bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Linear and Nonlinear Optical Spectra of Two-Dimensional Materials As Quantum Light Sources
Authors: Perebeinos Vasili
Published: July 2022

The advancement of Quantum Networks for Secure Long-Range Communication and Quantum Sensing technologies critically depends on materials development. There are stringent requirements for the quantum material properties, such as on demand quantum state generation, detection, and transduction. In this talk, I will review solid-state two-dimensional materials platforms for generating quantum light, including excitons, trions, and polaritons as well as nonlinear optical materials for spontaneous parametric down conversion. I will emphases the role of many-body interactions in low dimensional materials and theoretical challenges for describing linear and nonlinear optical properties of quantum materials [1-5].

Y. V. Zhumagulov, A. Vagov, N. Y. Senkevich, D. R. Gulevich, and V. Perebeinos, "Three-particle states and brightening of intervalley excitons in a doped MoS2 monolayer," Physical Review B 101, 245433 (2020).

Y. V. Zhumagulov, A. Vagov, D. R. Gulevich, P. E. Faria Junior, and V. Perebeinos, "Trion induced photoluminescence of a doped MoS2 monolayer," The Journal of Chemical Physics 153, 044132 (2020).

Y. V. Zhumagulov, S. Chiavazzo, D. R. Gulevich, V. Perebeinos, I. A. Shelykh, and O. Kyriienko, "Microscopic theory of exciton and trion polaritons in doped monolayers of transition metal dichalcogenides," arXiv:2107.06927 (2021).

Y. Zhumagulov, A. Vagov, D. Gulevich, and V. Perebeinos, "Electrostatic control of the trion fine structure in transition metal dichalcogenide monolayers", arXiv:2104.11800 (2021).

V. D. Neverov, A. E. Lukyanov, Y. V. Zhumagulov, D. R. Gulevich, Andrey V. Krasavin, A. Vagov, and V. Perebeinos, "Nonlinear spectroscopy of excitonic states in transition metal dichalcogenides," arXiv:2109.11633 (2021).
(Invited) High-Yield and Long-Lived Individual Triplet Exciton Generation Using Covalently-Linked Tetracene Dimers through Intramolecular Singlet Fission
Authors: Hasobe Taku , Tkachenko Nikolai , Kobori Yasuhiro
Published: July 2022

Singlet fission (SF) is a multi-exciton generation process in two neighboring organic chromophores (S1 + S0) where two individual triplet excitons (T1 + T1) are generated from one-photon absorption through a correlated triplet pair (TT) (see: the following equation). Therefore, SF is highly promising for construction of next-generation light energy conversion systems.

S1 + S0 → TT → T1 + T1

In addition to the close interaction of two neighboring chromophores, energy-level matching condition between a singlet and two triplet states: [E(S1) ≥ 2E(T1)] are required for efficient SF. Acene derivatives such as pentacene satisfy the above condition. However, the number of high-yield and long-lived triplet excited states through SF using tetracene derivatives is extremely limited because of the acceleration of the reverse reaction: triplet-triplet annihilation.1-2 Namely, the precise structural control of orientation and distance between two nearby tetracene units is required for long-lived individual triplets through SF. In this presentation, we mainly focus on the high-yield and long-lived individual triplet exciton generation through intramolecular SF (ISF) using a series of phenylene-spacer-bridged tetracene dimers.3

References

Nakamura, S.; Sakai, H.; Nagashima, H.; Kobori, Y.; Tkachenko, N. V.; Hasobe, T. ACS Energy Lett.
2019, 4, 26-31.

Saegusa, T.; Sakai, H.; Nagashima, H.; Kobori, Y.; Tkachenko, N. V.; Hasobe, T. J. Chem. Soc.
2019, 141, 14720-14727.

Nakamura, S.; Sakai, H.; Nagashima, H.; Fuki, M.; Onishi, K.; Khan, R.; Kobori, Y.; Tkachenko, N. V.; Hasobe, T. Phys. Chem. C
2021,
125, 18287-18296.
(Invited, Digital Presentation) Epitaxial Organic Molecular Interfaces As Well-Ordered Model Systems for Molecular Semiconductor p-n Junctions for Optoelectronic Applications
Authors: Nakayama Yasuo
Published: July 2022

Donor-acceptor molecular interfaces are nothing but p-n junctions for organic optoelectronic devices such as organic light emitting diodes and organic solar cells where an exciton forms or dissociates. Understanding about dominating factors determining the intermolecular assembly and charge carrier exchange processes are highly anticipated for the establishment of smart design strategies of practically efficient devices. Molecular heterojunctions built on single crystal organic semiconductors provide well-ordered model systems disentangling complex intermolecular contacts in real devices. Moreover, the p-n junctions of highly ordered molecular assembly lead to the enhancement of the mobility of charge carriers and excitons through the inter-molecular delocalization of the electronic states, which potentially opens a new route for efficient optoelectronic applications of molecular semiconductors. In this contribution, crystallographic and electronic structures of well-ordered molecular semiconductor homo- and hetero-epitaxial junctions are overviewed.

One representative system is a “complementary” p-n junction of perfluoropentacene (C22F14) crystalline ad-layers formed on the single crystal pentacene (C22H14) [1]. Grazing-incidence X-ray diffraction (GIXD) analyses revealed hetero-epitaxial growth of perfluoropentacene in a uniform crystallographic orientation with respect to the surface lattice of the single crystal pentacene. The energy-momentum dispersions of inter-molecular electronic bands were successfully demonstrated by angle-resolved photoelectron spectroscopy (ARPES) for the hetero-epitaxial perfluoropentacene as well as for the single crystal pentacene, which strongly suggests realization of the delocalization of electrons and holes across this well-ordered molecular p-n junction.

To further improve the crystallinity of the epitaxial molecular heterojunctions, the authors’ group proposed a new concept of “quasi-homoepitaxial organic semiconductor junctions”, at which a molecular species with nearly identical in-plane lattice constants to those of the substrate molecular single crystal surface is stacked [2]. Actually, quasi-homoepitaxial crystallites of bis(trifluoromethyl)dimethylrubrene was revealed to form highly-ordered interface of much improved mean crystallite size on the single crystal surface of (unsubstituted) rubrene by means of high-resolution GIXD. The electronic structures exhibiting spontaneous electron transfer at this inter-molecular contact and possible opto-electronic applications of this quasi-homoepitaxial junction are also discussed in this presentation.

This contribution is supported by Grant-in Aids for Transformative Research Areas (A) “Dynamic Exciton: Emerging Science and Innovation” (JSPS-KAKENHI Grant Number JP21H05405).

[1] Y. Nakayama, et al., J. Phys. Chem. Lett. 10 (2019) 1312.

[2] K. Takahashi, et al., J. Phys. Chem. Lett. 12 (2021) 11430.
(Invited) Development of High-Performance Tin Perovskite Solar Cells Via a Sequential Two-Step Deposition Approach
Authors: Diau Eric , Kuan Chun-Hsiao
Published: July 2022

The performance of a tin-based perovskite solar cell (PSC) has undergone rapid progress in recent years but most high-performing devices were fabricated according to a traditional one-step method with the key anti-oxidizer or passivator treated as an additive in the perovskite precursor solution. Herein we present a sequential deposition procedure to passivate the surface of a hybrid mixed cationic perovskite with phenylhydrazinium halide (PHX, X = Cl, Br, I and SCN) dissolved in trifluoroethanol (TFE) solvent. TFE plays an important role not only to give PHX sufficient solubility but also to retain the tin-perovskite films intact for an effective surface passivation characterized by SEM, XRD, GIWAX, SIMS, XPS, UPS, c-AMF and TCSPC. A slow surface passivation was observed; the performance of the PHSCN device improved upon increasing the storage period to attain the best efficiency 13.5 % for a current-voltage scan in the forward bias direction. An inverted effect of hysteresis was observed in that the efficiency of the forward scan was greater than of the reverse scan. An ion-migration model due to the effect of PH surface passivation was proposed to account for the observed phenomena. Furthermore, High-performance tin-based PSC have been extensively explored using PEDOT:PSS as a hole-transport material (HTM) layer according to a one-step fabrication method. In the second part of the work we report tin-based PSC using the concept of a self-assembled monolayer (SAM) to modify the ITO surface with deposition in two steps; a traditional one-step method failed to produce a uniform tin perovskite layer on the ITO/SAM surface because of insufficient surface hydrophilicity. Herein we developed a preheating procedure to diminish effectively the amounts of hydroxyl groups and oxygen vacancies on the ITO surface for a uniform SAM to form, which has been characterized with X-ray photoelectron spectra. We found that the ITO substrate preheated at 400 °C gave the best device performance for an efficiency of power conversion attaining 6.5 % with excellent enduring stability in a glove box for ~1900 h without encapsulation. The present work thus provides a new direction for the development of HTM-free lead-free perovskite solar cells for their future up-scale production.
Corroles As Precursors of Porous Organic Polymers (POPs) and Molecularly Imprinted Polymers (MIPs) - Application to the Detection of CO and the Decontamination of Chemical Nerve Agents
Authors: Gros Claude , Brandès Stéphane , Yang Jian , Monot Camille , Sabat Dimitri , Pacquelet Sandrine , Desbois Nicolas , André Laurie , Estour François , Baati Rachid
Published: July 2022

Detection of carbon monoxide (CO) at few ppm levels is a critical point for quality control of domestic and industrial environment. CO is responsible for thousands of intoxications and hundreds of deaths per year in the world. Moreover, CO is a residual gas found in the industrial dihydrogen used for Proton Exchange Membrane fuel cell, and deactivates the fuel cell prematurely. Corroles have been largely used in sensing applications.[1] Cobalt corroles display high binding affinity for carbon monoxide even in the presence of nitrogen and dioxygen.[2] The affinity of the Co(III) metallocorroles for CO is directly correlated with the Lewis acid character of the metal center. The electrochemistry and spectro-electrochemistry properties have been studied. We have shown that structural modifications on the aromatic ring have a direct influence on the reactivity of the metal complex. We have recently obtained very low CO detection level (ppm) using SAW devices functionalized by cobalt corrole deposited as a film on a silica or a gold surface.[3] Our previous work on the synthesis of porous sol-gel materials functionalized by cobalt corroles gave us encouraging results for CO sorption and detection and prompted us to prepare new porous structured materials functionalized by corrole complexes for gas detection applications. Among all the methods of synthesis of porous architectures, organic materials belonging to the POP (Porous Organic Polymer) family are an appealing and original approach in this research field.[4] The synthesis of new POPs functionalized by cobalt corroles (Fig. 1) will be reported. Their selective sorption properties for CO over N2, O2 and CO2 will be also presented.

Preliminary results concerning the design of Molecularly Imprinted Polymers (MIPS) as enzyme mimics for the decontamination of a broad spectrum of pesticides and chemical warfare agents will be also reported.

Authors would like to acknowledge the ANR program (MIPEnz-Decontam, 20-CE39-0016-01), the FEDER and the “Région Bourgogne” for financial support (ISITE CO2DECIN)

REFERENCES: [1] Di Natale, C.; Gros, C. P.; Paolesse, R., Chem. Soc. Rev.
2022, 000;[2] J.-M. Barbe, G. Canard, S. Brandès, F. Jerôme, G. Dubois, R. Guilard, Dalton Trans.
2004, 1208-1214; [3] Vanotti, M.; Poisson, S.; Soumann, V.; Quesneau, V.; Brandes, S.; Desbois, N.; Yang, J.; Andre, L.; Gros, C. P.; Blondeau-Patissier, V., Sensors and Actuators B: Chemical
2021, (332), 129507. [4] S. Brandès, V. Quesneau, O. Fonquernie, N. Desbois, V. Blondeau-Patissier, C. P. Gros, Dalton Trans.
2019, 48, 11651-11662 (Front Cover).

Figure 1
4-Alkynoic Acids in the Synthesis of Biologically Important Porphyrinoids
Authors: Jacobi Peter Alan
Published: July 2022

In this talk an account is given of the author's use of 4-alkynoic acid derivatives in the synthesis of members of the chlorin, bacteriochlorin and corrin classes of macrocyclic tetrapyrroles. In the case of chlorins, we employed a novel "2+2" condensation to prepare both C,D-symmetric and non-symmetric chlorins, made possible by the ready availability of highly substituted semicorrins derived from 4-alkynoic acids. Alkyne acids also played a prominent role in a new 16p-electrocyclization route to bacteriochlorins, and in iterative syntheses of semicorrins and secocorrins related to vitamin B12. Finally, we describe enantioselective syntheses of ring-C and ring-D alkyne acids for a proposed synthesis of cobyric acid.

Figure 1
Functionalized Tetraaryltetrabenzoporphyrins
Authors: Jux Norbert , Ruppel Michael , Gazetas Pascal , Lungerich Dominik
Published: July 2022

We will present our research towards tetraaryltetrabenzoporphyrins. This will include synthetic approaches to unsymmetrical derivatives and interactions with fullerenes.

We report on the synthesis, characterization, and properties of some of these novel systems, including structures formed on surfaces.[1-4]

References

[1] M. Ruppel, D. Lungerich, S. Sturm, R. Lippert, F. Hampel, N. Jux, Chem. Eur. J.
2020, 26, 3287-3296.

[2] M. Ruppel, L.-P. Gazetas, D. Lungerich, F. Hampel, N. Jux, J. Org. Chem.
2020, 85, 7781-7792.

[3] M. Ruppel, L.-P. Gazetas, D. Lungerich, N. Jux, Eur. J. Org. Chem. 2020, 40, 6352-6360.

[4] R. Adhikari, J. Kuliga, M. Ruppel, N. Jux, H. Marbach, H.-P. Steinrueck, J. Phys. Chem. C
2021, 125, 7204-7212.

Figure 1
Electronic and Size Effects, in Electrocatalysis By Minimally Substituted Corrole Metal Complexes
Authors: Gross Zeev
Published: July 2022

The last 20 years have evidenced an enormous increase of activity on introducing first row transition metal complexes of corroles as sustainable catalysts for clean production of energy from renewable resources. While triarylcorroles were used almost exclusively for those purposes, contemporary research exposed the demand for corroles that are much smaller in size. We now report the progress in that direction, which resulted in corrole metal complexes of the size required for strong absorbance onto electrodes used for fuel cells and other energy-relevant redox reactions.1 This aspect is shown to come into play in the most important variables for efficient electrocatalytic hydrogen gas production from water: earlier onset potential, larger yield and longer durability.

References

Yadav, S. Khoury, N. Fridman, V. K. Sharma, A. Kumar, M. Majdoub, A. Kumar, Y. Diskin-Posner, A. Mahammed and Z.Gross, Angew. Chem. Int. Ed.
2021, 60, 12829 –12834.

Yadav, I. Nigel-Etinger, A. Kumar, A. Mizrahi, A. Mahammed, N. Fridman, S. Lipstman,I. Goldberg, and Z. Gross, Iscience
2021, 24, 102924

Kumar, P. Yadav, M. Majdoub, I. Saltsman, N. Fridman, S. Kumar, A. Kumar, Mahammed and Z. Gross, Angew. Chem. Int. Ed.
2021, 60, 25097-25103.

Figure 1
The Effect of Second Phase Particles on the Corrosion Resistance of A286 Alloys
Authors: Ku Wei-Chen , Huang Chao-Yu , Lin Chao-Sung
Published: July 2022

A286 alloy (AISI 660) is an austenitic precipitation hardness stainless steel that is widely used in the gas turbine industry, due to its high-temperature strength and oxidation resistance [1]. A286 alloy contains higher Ni (24.23 wt.%) and lower Cr (14.5 wt.%) than AISI 316 and AISI 304. The main precipitation strengthening phase of this alloy is gamma phase γ' [Ni3(Al, Ti)], and second phase particles, which form during solution treatment and aging, include eta phase η (Ni3Ti) and metal carbides and nitrides (TiC, TiN).

Unlike the relation between precipitates (γ', η) and pitting corrosion [2], the influence of TiC and TiN on the pitting corrosion is rarely studied. To investigate the influence of the various second phase particles on the corrosion behavior of A286 alloys, three samples were employed, including the hot-rolled (HR), HR + solution treatment at 980 °C for 1 h, and HR + solution treatment + aging at 720 °C for 16 h.

The corrosion resistance of the various A286 alloy samples were examined by potentiodynamic tests in 3.5 wt.% NaCl solution. The microstructure was investigated via scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS).

The second phase particles of HR A286 were mainly TiC and a few TiN, which were several micrometers in size and distributed intragranularly in the austenite matrix (Fig. 1a, 1d, and 1e). After the solution treatment, many TiC particles with sizes of a couple of micrometers precipitated along the austenite grain boundaries (Fig. 1b). Further aging resulted in the formation of γ' and η particles (Fig.1c). The potentiodynamic curves (Fig.1f) showed that the HR A286 had the lowest pitting potential (Epit) and smallest passivation range, suggesting the formation of TiC particles did not deteriorate the corrosion resistance. Meanwhile, the γ' and η particles resulted in a slight decrease in the Epit and passivation range.

Reference:

[1] H. De Cicco, M.I. Luppo, L.M. Gribaudo, J. Ovejero-García, Microstructural development and creep behavior in A286 superalloy, Materials Characterization 52 (2004) 85-92.

[2] P. De Tiedra, O. Martín, M. San-Juan, Potentiodynamic study of the influence of gamma prime and eta phases on pitting corrosion of A286 superalloy, Journal of Alloys and Compounds 673 (2016) 231-236.

Figure 1
(Digital Presentation) Anti-Corrosion Investigation of Titanium Electrode for Cu Plating
Authors: Fung Kuan-Zong , Li Zih-Jhun , Tsai Shu-Yi
Published: July 2022

For the plating of Cu in many industrial applications, Ti metal is commonly used as the cathode for the reduction of Cu. Titanium metal is known to exhibit adequate corrosion resistance due to the formation of a thin passivation layer on the surface. Under an acidic and high temperature environment, the passivation layer on the surface of the titanium metal tends to react with acidic solution. In other words, Ti metal tends to be corroded in an acidic environment. The corrosion behavior of commercial pure titanium in acid copper sulfate baths was investigated in this study. Available surface treatments were applied to suppress the corrosion of titanium passive layer. The microstructure of titanium metal after immersion in acid copper sulfate solution was examined by using SEM and FIB. The pitted and corroded Ti was clearly observed using SEM. The corrosion mechanism of the titanium metal in the sulfuric acid solution was discussed. In addition, the electrochemical characteristics of commercial pure titanium metal in sulfuric acid solution were also analyzed using the three-pole potential measurement method.
(Dielectric Science & Technology Thomas Callinan Award) Materials and Processes As Enablers for Moore Moore and Beyond Moore Technologies
Authors: De Gendt Stefan
Published: July 2022

In this presentation, an overview will be presented of historic and recent developments achieved w.r.t. materials and processes that enabled continued performance scaling of CMOS and beyond CMOS applications. Starting from early high-k work. For decades, thermal oxidation of crystalline Silicon into SiO2 has been the gate oxide material in CMOS technology. Miniaturization for performance improvement, required the gate dielectric to decrease in thickness to support the required increase in capacitance (per unit area) and drive current (per device width). Early 2000, the thickness scaled below 1.5 nm, causing drastically increased leakage currents, high power consumption and reduced device reliability. Replacing the SiO2 gate dielectric with a high-κ (dielectric constant) material allows increased gate capacitance without the associated leakage effects. Activities involved the unit process step development of dielectric and metal deposition processes, advanced interface preparation, electrical and physical characterization and wet and dry etch process development. In a second section, emphasis will be on emerging nanomaterials. Nanotechnology is defined as the manipulation of matter with at least one dimension sized from below 100nm, thus all CMOS activities are functional nanotechnology. The latter concentrated initially on Graphene, but extended further towards Transition Metal Dicalchogenide Materials. Emphasis of the work will be on growth, functionalization, dielectric passivation and doping of these materials. Lastly, expanding on the nanomaterial know-how also progress with regard to low-k dielectrics, area selective deposition processes (for bottom-up lithography) and application of nanochemistry research for photoresist material screening, where chemical interactions at the nanoscale, related to the EUV lithography (radiation chemistry) are hampering the pattern scaling.

Throughout the presentation, recognition will be given to people (PhD students) that contributed to this work and the presentation is also in honor of Prof Dolf Landheer and Professor Samares Kar with whom I organized my first ECS symposium.
Studies on Electrical Energy Storage Density in Lead-Free Ferroelectric Ba1-x SrxTiO3 (x = 0.1, 0.3, and 0.7) Capacitors
Authors: Castillo Ivan , Mishra Karuna K. , Katiyar Ram S.
Published: July 2022

Structure, phonon, and energy storage density were studied in Sr2+-substituted lead-free ferroelectric Ba1-x SrxTiO3 (BSTx) (x = 0.1, 0.3, and 0.7) samples, prepared using solid state reaction techniques, utilizing X-ray diffraction, Raman, and ferroelectric polarization measurement techniques. The system is tetragonal for x = 0.1 with large c/a ratio at room temperature. The tetragonal anisotropy decreases with increasing x, and becoming cubic for x > 0.3. All these structural properties change due to change in the c/a ratio upon rising temperature. Temperature dependent phonon spectroscopic results (80-500 K) indicate reduction in tetragonal to cubic phase transition temperature upon increasing x due to reduction in tetragonal anisotropy (c/a). Overdamping of ~90 cm-1 E-soft phonon mode and a dramatic decrease in the intensity of ~160 cm-1 A-mode were observed at around the tetragonal ferroelectric to cubic paraelectric phase. Using UV-Vis optical absorption spectra, the optical band gaps of these compounds were calculated as 1.73, 1.7, and 1.68 eV as a function of increasing the dopant concentration (x). The energy storage densities of these electrically polled BSTx capacitors were estimated using the polarization hysteresis loops. For x = 0.7, a large energy storage density (Ure) of 20 Joule/cm3 with the efficiency of 57 % was estimated at applied electrical field of 88 kV/cm. Close to Tc large dielectric constant and high energy density values of BSTx capacitors indicate its possible application in high energy storage and pulse power devices. These results will be presented in detail at the meeting.
(Digital Presentation) Silver Nanoparticles Coated Membrane Scaffolds and Fabric Materials as a New Generation of Antiviral Surface Protection Against COVID-19
Authors: Youssef Mohamed F. , Kalil Haitham , Samir Omar , Maher Shaimaa , El-falouji Abdullah I. , Gad Emad
Published: July 2022

One of 2019's biggest scientific challenges is the coronavirus disease (COVID-19). The current COVID-19 epidemic is still a point of interest of all researchers from every field in the hope of finding a way to have it under control. COVID-19 vaccine development is a lengthy procedure that requires several clinical studies to prove its efficacy and overcome the virus mutations. Personal Protective Equipment (PPE) as masks and gloves are essential for moving the battle out of one's body. Developing a highly efficient PPE is crucial, not only to reduce the spread of virus, but also to protect people who work at the frontline.

Virus infection is one of the most serious public health problems facing the world today. Between now and then, several antiviral medicines have been tested to determine their effectiveness as prospective COVID-19 treatments. The rise of viral resistance, as well as the adverse effects associated with antiviral medications, are posing further hurdles, resulting in a decrease in their efficiency as antiviral treatments. This opens the possibility for developing an alternative antiviral material that is both safe and effective. When it comes to their potential to destroy a wide range of viruses, silver nanoparticles (Ag-NPs) laden fiber mats have emerged as a novel antiviral platform, according to the findings of the current study. In the past, Ag-NPs have been extensively examined for their antibacterial properties against a wide range of microorganisms. Their ability to combat hepatitis B and HIV has also been demonstrated to be encouraging, as has their ability to inhibit other viruses such as herpes simplex, monkey pox, and respiratory syncytial virus. Here, we tested the potential effect of silver nanoparticles as an alternative antiviral therapeutic based on their unique properties. When compared to imitative antivirals, elemental silver nanoparticles have the ability to attack many virus sites, reducing the likelihood of the virus developing resistance.

Our group has been developing silver nanoparticles loaded on toilet paper seat sheets, cellulose membranes, polymer dressings, and cotton textiles in response to the persistent issue. The new generation of fiber mats will be thoroughly described and tested against SARS-CoV-2 virus. SEM, EDS, TEM, and DLS will be utilized to identify the shape of our fibers and estimate the particle size of the embedded nanoparticles.
(Invited, Digital Presentation) High-κ Gate Oxide Integration and Ohmic Contact Development for AlGaN/GaN MISHEMTs
Authors: Seidel Sarah , Garbe Valentin , Schmid Alexander , Heitmann Johannes
Published: July 2022

GaN based devices are one of the main candidates for current power electronics and RF applications [1,2]. For optimizing device performance, a detailed understanding of the defects contained in the material and the passivation capability of dielectric layers, i.e., the interfacial defect states formed, is mandatory. Here, we will focus on the surface defect passivation and gate leakage current reduction by introducing thin dielectric films as gate insulator in a so-called MISHEMT (metal insulator semiconductor high electron mobility transistors) device using different materials. The impact of a fully amorphous dielectric (Al2O3), which was kept amorphous by the integration of a low thermal budget ohmic contact [3], was compared to an epitaxial dielectric film (GdScO3) [4]. Due to the band alignment and the high dielectric constant of GdScO3, the spillover effect as it was seen for Al2O3 [5] has been suppressed and a reduction of threshold voltage shift due to the additional capacitance by the dielectric layer has been achieved. In addition, AlTiOx films were investigated as gate dielectrics [6]. To avoid further deterioration of the dielectric layer by the ohmic contact formation anneal, a gate last integration scheme was carried out using Ti based gold free ohmic source and drain contacts [7]. By varying the Al content, the band alignment between the underlying GaN capping layer to the thin film dielectric was controlled. By this means and additional charge engineering in the dielectric layer, a gate leakage reduction with limited threshold voltage increase has been realized. All dielectric layers have been electrically characterized in detail. Interface trap densities were measured by photo-assisted capacitance voltage measurements and an in-depth comparison of the dielectric layers and their impact on the device performance will be given.

[1] Yole Developpement, RF GaN Market: Applications, Players, Technology and Substrates 2019, Market & Technology Report, (2019)

[2] T. Kimoto, Jpn. J. Appl. Phys. 54, 40103 (2015).

[3] Schmid, A.; Schröter, Ch.; Otto, R.; Schuster, M.; Klemm, V.; Rafaja, D.; Heitmann, J., Appl. Phys. Lett. 106, 053509 (2015)

[4] Seidel, S., Schmid, A., Miersch, C., Schubert, J., Heitmann, J. Appl. Phys. Lett., 118(5), 052902 (2021)

[5] P. Lagger, P. Steinschifter, M. Reiner, M. Stadtmüller, G. Denifl, A. Naumann, J. Müller, L. Wilde, J. Sundqvist, D. Pogany, C. Ostermaier, Appl. Phys. Lett. 105, 033412 (2014)

[6] N Siebdrath, S. Seidel, A. Schmid, J. Heitmann, Mikro-Nano-Integration; 8th GMM-Workshop, 2020, pp. 1-3.

[7] Garbe, V.; Schmid, A.; Seidel, S.; Abendroth, B; Stöcker, H.; Doering P.; Meyer, D.C.; Heitmann, J., Phys. Stat. Sol. (B), 2100312 (2021)
(Invited) Magneto-Ionic Control of Heterostructures and Interfaces
Authors: Liu Kai
Published: July 2022

Magneto-ionics has shown promise for energy-efficient nanoelectronics, where ionic migration can be used to achieve atomic scale control of interfaces in magnetic nanostructures, and in turn modulate a wide variety of functionalities. Recently, we have discovered that chemisorbed oxygen and hydrogen on the surface of ferromagnetic films can induce significant Dzyaloshinskii–Moriya interaction (DMI) [1], a handle to introduce topology into nanoscale magnets. This has enabled direct tailoring of skyrmions winding number as well as wall type at room temperature via oxygen chemisorption. We have also demonstrated a sensitive and reversible chirality switching of magnetic domain walls [2] and writing/deleting of skyrmions [3] via hydrogen chemisorption/desorption. These chemisorption induced magnetic effects on controlled ferromagnet surfaces offer an ideal platform to gain quantitative understanding of magneto-ionics at buried interfaces, where the ionic motion can be further controlled by an electric field [4]. These effects are relevant for 3-dimensional information storage as a potentially contactless way to address spin textures, such as in interconnected nanowire networks [5]. Interestingly, nanoporous metal foams made of random assemblies of nanowires have found applications in deep-submicron particulate filtration, relevant to combatting COVID-19 and air pollution. Such foams are efficient, breathable, light-weight, robust, and can be reused and recycled [6]. Our mask design based on such foams has been selected by BARDA-NIOSH as a Phase 1 Winner of the Mask Innovation Challenge [7].

[1] Science Advances, 6, eaba4924 (2020).

[2] Physical Review X, 11, 021015 (2021).

[3] DOI: https://doi.org/10.21203/rs.3.rs-575830/v1

[4] ACS Applied Materials and Interfaces, 13, 38916−38922 (2021).

[5] Nano Letters, 21, 716-722 (2021).

[6] Nano Letters, 21, 2968-2974 (2021).

[7] https://drive.hhs.gov/mask_challenge.html.

This work has been supported by the NSF (DMR-1905468, DMR-2005108, ECCS-1933527), the nCORE SMART center through SRC/NIST, the University of California and Georgetown University.
(Invited) Vapor-Phase Infiltration for Microelectronics Applications
Authors: Nam Chang-Yong
Published: July 2022

Vapor-phase infiltration (VPI) is an emerging organic-inorganic materials hybridization technique derived from atomic layer deposition (ALD) wherein gaseous organometallic precursors and co-reactants diffuse into starting organic templates in a sequential and cyclic manner and become hybridized with the organic matrix. The resulting hybrids feature uniquely enhanced materials properties, including but not limited to mechanical, chemical, dielectric, optical, and electrical properties, which are controllable by the type and amount of infiltrated inorganic species. When combined with polymer templates with either dimensional confinement (e.g., lithographically defined polymer patterns) or intrinsic spatial chemical contrast (e.g., self-assembled block copolymer (BCP) thin films), the technique also yields a site-specific infiltration, analogous to area-selective ALD, creating a spatially localized hybridization. Furthermore, the organic matrix of such infiltrated hybrids can be selectively removed by plasma ashing and thermal annealing to generate inorganic nanostructures that inherit the morphology of starting polymer templates, providing an alternative inorganic nanopatterning methodology. In this talk, I will showcase how these features of VPI can be utilized for the applications in microelectronics, including: (a) arbitrary patterning ultrahigh aspect-ratio metal oxide nanostructures; (b) generation of metal-oxide-based nanowire and nanomesh structures for conductometric sensing; and (c) VPI-derived metal-oxide-infiltrated hybrid photoresists for extreme ultraviolet (EUV) lithography.
(Digital Presentation) Evaluation of the O3 and H2o Oxidants in Downscaling Eot of Ferroelectric Hf0.5Zr0.5O2 on Silicon
Authors: Hernandez-Arriaga Heber , Mohan Jaidah , Jung Yong Chan , Kim Jin-Hyun , Rho Chang-Han , Choi Rino , Kim Jiyoung
Published: July 2022

Integrating the HfZrO2 (HZO) on silicon have attracted the attention of researches in the development of ferroelectric field effect transistor (FeFETs) for implementation in high-density memories and neuromorphic devices[1][2]. In this work, it has been investigated the thickness scalability of HZO thin films and the reduction of the equivalent-oxide-thickness (EOT) on Silicon using [(CH3)2N]4Hf and [(CH3)2N]4Zr as precursor and H2O and O3 as oxidants by means of atomic layer deposition. A TiN/HZO/Si structure was fabricated where the Si substrate has been prepared with a HF-last clean to remove the native oxide or SC1-last clean process to form a chemical oxide layer of 1.2nm. The EOT vs thickness analysis shows an interesting alteration in the dielectric constant which is understood as a phase formation in the HZO from the amorphous to the ferroelectric o-phase to be found in the 4 to 5nm region when annealed at 400 °C. Also, the interface thickness between silicon and HZO was reduced when the HZO is scaled down below the transition region and it is confirmed by transmission electron microscopy (TEM). This reduction in the interface is expressed as scavenging effects from the TiN top electrode when the samples are annealed at 400 °C.

[1] J. Y. Kim, M.-J. Choi, and H. W. Jang, “Ferroelectric field effect transistors: Progress and perspective” APL Mater., 9, 021102 (2021)

[2] E. T. Breyer, H. Mulaosmanovic, T. Mikolajick, and S. Slesazeck, “Perspective on ferroelectric, hafnium oxide based transistors for digital beyond von-Neumann computing,” Appl. Phys. Lett, 118, 050501 (2021)
(Invited, Digital Presentation) Exploring New Applications of Luminescent Silicon Nanocrystals
Authors: Pi Xiaodong
Published: July 2022

The luminescence of silicon nanocrystals (Si NCs) has been traditionally studied for various applications such as light-emitting diodes, solar cells and bioimaging[1]. In the past few years we have started exploring the use of Si NCs for emerging optoelectronic synaptic devices[2,3]. As an important type of optoelectronic synaptic devices, electroluminescent synaptic devices have been fabricated by using Si NCs[4,5]. Under the stimulation of electrical spikes these devices give out electroluminescence that decays in the timeframe of tens of microseconds, enabling a series of synaptic functionalities and logic functions. In addition, we have synthesized Er-hyperdoped Si NCs, which emit light simultaneously at the wavelengths of 830 and 1540 nm. It is found that Er-hyperdoped Si NCs are a powerful ratiometric near-infrared fluorescent platform. The rationmetric near-infrared fluorescence may be well used for temperature sensing, which further enables the construction of logic gates[6].

[1] Z. Y. Ni, et al., Materials Science & Engineering R 138, 85-117 (2019).

[2] L. Yin, et al., Nano Letters 20, 5, 3378–3387 (2020).

[3] Y. Wang, et al., Advanced Functional Materials 2107973 (2021).

[4] S. Y. Zhao, et al., Nano Energy 54, 383-389 (2018)

[5] S. Y. Zhao, et al., Science China Materials 62, 1470-1478 (2019)

[6] K. Wang, et al., to be submitted.
(Invited) SiGe/SOI System: Mechanisms of Condensation and Strain Relaxation
Authors: Favre Luc , Bouabdellaoui Mohammed , Assaf Elie , Guelil Imene , Ronda Antoine , Berbezier Isabelle
Published: July 2022

Silicon-Germanium strain engineering has been used for more than two decades in silicon based devices and has contributed to the scaling down of a transistor’s size and to significant improvements in device performance. However, while conventional silicon-germanium based electronics has experienced rapid and steady growth, thanks to this continuous miniaturization of transistors, this trend cannot continue indefinitely. Industry has already moved to alternate methods such as FinFET devices, in which a thin silicon channel is placed vertically, and the FD-SOI (FD-SGOI) design consisting of a thin film Si(SiGe) channel placed horizontally. For nodes scaled down below 28 nm, low power operation will be inherently hindered by both the imperfect interface, non-uniformity of ultra-thin films and quantum confinement effects, which increase the effective bandgap. In these devices, despite the intense research activity on the strained SiGe ultra-thin body, which accounts for a large portion of such microelectronic devices (below the 45 nm node), we still fail to properly understand the mechanisms that limit hole and electron mobilities in SGOI layers. In addition, one of the main challenges for Si based devices remains the fabrication of efficient group-IV photon sources / photon detectors compatible with the microelectronic industry, which would usefully replace the integration of III-V heterostructures on Si. The major bottleneck is that group-IV semiconductor elements have indirect bandgaps, but with possibilities of being transformed to direct bandgaps using strain engineering strategies.

In this presentation, we will review the formation mechanism of Ge-rich layers on SOI by condensation at different temperatures. TEM cross-section and GPA analysis of the heterostructures will be presented. We will also report the physical and optical properties of these heterostructures. Special attention is devoted to the influence of the SiGe thickness reduction (up to few MLs), where quantum confinement is prominent in the optical properties of the layers. Raman and PL results will be presented to better explain such confinement behavior. We show that novel SGOI substrates could represent a key strategy for the fabrication of future photonic devices.
(Invited, Digital Presentation) Photoluminescence in PbS Nanocrystal Thin Films: Manifestation of Energy Transfer
Authors: Tsybeskov Leonid
Published: July 2022

It is widely accepted that photoluminescence (PL) properties of colloidal nanocrystals, specifically PbS, are mainly determined by their composition, size, and shape. In this work, we demonstrated that in densely packed PbS nanocrystal films, low-temperature donor-to-acceptor energy transfer is mainly responsible for the PL spectra narrowing and shift toward longer wavelengths. At elevated temperatures, back energy transfer seems to be responsible for an unusual PL intensity temperature dependence and spectra modifications. A reduction of the PbS nanocrystal density, i.e., an increase of a distance separating the nanocrystals, dramatically reduces the effect, and the PL spectra are entirely governed by the nanocrystal size and size distribution.
(Digital Presentation) Garnet Structure with UVC and UVB Dual-Band Persistent Luminescence
Authors: Wang Xianli , Mao Yuanbing
Published: July 2022

While persistent luminescence (PersL) at visible and infrared are frequently reported in lanthanide-doped inorganic phosphors for night-vision displays and bio-imaging, an awareness to ultraviolet (UV) PersL remains much less. Here, we have designed Pr3+-doped (Ca1.5Y1.5)(Al3.5Si1.5)O12 (CYAS-Pr) through co-substituting Ca2+-Si4+ into a well-known garnet structure, Y3Al5O12. By the strategy of Ca2+-Si4+ co-substitution, the CYAS-Pr exhibits lattice distortion and subsequently an unprecedent UVC and UVB dual-band PersL with maxima at 266 and 311 nm for 12 hours after charged by UV irradiation due to creation of intrinsic trapping centers. The unique PersL performance is contributed by an existence of two different Pr3+ environments at Ca2+ and Y3+ sites of the CYAS host. The CYAS-Pr shows efficient dual information storage and precise long-distance self-sustained “solar-blind” imaging capabilities in a wide and bright field of view. It is expected that the UVC and UVB dual-band PersL CYAS-Pr will find more applications and trigger further exploration towards persistent sterilization and persistent photocatalysis.
Electrodeposition of Cu-Zn and Cu-Mn Films As Precursors for Nanoporous Copper Synthesis
Authors: Castillo Ezer , Dimitrov Nikolay
Published: July 2022

An all-electrochemical approach for the synthesis of fine-structured nanoporous copper (np-Cu) films has been developed which involves the initial electrodeposition of Cu-containing alloys followed by a selective dissolution or dealloying of the less noble metal via anodization. This process leaves a nanoporous, three-dimensional spongy structure. Among these alloys are Cu-Zn and Cu-Mn that are commonly used as protective and decorative coatings. These types of coatings are typically rich in Cu; however, precursor alloys for dealloying purposes must contain high atomic percentages (at%) of the less noble metal. Here, we present the controlled electrodeposition of Cu-Zn and Cu-Mn alloys with Zn and Mn contents of ≥ 60 at% and ≥ 70 at%, respectively, as precursors for np-Cu synthesis.

The co-electrodeposition of Cu-Zn and Cu-Mn alloys were achieved in baths containing pyrophosphate and ammonium sulfate, respectively. These electrolytes serve as a source of ligands that form complexes with Cu (i.e. [Cu(P2O7)]2- and [Cu(NH3)
n
]2+). The use of the complexing agent is necessary to shift the reduction potential of Cu2+ negatively towards that of Zn2+ or Mn2+, thereby decreasing the large deposition potential difference between the two respective metals. The complexation of Cu in either bath was confirmed by voltammetric and spectroscopic studies.

A systematic potentiostatic electrodeposition study revealed that the optimal plating potential for Cu-Zn is at -2.0 V vs. Hg/HgSO4 with an efficiency of 63–73%. At this potential, the alloy composition is tunable by adjusting the respective percent compositions of the Cu2+ and Zn2+ salts in the deposition bath, thereby producing highly crystalline, Zn-rich alloys that are suitable for dealloying purposes (1). For Cu-Mn, galvanostatic deposition at current densities of 100–200 mA⋅cm-2 gave crystalline deposits with low plating efficiencies (<30%) due to the concurrent hydrogen evolution reaction. Nonetheless, Mn-rich alloys were obtained by also varying the concentration ratio of the Cu2+ and Mn2+ salts in the ammine bath (2). The optimization of the Cu-Zn and Cu-Mn alloy plating parameters and conditions including the structural and compositional characterization will be discussed in detail.

References:

Castillo and N. Dimitrov, “Electrodeposition of Zn-Rich CuxZn(1-x) Films with Controlled Composition and Morphology” J. Electrochem. Soc., 2021, 168, 062513.

Castillo and N. Dimitrov, “Electrodeposition of Cu-Mn Films as Precursor Alloys for Nanoporous Cu Synthesis” Electrochem, 2021, 2 (3), 520-533.
Glassy Carbon Electrode Modified with Au Nanoparticles Electrodeposited from Au(III) Dissolved in a Deep Eutectic Solvent and Its Analytical Performance Towards Dopamine Quantification
Authors: Godoy-Colin Estefania , Corona-Avendaño Silvia , Vázquez-Huerta Gerardo , Ramírez-Silva María Teresa , Aldana-González Jorge , Romero-Romo Mario , Palomar-Pardave Manuel Eduardo
Published: July 2022

In this work, the surface of a glassy carbon electrode (GCE) was modified with gold nanoparticles (AuNPs), by potentiostatic electrodeposition, from Au (III) ions dissolved in a deep eutectic solvent formed by choline chloride and urea (reline) at 70 °C. Using electrochemical techniques, both potentiodynamic and potentiostatic, the mechanism and kinetics of the AuNPs nucleation and growth was determined. It was found that the experimental total current density transients jtotal(t) can be adequately describe by a model that Involves adsorption, jad(t), and 3D nucleation and diffusion-controlled growth, j
3D-dc(t),1 see Figure 1a. Furthermore, the modified electrode (GCE/AuNPs) was used in the evaluation of the electrochemical response of dopamine (DA) by means of cyclic voltammetry (CV) and differential pulse voltammetry (PDV) techniques. The results obtained showed that GCE/AuNPs electrode has a greater catalytic activity towards the electrochemical oxidation of DA, with a sensitivity of 129 , see Figure 1b, which is greater than that shown by the bare GCE and comparable to the performance reported for an ITO/AuNPs electrode.2 As well as the presence of a displacement of the oxidation peak towards lower potentials when using the GCE/AuNPs with respect to the bare GCE, which is indicative that GCE/AuNPs requires less energy for the oxidation of DA.

References

[1] C. Ramírez, E.M. Arce, M. Romero-Romo, M. Palomar-Pardavé. The effect of temperature on the kinetics and mechanism of silver electrodeposition. Solid State Ionics. 169 (2004) 81–85.

[2] J. Aldana-González, M. Palomar-Pardavé, S. Corona-Avendaño, M.G. Montes de Oca, M.T. Ramírez-Silva, M. Romero-Romo, Gold nanoparticles modified-ITO electrode for the selective electrochemical quantification of dopamine in the presence of uric and ascorbic acids, Journal of Electroanalytical Chemistry 706 (2013) 69–75

Figure 1
(Invited) Epitaxial Electrodeposition of Wide Bandgap Semiconductors for Transparent and Flexible Electronics
Authors: Switzer Jay , Banik Avishek , Luo Bin
Published: July 2022

Single-crystal silicon is the bedrock of semiconductor devices due to the high crystalline perfection that minimizes electron-hole recombination, and the dense SiOx native oxide that minimizes surface states. One issue with the material is that it is both brittle and opaque. There is interest in moving beyond the planar structure of conventional Si-based chips to produce flexible and transparent electronic devices such as wearable solar cells, sensors, and flexible displays. In this talk we will discuss the electrodeposition of transparent, wide bandgap semiconductors such as ZnO, CuI, and CuSCN that can be produced as epitaxial films on single-crystal and single-crystal-like substrates. These epitaxial films have an orientation that is controlled by the substrate, with electronic properties that mimic those of single crystals. The talk will emphasize the electrodeposition of the wide bandgap hole conductors CuI and CuSCN. They are electrodeposited by electrochemically reducing Cu(II)EDTA to Cu(I) in the presence of either iodide or thiocyanate anions. Cubic CuI deposits as dense films on Si(111), and CuSCN deposits as nanowires on Au(111). The CuI is epitaxial on the Si(111) in spite of a 2.4 nm thick interfacial SiOx layer. The rectifying p-CuI/SiOx/n-Si heterojunction diode shows an ideality factor of 1.5, a built-in voltage of 0.67 V, and a barrier height of 0.91 eV. The crystal structure and morphology of the CuSCN nanowires can be controlled by varying the SCN-/Cu(II) ratio in solution (see Fig. 1). We also show that the epitaxial films can be removed by a simple lift-off procedure to produce single-crystal-like flexible foils of transparent semiconductors.

Fig. 1 – Controlling the crystal structure and morphology of CuSCN nanowires through the SCN-/Cu(II) ratio in solution. Top micrographs are of rhombohedral CuSCN deposited using SCN-/Cu(II) = 4, and the bottom micrographs are of hexagonal CuSCN deposited using SCN-/Cu(II) = 2. The nanowires were both on Au(111), and were deposited at a potential of -0.4 V vs. Ag/AgCl.

Figure 1