first time. This represents the greatest number of fullerene or fullerene derivatives/isomers of any kind that have been structurally characterized. Our primary interest in this particular series of fullerene isomers is their variation in reduction potentials and electron affinities that stem from their respective addition patterns since all isomers have the same number of electron withdrawing CF3 groups. Correlations between molecular structure, packing efficiency (density), and electronic properties will be discussed.
References
1. I. E. Kareev; S. F. Lebedkin; S. M. Miller; O. P. Anderson; S. H. Strauss; O. V. Boltalina, Acta Cryst., E62, o1498 (2006).
2. A. A. Popov; I. E. Kareev; N. B. Shustova; E. B. Stukalin; S. F. Lebedkin; K. Seppelt; S. H. Strauss; O. V. Boltalina; L. Dunsch, J. Am. Chem. Soc., 129, 11551 (2007).
3. I. E. Kareev; S. F. Lebedkin; A. A. Popov; S. M. Miller; O. P. Anderson; S. H. Strauss; O. V. Boltalina, Acta Cryst. E62, o1501, (2006).
4. N. B. Shustova,; D. V. Peryshkov; A. A. Popov; O. V. Boltalina; S. H. Strauss, Acta Cryst. E63, o3129 (2007).
5. I. E. Kareev; A. A. Popov; I. V. Kuvychko; N. B. Shustova; S. F. Lebedkin; V. P. Bubnov; O. P. Anderson; K. Seppelt; S. H. Strauss; O. V. Boltalina, J. Am. Chem. Soc., 130, 13471 (2008).
6. B. W. Larson; E.V. Bukovsky; I. V. Kuvychko; Y. Chen; A. A. Popov; O. V. Boltalina; S. H. Strauss, Manuscript in progress
Synthesis, Characterization and Electrochemical Investigation of Phthalocyanine Compounds Bearing Fluorine Functionality
Authors: Arslanoglu Yasin , Gokceoren Argun T , Hamuryudan Esin 
Published: February 2020

Peripherally substituted symmetrical phthalocyanine derivatives have the potential to use in a wide range of high technology applications, such as in catalysis, in photodynamic therapy, in electrochromic display devices, and as a molecular electronics, or magnetic devices. Phthalocyanines possess an extended π-conjugated electron system which permits π stacking between planar macrocycles. Adding substituents to the periphery of the macrocycles increases their solubility since these substituents increase the distance between the stacked phthalocyanines and enable their solvation. The phthalocyanine complexes are also electrochemically precious complexes due to their excellent electrochemical behaviors. It is well known that the different functionalities changes the features of the MPc complexes, thus electrochemical properties of these complexes should be investigated for possible applications. [1-3]
We present here the syntheses of tetra-substituted fluorine containing biphenyl-malonic ester groups bearing phthalocyanine derivatives with different central metal atoms and investigation of their electrochemical behaviors. All synthesized novel phthalocyanine compounds have been characterized by using their elemental analyses, FT-IR, UV-Vis, 1H NMR, 13C NMR and mass spectroscopic methods. The electrochemical activity of phthalocyanine derivatives were also evaluated from the current–voltage curves obtained by cyclic and differential pulse voltammetric methods.

REFERENCES

1-
A. Koca, Y. Arslanoğlu, E. J Electroanal Chem, 616 (2008), pp. 107–116

2- N.B. Mckeown, B. Dunn, J.W. Goodby, A.R. West (Eds.), Phthalocyanine materials: synthesis, structure and function, Cambridge University Press, Cambridge (1998)

3- H.S. Nalwa, J.S. Shirk, C.C. Leznoff, A.B.P. Lever (Eds.), Phthalocyanines: properties and applications, VCH Publishers Inc, New York (1996), pp. 79–181.
(Invited) Octadecylphosphonic Acid Self-Assembled Monolayers in Low Voltage Electrowetting-on-Dielectric Systems
Authors: Mibus Marcel , Hu Xiaoyu , Knospe Carl , Reed Michael L. , Zangari Giovanni 
Published: February 2020

Electrowetting-on-dielectric (EWOD) is a useful phenomenon in which the apparent contact angle of a conductive liquid upon a dielectric-coated electrode changes in response to an applied electric voltage. Large electrowetting effects can be achieved when the dielectric film has small thickness, large permittivity, and high breakdown field strength [1]. EWOD is the fundamental building block to numerous devices: displays, lens, and electronic paper [2]. The use of self-assembled monolayers (SAMs) has the potential to drastically reduce voltage requirements for contact angle change, when used in conjunction with a high breakdown field strength layer.
We studied self-assembled monolayers on anodic aluminum oxide. The monolayer films are formed using various solvents, immersion times, and formation temperatures. Characterization used contact angles and AFM to assess the quality of the films. Contact angles were studied in both a static and a dynamic configuration to assess the SAMs ability to serve as a hydrophobic layer for EWOD systems.
Static contact angles are measured optically through a Ramé-Hart goniometer system, allowing full electrowetting characterization, such as in Figure 1. The three regions shown are low voltage EWOD, which is modeled according to the Lippman – Young (LY) curve at low voltage: cos(θ) = cos(θ0) + cV2/2γ; where c is capacitance, V is applied voltage, γ is the gas-liquid interface tension, and θ0is the equilibrium angle. This is followed by a saturation region, giving a limiting angle below which an increase in electric field has no effect. Finally, at high field the monolayer desorbs causing a large drop in wetting angle.
Dynamic contact angles describe three phase boundary motion giving “advancing” and “receding” contact angles, with their difference defining the contact angle hysteresis (CAH). The measurements are made using the Wihelmy plate method and a Krüss tensiometer; the technique consists in dipping the plate in the liquid electrolyte, measuring the force as a function of the immersion depth. CAH gives an insight into the homogeneity of the SAM films, since any discontinuity in the SAM may obstruct the drop movement; this is observed in the saturation region of Figure 1. Additionally, the raw force-depth data from the tensiometer system show how the contact angle changes across the sample and through repeated cycles, as shown in Figure 2. The deviation from a linear behavior during immersion and emersion (Figure 2) suggests the presence of inhomogeneities in the SAM; the lines in fact smooth out for SAMs formed at higher immersion time.

References

[1] F. Mugele and J.-C. Baret, “Electrowetting: from basics to applications,” J. Phys. Condens. Matter, vol. 17, no. 28, pp. R705–R774, Jul. 2005.
[2] R. Shamai, D. Andelman, B. Berge, and R. Hayes, “Water, electricity, and between… On electrowetting and its applications,” Soft Matter, vol. 4, no. 1, p. 38, 2008.
The Improvement of FN Degradation in 3-Dimension TR
Authors: Ha Sung Yeob , Park Se Geun , Kim Shin Deuk , Kim Hyun Chul , Lee Kyu Pil , Jung Il Sub 
Published: February 2020

As Transistor length shrink, many unexpected short channel effects occur under 20nm size. Among these short channel effects, this paper explains about reliability problem of FN degradation and its improvement in 3-Dimension Transistor. The graph of Fig.1 demonstrates that there was threshold voltage(Vth) shift after reliability test(High voltage, High temperature, Long time condition). Of course, the original black curve must be maintained its value despite of reliability stress. This phenomenon caused serious reliability problem in the device.
Above all the easiest method to solve this problem was that we increased the thickness of the oxide. However this method had serious demerit that we must endured the current decrease [1]. Therefore the following two methods were considered for solving this problem.
The first method was that we changed the profile of FIN to reduce the leakage current. The electric fields were crowded at the sharp point and degradation could occur well in Fig.2 (a) profile-1. Therefore we made the sharp point be rounded like Fig.2 (b) profile-2 by changing FIN shape. This was good solution to protect charge converging on cusp and to reduce FN degradation. In the graph of Fig.4 we could confirm that profile-2 was better than profile-1. However this method must be applied carefully in device because it generated side effects that were caused by decreased margin of Gate to Active isolation.
The second method was that we reduced fixed charges generation by adjusting the grain size of metal gate. The grain size of metal gate was more lager after all integration than just deposition status. This grain growth acted as (+) charge formation factor in the condition of reliability stress. In other words, at the interface of Si and metal gate the following reaction happened lively (TiN + SiO2 -> TiON + SiO+ ). Therefore we must reduce the grain growth to improve the FN degradation. We knew that the grain size was changed by temperature of TiN deposition through many experiments [2]. In Fig.3 (a), the grain size grew approximately 0.8nm per 30 degrees of TiN deposition temperature. As the TiN deposition temperature increased, gap of grain growth became smaller than low temperature status. It noted that the grain size after all integration is almost same as the grain size of just deposition status like Fig.3 (b) which is real grain TEM image in condition of 660°C.
In conclusion, to confirm enhancement we verified the result of FIN profile optimization and TiN deposition temperature experiment by measuring Vth shift. In Fig.4, Vth shift and residual stress became smaller and smaller as we applied improvement condition.
References
[1] Fundamentals of Modern VLSI Devices, by Yuan Taur and Tak H.Ning
[2] Hsyi-En Cheng, Wen-Jen Lee, C.-M. Hsu, Thin Solid Films Volume 485, Issues 1–2, 1 August 2005, Pages 59–65
(Invited) Challenges in Contact Technologies for Planar/Non-Planar Si Technologies
Authors: Adusumilli Praneet , Alptekin Emre , Breil Nicolas 
Published: February 2020

The transition from 2D planar devices to 3D devices that is underway in the semiconductor industry has significant implications for parasitic resistance & capacitance of CMOS devices. This talk will focus on challenges in contact technologies as we make this transition.
Increases in the width of the channel per foot print and the simultaneous scaling of gate pitch have accelerated the shrink in effective contact area per channel width and has elevated the importance of contact length for formation of low resistance contacts.
Additionally, scaling of gate pitch is leading to new concerns about device yield and defectivity - such as shorts between interconnect contacts due to increase in contact critical dimensions post patterning. This has put renewed focus on anisotropic cleans and other surface preparation techniques. A nominal increase in contact critical dimensions while beneficial for parasitic resistance has a capacitance penalty and this trade off needs to be carefully managed.
Furthermore, an increase in material and process integration complexity adds to the challenge of engineering the specific contact resistivity of the contact metal/source-drain interface. For example, the impact of down stream thermal processing on dopant activation in the source-drain regions needs particular attention.
Finally, the contribution from interconnect metallization to the overall parasitic resistance is on the rise and needs to be mitigated.
Investigation of Na2/3Ni1/3Ti2/3O2 as Novel Bi-Functional Electrode Material for Non-Aqueous, Room Temperature Na-Ion Batteries
Authors: Shanmugam Rengarajan , Lai Wei 
Published: February 2020

Developing long life, low-cost energy storage solutions based on earth abundant minerals is crucial for renewable energy sources, smart electric grid networks, portable electronics and automotive sector. Na-ion batteries, engineered to operate under ambient conditions with non-aqueous electrolytes, offer much promise in that they do not have resource constraints1and by selecting appropriate materials they can be fabricated into high voltage electrochemical cells, similar to Li-ion chemistry.
The objective of the current work is to study the electrochemical properties of a new oxide material with the composition Na2/3Ni1/3Ti2/3O2 (SNTL)2 as a “bi-functional” intercalation-type electrode for Na-ion battery applications. The presence of two transition metals in this layered oxide enables us to activate two redox couples (Ni2+/3+ and Ti4+/3+) of different species in the same material and thereby provides the opportunity to use it as anode or cathode depending on the potential window. This approach of making both electrodes (anode and cathode) using the same material can simplify electrode design and potentially reduce manufacturing costs for commercial applications.
The solid state synthesis conditions of SNTL have been optimized to make phase-pure oxide with minimal particle size as shown in Figure 1a and Figure 1b.
Galvanostatic cycling shows that up to 50% of sodium ions can be removed reversibly by oxidizing nickel from 2+ to higher oxidation state without any significant capacity loss. This contributes to a sloping voltage profile in the range of 3-4.2 V (Figure 1c) with solid solution-type mechanism involving no phase transitions.
Sodium insertion into pristine SNTL, due to its sodium deficient nature, activates the Ti4+/3+ redox couple. This leads to again a sloping voltage profile with an average voltage of 0.7 V vs. Na/Na+ as shown in Figure 1d. The reaction has been confirmed to be of solid solution-type using ex-situ XRD measurements. Thus, SNTL can be used to fabricate 3V intercalation-based Na-ion batteries.
Wet chemistry-based synthetic routes (sol gel) are being currently explored to reduce the particle size, decrease the diffusion length scale of electrons and thereby improve the electrochemical performance under higher currents. Fabrication and testing of solid state batteries using SNTL material as active electrodes (anode and cathode) and Na3Zr2P1Si2O12 material (NASICON)3as fast sodium conducting solid electrolyte is also currently under progress.
References
1. M.D.Slater, D. Kim, E. Lee, C.S. Johnson, Sodium-Ion Batteries, Advanced Functional Materials, 2013, 8, 947-958
2. Y.J. Shin, M.Y. Yi, Preparation and structural properties of layer-type oxides NaxNix/2Ti1-x/2O2, Solid State Ionics, 2000, 132, 131-141
3. Goodenough JB, Hong HYP, Kafalas JA., Fast Na+-Ion transport in skeleton structures. Mater Res Bull 1976, 11(2), 203-220
Organic Redox Active Molecular Engineer for NRF
Authors: Zhang Lu , Huang Jinhua , Vaughey John T , Burrell Anthony K. 
Published: February 2020

Abstract:
Non-aquoes redox flow battery is a unique energy storage technology. Unlike traditional battery systems, the active energy storage material is in mobile phase and could basically be stored anywhere separately. This gives a lot of flexibility in terms of capacity, power and safety control, making it an idea candidate for large scale stationary energy storage application.
Material development for this technology is crucial for possible implementation. Molecular engineer of organic redox active molecules could lead to tunable physical and electrochemical properties, including solubility in organic solvents, molecular mobility, redox potential, and electrochemical reversibility, which are key factors to energy storage applications. Specifically, one family of dimethoxybezene based organic molecules will be discussed in this talk. Dimethoxybezene based molecules have drawn increasing attentions due to their excellent electrochemical activities, especially as redox shuttle additives and possible non-aqueous flow battery catholytes, which both require redox active molecules to be the key functional components. Due to the organic synthesis feasibility, structural improvements could be conducted to intentionally tune the physical or electrochemical properties of dimethoxybezene. For instance, ANL-2 was developed with improved solubility in carbonate based electrolytes and excellent overcharge performance as redox shuttle additive. The success of ANL-2 was based on the previous attempts using various design strategies to improve the solubility of DDB, including asymmetric ANL-1, and DBMOEB (1,4-di-tert-butyl-2,5-bis(2-methoxyethoxy)methoxy-benzene). Other examples are ANL-3 and ANL-4 molecules, with focus on increasing the redox potentials. ANL-3 is able to provide 4.8 V vs Li/Li+ overcharge protection, highest ever reported in the literature. ANL-4, on the other hand, exhibited 4.5 V vs Li/Li+ redox potential and good electrochemical reversibility.