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Keywords: SSNMR, Structure, Dynamics, DNP, Renewable Energy, Perovskites, Batteries, Optoelectronic Materials, Disorder
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Mechanochemical Synthesis of Methylammonium Lead Mixed\textendash Halide Perovskites: Unraveling the Solid-Solution Behavior Using Solid-State NMR Mixed-halide lead perovskite (MHP) materials are rapidly advancing as next-generation high-efficiency perovskite solar cells due to enhanced stability and bandgap tunability. In this work, we demonstrate the ability to readily and stoichiometrically tune the halide composition in methylammonium-based MHPs using a mechanochemical synthesis approach. Using this solvent-free protocol we are able to prepare domain-free MHP solid solutions with randomly distributed halide ions about the Pb center. Up to seven distinct [PbClxBr6–x]4– environments are identified, based on the 207Pb NMR chemical shifts, which are also sensitive to the changes in the unit cell dimensions resulting from the substitution of Br by Cl, obeying Vegard’s law. We demonstrate a straightforward and rapid synthetic approach to forming highly tunable stoichiometric MHP solid solutions while avoiding the traditional solution synthesis method by redirecting the thermodynamically driven compositions. Moreover, we illustrate the importance of complementary characterization methods, obtaining atomic-scale structural information from multinuclear, multifield, and multidimensional solid-state magnetic resonance spectroscopy, as well as from quantum chemical calculations and long-range structural details using powder X-ray diffraction. The solvent-free mechanochemical synthesis approach is also compared to traditional solvent synthesis, revealing identical solid-solution behavior; however, the mechanochemical approach offers superior control over the stoichiometry of the final mixed-halide composition, which is essential for device engineering.T12-P02, T12-P04, T12-Z01 University of Alberta Publication 2018-03-01 Abhoy Karmakar, Abdelrahman M Askar, Guy Bernard, Victor V Terskikh, Michelle Ha, Sahil Patel, Karthik Shankar,
Michaelis, V. T12-P02, T12-P04, T12-Z01 Composition-Tunable Formamidinium Lead Mixed Halide Perovskites via Solvent-Free Mechanochemical Synthesis: Decoding the Pb Environments Using Solid-State NMR Spectroscopy Mixed-halide lead perovskites are becoming of paramount interest in the optoelectronic and photovoltaic research fields, offering band gap tunability, improved efficiency, and enhanced stability compared to their single halide counterparts. Formamidinium-based mixed halide perovskites (FA-MHPs) are critical to obtaining optimum solar cell performance. Here, we report a solvent-free mechanochemical synthesis (MCS) method to prepare FA-MHPs, starting with their parent compounds (FAPbX3; X = Cl, Br, I), achieving compositions not previously accessible through the solvent synthesis (SS) technique. By probing local Pb environments in MCS FA-MHPs using solid-state nuclear magnetic resonance spectroscopy, along with powder X-ray diffraction for long-range crystallinity and reflectance measurements to determine the optical band gap, we show that MCS FA-MHPs form atomic-level solid solutions between Cl/Br and Br/I MHPs. Our results pave the way for advanced methods in atomic-level structural understanding while offering a one-pot synthetic approach to prepare MHPs with superior control of stoichiometry.T12-P02, T12-Z01, T12-Q01 University of Alberta Publication 2018-05-01 Abdelrahman M Askar, Abhoy Karmakar, Guy Bernard, Michelle Ha, Victor V Terskikh, Benjamin Wiltshire, Sahil Patel, Jonathan Fleet, Karthik Shankar,
Michaelis, V. T12-P02, T12-Z01, T12-Q01 Exposing Halide-Mixing in Hybrid Perovskite Materials Using Solid-State NMR Poster PresentationT12-P02, T12-Z01 University of Alberta Activity 2018-07-22 Abhoy Karmakar, Guy Bernard, Michelle Ha, Karthik Shankar,
Michaelis, V. ,
" AM Askar
" ,
" VV Terskikh
" T12-P02, T12-Z01 Mechanistic Investigation on Catalytic Deoxygenation of Phenol as a Model Compound of Biocrude Under Methane T02-Z01 University of Alberta Publication 2018-12-01 Aiguo Wang, Danielle Austin, Peng He, Michelle Ha,
Michaelis, V. , Lijia Liu, Hui Qian, Hongbo Zeng, Hua Song
T02-Z01 Insights into the Structure of Silicon Nanocrystals T06-Z01 University of Alberta Activity 2019-02-12 T06-Z01 Endogenous Dynamic Nuclear Polarization NMR of Hydride-Terminated Silicon Nanoparticles T02-Z01 University of Alberta Publication 2019-04-13 T02-Z01 Understanding the Anatomy of a Silicon Nanocrystal T06-Z01 University of Alberta Activity 2019-05-03 Alyx Thiessen, Michelle Ha, Riley Hooper, Jonathan G C Veinot,
Michaelis, V. T06-Z01 Understanding the Anatomy of a Silicon Nanocrystal T06-Z01 University of Alberta Activity 2019-06-01 Alyx Thiessen, Michelle Ha, Riley Hooper, Jonathan G C Veinot,
Michaelis, V. T06-Z01 MITACS Globalink Research Award T02-Z01 Award 2019-03-01 Michelle Ha
T02-Z01 Postgraduate Scholarship - Doctoral T02-Z01 Award 2019-04-01 Michelle Ha
T02-Z01 Alkaline Earth Metal-Organic Frameworks with Tailorable Ion Release: A Path for Supporting Biomineralization T02-Z01 University of Alberta Publication 2019-08-01 Michelle Ha, M A Matlinska
" ,
" B Hughton
" , Anton Oliynyk,
Iyer, A. , Guy Bernard, G Lambkin
" , M C Lawrence, M J Katz
" ,
Mar, A. ,
Michaelis, V. T02-Z01 H-SiNP: Cutting Through the Layers Using 29Si MAS and DNP NMR T02-Z01 University of Alberta Activity 2019-09-01 T02-Z01 Phase Evolution in Methylammonium Tin Halide Perovskites with Variable Temperature Solid-State 119Sn NMR Spectroscopy T12-P02, T12-P04, T12-Z01, T12-Q01 University of Alberta Publication 2020-07-01 Michelle Ha, Abhoy Karmakar, Guy Bernard, Enoc Basilio, Arun Krishnamurthy, Abdelrahman M Askar, Karthik Shankar, Scott Kroeker,
Michaelis, V. T12-P02, T12-P04, T12-Z01, T12-Q01 Hydride Terminated SiNP:Cutting through the Layers Using 29Si MAS and DNP NMR Spectroscopy T02-Z01, T06-Z01 University of Alberta Activity 2020-02-01 T02-Z01, T06-Z01 President’s Doctoral Prize of Distinction T12-Q01 Award 2020-05-20 Michelle Ha
T12-Q01 2D C-N Semiconductors: Graphitic, Earth-Abundant Photocatalysts with Tunable Bandgaps T12-P02 Activity 2018-03-14 Pawan Kumar, Ujwal Thakur, Guy Bernard, Ehsan Vahidzadeh, Karthik Shankar
T12-P02 Atomistic insights on Halide Composition in Mixed Halide Perovskite Systems: 207Pb solid-state NMR perspective T12-P02 University of Alberta Activity 2017-11-16 " Abdelrahman Askar
" , Abhoy Karmakar, Benjamin Wiltshire, Sahil Patel, Guy Bernard,
Michaelis, V. , Karthik Shankar
T12-P02 C3N5: A Low Bandgap Semiconductor Containing an Azo-linked Carbon Nitride Framework for Photocatalytic, Photovoltaic and Adsorbent Applications Modification of carbon nitride based polymeric 2D materials for tailoring their optical, electronic and chemical properties for various applications has gained significant interest. The present report demonstrates the synthesis of a novel modified carbon nitride framework with a remarkable 3:5 C:N stoichiometry (C3N5) and an electronic bandgap of 1.76 eV, by thermal deammoniation of melem hydrazine precursor. Characterization revealed that in C3N5 polymer, two s-heptazine units are bridged together with azo linkage, which constitutes an entirely new and different bonding fashion from g-C3N4 where three heptazine units are linked together with tertiary nitrogen. Extended conjugation due to overlap of azo nitrogens and increased electron density on heptazine nucleus due to the aromatic π network of heptazine units lead to an upward shift of the valence band maximum resulting in bandgap reduction down to 1.76 eV. XRD, He-ion imaging, HR-TEM, EELS, PL, fluorescence life time imaging, Raman, FTIR, TGA, KPFM etc clearly show that the properties of C3N5 are distinct from pristine carbon nitride (g-C3N4). When used as an electron transport layer (ETL) in MAPbBr3 based halide perovskite solar cells, C3N5 outperformed g-C3N4, in particular generating an open circuit photovoltage as high as 1.3 V, while C3N5 blended with MAxFA1-xPb(I0.85Br0.15)3 perovskite active layer achieved a photoconversion efficiency (PCE) up to 16.7 %. C3N5 was also shown to be an effective visible light sensitizer for TiO2 photoanodes in photoelectrochemical water splitting. Due to its electron- rich character, the C3N5 material displayed instantaneous adsorption of methylene blue from aqueous solution reaching complete equilibrium within 10 min, which is significantly faster than pristine g-C3N4 and other carbonbased materials. C3N5 coupled with plasmonic silver nanocubes promotes plasmon-exciton coinduced surface catalytic reactions reaching completion at much low laser intensity (1.0 mW) than g-C3N4 which showed sluggish performance even at high laser power (10.0 mW). The relatively
narrow bandgap and 2D structure of C3N5 make it an interesting air-stable and temperature resistant semiconductor for optoelectronic applications while its electron- rich character and intrasheet cavity make it an attractive supramolecular adsorbent for environmental applications. T12-P02, T12-Z01, T12-Q01 University of Alberta Publication 2019-02-14 Pawan Kumar, Ehsan Vahidzadeh, Ujwal Thakur, Piyush Kar, Kazi Alam, Ankur Goswami, Najia Mahdi,
" Kai Cui
" , Guy Bernard,
Michaelis, V. , Karthik Shankar
T12-P02, T12-Z01, T12-Q01 In Search of Coloured Intermetallics Contributed poster.T12-P01, T12-Z01 University of Alberta Activity 2018-05-29 T12-P01, T12-Z01 Noble Metal Free, Visible Light Driven Photocatalysis Using TiO2 Nanotube Arrays Sensitized by P-doped C3N4 Quantum Dots Bulk g-C3N4 is an earth-abundant, easily synthesizable, and exceptionally stable photocatalyst with an electronic bandgap of 2.7 eV. Herein, the concepts of P-doping and size quantization are combined to synthesize highly fluorescent P-doped carbon nitride quantum dots (CNPQDs) with a bandgap of 2.1 eV. CNPQDs are hosted on anatase-phase and rutilephase TiO2 nanotube array scaffolds, and examined as photoanodes for sunlight-driven water-splitting and as photocatalysts for surface catalytic reactions. Square-shaped rutile phase TiO2 nanotube arrays (STNAs) decorated with CNPQDs (CNPQD-STNA) generate 2.54 mA cm−2 under AM1.5 G simulated sunlight. A champion hydrogen evolution rate of 22 µmol h−1 corresponds to a Faradaic efficiency of 93.2%. In conjunction with Ag nanoparticles (NPs), the CNQPD-STNA hybrid is also found to be an excellent plexcitonic photocatalyst for the visible light-driven transformation of 4-nitrobenzenethiol (4-NBT) to dimercaptoazobenzene (DMAB), producing reaction completion at a laser power of 1 mW (532 nm) while Ag NP/TNA and Ag NP/STNA photocatalysts cannot complete this transformation even at 10 mW laser power. The results point the way forward
for photochemically robust, noble metal free, visible light harvesting photoacatalysts based on nanostructured heterojunctions of graphenic frameworks with TiO2.T12-P02, T12-P03 University of Alberta Publication 2019-10-17 Pawan Kumar, Piyush Kar, Ajay Manuel, Ujwal Thakur, Kazi Alam, Yun Zhang, Ryan Kisslinger, Sheng Zeng,
" Kai Cui
" , Guy Bernard,
Michaelis, V. , Karthik Shankar
T12-P02, T12-P03 Co-aromatization of methane with propane over Zn/HZSM -5: The methane reaction pathway and the effect of Zn distribution T02-Z01 University of Alberta Publication 2019-08-01 Peng He, Jack S Jarvis, Shijun Meng, Qingyin Li, Guy Bernard, Lijia Liu, Xiaohui Mao, Zhao Jiang, Hongbo Zeng,
Michaelis, V. , Hua Song
T02-Z01 Impact of Al sites on the methane co-aromatization with alkanes over Zn/HZSM -5 T02-Z01 University of Alberta Publication 2019-02-01 Peng He, Aiguo Wang, Shijun Meng, Guy Bernard, Lijia Liu,
Michaelis, V. , Hua Song
T02-Z01 Tailorable Indirect to Direct Band-Gap Double Perovskites with Bright White-Light Emission: Decoding Chemical Structure Using Solid-State NMR T12-Z01, T12-Q01 University of Alberta Publication 2020-05-01 Abhoy Karmakar, Guy Bernard, Al Meldrum, Anton Oliynyk,
Michaelis, V. T12-Z01, T12-Q01 Lead-207 NMR Spectroscopy at 1.4 T: Application of Benchtop Instrumentation to a Challenging I = \textonehalf Nucleus T12-Z01, T12-Q01 University of Alberta Publication 2020-05-01 T12-Z01, T12-Q01 Influence of hidden halogen mobility on local structure of CsSn(Cl1-xBrx)3 mixed-halide perovskites by solid-state NMR T12-Z01, T12-Q01 University of Alberta Publication 2021-01-01 T12-Z01, T12-Q01 High-Capacitance Pseudocapacitors from Li+ Ion Intercalation in Nonporous, Electrically Conductive 2D Coordination Polymers T06-Z01 University of Alberta Publication 2021-02-01 " Mircea Dincă
" ,
Michaelis, V. , Madhu Sudan Chaudhary, Jeffrey T Miller, Guy Bernard, Nicole J Libretto,
" Tianyang Chen
" ,
" Jin-Hu Dou
" ,
" Harish Banda
" T06-Z01 Photocatalytic mechanism control and study of carrier dynamics in CdS@C3N5 core-shell nanowires We present a potential solution to the problem of extraction of photogenerated holes from CdS nanocrystals and nanowires. The nanosheet form of C3N5 is a low bandgap (Eg = 2.03 eV), azo-linked graphenic carbon nitride framework formed by the polymerization of melem hydrazine (MHP). C3N5 nanosheets were either wrapped around CdS nanorods (NRs) following the synthesis of pristine chalcogenide or intercalated among them by an in situ synthesis protocol to form two kinds of heterostructures, CdS-MHP and CdS-MHPINS respectively. CdS-MHP improved the photocatalytic degradation rate of 4-nitrophenol by nearly an order of magnitude in comparison to bare CdS NRs. CdS-MHP also enhanced the sunlight-driven photocatalytic activity of bare CdS NWs for the decolorization of rhodamine B (RhB) by a remarkable 300% through the improved extraction and utilization of photogenerated holes due to surface passivation. More interestingly, CdS-MHP provided reaction pathway control over RhB degradation. In the absence of scavengers, CdS-MHP degraded RhB through the N-deethylation pathway. When either hole scavenger or electron scavenger was added to the RhB solution, the photocatalytic activity of CdS-MHP remained mostly unchanged while the degradation mechanism shifted to the chromophore cleavage (cycloreversion) pathway. We investigated the optoelectronic properties of CdS-C3N5 heterojunctions using density functional theory (DFT) simulations, FDTD simulations, time-resolved terahertz spectroscopy (TRTS) and photoconductivity measurements. TRTS indicated high carrier mobilities > 450 cm2Vs-1 and carrier relaxation times > 60 ps for CdS-MHP while CdS-MHPINS exhibited much lower mobilities < 150 cm2Vs-1 and short carrier relaxation times <20 ps. Hysteresis in the photoconductive J-V characteristics of CdS NWs disappeared in CdS-MHP confirming surface passivation. Dispersion-corrected DFT simulations indicated a delocalized HOMO and a LUMO localized on C3N5 in CdS-MHP. C3N5, with its extended π-conjugation and low bandgap can function as a shuttle to extract carriers and excitons in nanostructured heterojunctions, and enhance performance in optoelectronic devices. Our results demonstrate how carrier dynamics in core-shell heterostructures can be manipulated to achieve control over the reaction mechanism in photocatalysis. T12-P02, T12-P03, T06-Z01, T12-Z01 University of Alberta Publication 2021-04-30 Kazi Alam, Charles Jensen, Pawan Kumar, Riley Hooper, Guy Bernard, Aakash Patidar, Ajay Manuel,
" N Amer
" ,
" A Palmgren
" , Narendra Chaulagain, David Purschke, John Garcia, Phillip Suwan Kirwin, Lian Shoute,
" K. Cui
" ,
" S. Gusarov
" ,
" A. Kobryn
" ,
Michaelis, V. , Frank Hegmann, Karthik Shankar
T12-P02, T12-P03, T06-Z01, T12-Z01 Coloured intermetallic compounds LiCu2Al and LiCu2Ga This paper describes the search for coloured metallic substances, which are very rare (in contrast to coloured semiconductors or insulators, which are typically compounds with significant ionic character, such as halides and oxides). T12-P01 University of Alberta Publication 2020-09-02 Vidyanshu Mishra, Abishek K Iyer, Dundappa Mumbaraddi, Anton Oliynyk,
" Guillaume Zuber
" ,
" Aurélien Boucheron
" ,
" Grygoriy Dmytriv
" , Guy Bernard,
Michaelis, V. ,
Mar, A. T12-P01 Revealing the Local Sn and Pb Arrangements in CsSnxPb1–xBr3 Perovskites with Solid-State NMR Spectroscopy T12-Z01 University of Alberta Publication 2021-01-25 T12-Z01 High-Capacitance Pseudocapacitors from Li$\less$sup$\greater$$\mathplus$$\less$/sup$\greater$ Ion Intercalation in Nonporous, Electrically Conductive 2D Coordination Polymers T02-Z01 University of Alberta Publication 2021-02-01 Harish Banda, Jin-Hu Dou, Tianyang Chen, Nicole J Libretto, Madhu Sudan Chaudhary, Guy Bernard, Jeffrey T Miller,
Michaelis, V. ,
" Mircea Dincă
" T02-Z01 Investigating ordering in chalcogenide solid electrolytes using solid-state NMR spectroscopy T12-P01 University of Alberta Activity 2022-06-15 T12-P01 Drop that activation energy: Tetragonal to cubic transformations in Na3PS4−xSex for solid state sodium ion battery materials T12-P01 University of Alberta Publication 2023-12-14 Madhu Sudan Chaudhary, Arkadii Pominov, Dundappa Mumbaraddi,
" Bryce Allen
" ,
" Jan Meyer
" , Anna Maria Kirchberger, Guy Bernard,
" Tom Nilges
" ,
Mar, A. ,
Michaelis, V. T12-P01 Tunable Absorption and Emission in Mixed Halide Bismuth Oxyhalides for Photoelectrochemical Water Splitting Layered materials such as bismuth oxyhalides (especially BiOBr and BiOI) are the focus of research attention as photocatalysts due to their visible light activity, unique electronic structure, excellent chemical and physical stability, and internal electric field effect. We report the solvothermal synthesis of BiOX solid solutions with continuously tunable optical absorption and photoluminescence spectra. We employed solid-state nuclear magnetic resonance (SSNMR) characterization to probe the local environment around Bi atoms. We determined that the synthesized BiOX solid solutions exhibit good agreement with Vegard’s law through refinement of the lattice parameters using powder X-ray diffraction (PXRD) and complementary atomic-level 209Bi SSNMR spectroscopy. The solid solution strategy makes it possible to modulate the light absorption of BiOX and tune the redox potentials corresponding to the electronic band edges to drive chemical reactions. The BiOX solid solutions demonstrated superior performance in sunlight-driven photoelectrochemical and photocatalytic water splitting. The best performing solid solution generated a photocurrent density of 1.5 mA cm–2 and a H2 evolution rate of 16.32 μmol g–1 h–1 for photoelectrochemical water splitting and photocatalytic hydrogen generation, respectively, and the enhanced performance is attributed to a higher specific surface area, a shorter carrier transit distance, and a higher electron density. The approximate order of magnitude performance improvement compared to pristine BiOBr and BiOI photoanodes was primarily due to optimal light harvesting combined with adequate thermodynamic driving force to drive water oxidation and proton reduction.T12-P02, T12-P03 University of Alberta Publication 2024-01-01 Md Masud Rana, Kazi Alam, Narendra Chaulagain, John Garcia, Navneet Kumar, Damini Vrushabendrakumar, Harshitha Rajashekhar, Guy Bernard, Al Meldrum,
Michaelis, V. , Karthik Shankar
T12-P02, T12-P03 Liquid Crystalline Lithium-Ion Electrolytes Derived from Biodegradable Cyclodextrin T06-Z01 University of Alberta Publication 2019-04-17 Haoyang Yu, P L Champagne,
" D Ester
" , Amit Bhattacharya,
" K Hofstetter
" ,
" C Zellman
" ,
" S Bag
" ,
" S Trudel
" ,
Michaelis, V. ,
" VE Williams
" ,
" V Thangadurai
" ,
" C Ling
" T06-Z01 Experimental validation of high thermoelectric performance in RECuZnP2 predicted by high-throughput DFT calculations This investigation of RECuZnP2 (RE = rare earth) is the first in-depth study of transport properties in quaternary CaAl2Si2-type compounds, a promising class of thermoelectric materials. The new concept demonstrated is the combined application of DFT calculations with advanced physics-based scattering calculations to gain insight on the underlying mechanisms of thermoelectric properties. In contrast to existing research, which is impeded by restrictions of conventional DFT methods, our approach accurately models thermoelectric properties of complex materials exhibiting disorder, a pervasive feature of real materials. The results directly challenge the usual assumption that acoustic phonon scattering is the limiting factor of electron transport in most thermoelectric materials; instead, polar optical phonon scattering is likely more important than previously believed. Moreover, the calculations shed light on the unexpectedly low lattice thermal conductivity in RECuZnP2: despite high bulk moduli and speeds of sounds, strongly anharmonic bonding can significantly reduce the thermal conductivity. These insights on the mechanisms of electron and heat transport have broader implications to the materials science community, by guiding researchers to discover more efficient thermoelectric materials in applying new concepts to optimize their properties. The low computational cost of these methods could also herald an exciting era of DFT-guided materials discovery.T12-P01, T12-Z01 University of Alberta Publication 2020-11-04 Jan Poehls,
" Sevan Chanakian
" ,
" Junsoo Park
" , Alex M Ganose,
" Alexander Dunn
" , Nick Friesen, Amit Bhattacharya,
" Brea Hogan
" ,
" Sabah Bux
" ,
" Anubhav Jain
" ,
Mar, A. ,
" Alexandra Zevalkink
" T12-P01, T12-Z01 Experimental Validation of High Thermoelectric Performance in RECuZnP2 Predicted by High-Throughput DFT Calculations Oral presentation given by Jan Poehls at the Virtual Conference on Thermoelectrics 2020T12-P01, T12-Z01 University of Alberta Activity 2020-07-21 Jan Poehls,
" Sevan Chanakian
" ,
" Junsoo Park
" ,
" Alex Ganose
" ,
" Alex Dunn
" , Nick Friesen, Amit Bhattacharya,
" Anubhav Jain
" ,
" Alexandra Zevalkink
" ,
Mar, A. T12-P01, T12-Z01 Mere anarchy is loosed: Structural disorder in Cu2Zn1-xCdxSnS4 T12-P01 University of Alberta Publication 2021-06-03 T12-P01 Mixing, Domains, and Fast Li-Ion Dynamics in Ternary Li–Sb–Bi Battery Anode Alloys Publication of original research T12-P04 University of Alberta Publication 2022-02-01 Michaelis, V. , Jillian Mary Buriak, Madhu Sudan Chaudhary, Amit Bhattacharya,
" Peter Kalisvaart
" T12-P04 Mixing, Domains, and Fast Li-Ion Dynamics in Ternary Li\textendash Sb\textendashBi Battery Anode Alloys T06-Z01 University of Alberta Publication 2022-02-01 W Peter Kalisvaart, Madhu Sudan Chaudhary, Amit Bhattacharya,
Michaelis, V. , Jillian Mary Buriak
T06-Z01 Mercurial possibilities: determining site distributions in Cu2HgSnS4 using 63/65Cu, 119Sn, and 199Hg solid-state NMR spectroscopy T12-P01, T12-P02 University of Alberta Publication 2022-09-21 T12-P01, T12-P02 Effect of aliovalent bismuth substitution on structure and optical properties of CsSnBr3 T12-P01, T12-P02 University of Alberta Publication 2023-04-19 Madhu Sudan Chaudhary, Abhoy Karmakar, Vidyanshu Mishra, Amit Bhattacharya, Dundappa Mumbaraddi,
Mar, A. ,
Michaelis, V. T12-P01, T12-P02 Mechanochemical synthesis of 0D and 3D cesium lead mixed halide perovskites T12-Z01, T12-Q01 University of Alberta Publication 2019-04-03 Abhoy Karmakar, Mya S Dodd, Xiaoyue Zhang, Meagan S Oakley, Mariusz Klobukowski,
Michaelis, V. T12-Z01, T12-Q01 2019 Petro Canada Young Innovators T02-Z01 University of Alberta Award 2019-03-01 T02-Z01 Copper-doped double perovskites and uses thereof (USPTO) Patent No.: US 11,479,477 B2
Date of Patent: 2022-10-25
USPTO Application Serial No. 16/909,072
Filed on: 2020-06-23
Abstract: The present application relates to copper-doped double perovskites, for example, copper-doped double perovskites of the formula (I) and to uses thereof, for example as low-bandgap materials such as a semiconducting material in a device. The present application also relates to methods of tuning the bandgap of a Cs.sub.2SbAgZ.sub.6 double perovskite (for example, wherein Z is Cl) comprising doping the double perovskite with copper. Cs.sub.2Sb.sub.1-aAg.sub.1-bCu.sub.2xZ.sub.6 (I)T12-Q01 University of Alberta IP Management 2022-10-25 T12-Q01 Coloured intermetallic compounds Li2ZnGa and Li2ZnIn This manuscript describes continuing efforts in our research group to identify new coloured intermetallics, which remaining exceedingly rare (perhaps ~102, or <1% of known intermetallic compounds) and largely limited to combinations with very expensive precious metals (e.g., Au, Pt). The origin for the appearance of colour in these compounds differs from the more familiar cases of inorganic semiconductors or insulators because there are no band gaps, charge transfer, or d-d/f-f transitions. The combination of colour and metallic lustre makes these compounds particularly attractive as decorative coatings and jewellery; more ambitiously, they may prove to be possible candidates for plasmonic materials. Our hypothesis is that Li-containing intermetallics synthesized with less expensive elements (e.g., Cu, Zn) would possess similar crystal and electronic structures as the previously known analogues, and thus be fruitful targets for new, more accessible coloured intermetallics. We report here the two new coloured intermetallics Li2ZnGa and Li2ZnIn, determine their crystal structures by powder X-ray diffraction methods, confirm the location of Li atoms (difficult to detect by XRD) through solid state 7Li NMR spectroscopy, quantitatively characterize the colour through optical reflectance measurements and extraction of CIE colour coordinates, and perform electronic structure calculations.T12-P01 University of Alberta Publication 2021-11-30 Mohammad Jomaa, Vidyanshu Mishra, Dundappa Mumbaraddi, Madhu Sudan Chaudhary,
" Grygoriy Dmytriv
" ,
Michaelis, V. ,
Mar, A. T12-P01 Investigation of Li-Zn-X (X = Ga, In) coloured intermetallics T12-P01, T12-Z01 University of Alberta Activity 2021-07-28 Mohammad Jomaa, Vidyanshu Mishra, Dundappa Mumbaraddi, Madhu Sudan Chaudhary,
Michaelis, V. ,
Mar, A. T12-P01, T12-Z01 Tailoring B-doped silicon nanocrystal surface chemistry via phosphorus pentachloride – mediated surface alkoxylation T06-Z01, T12-Z01 University of Alberta Publication 2021-01-01 T06-Z01, T12-Z01 Exploring Structural Nuances in Germanium Halide Perovskites Using Solid-State $\less$sup$\greater$73$\less$/sup$\greater$Ge and $\less$sup$\greater$133$\less$/sup$\greater$Cs NMR Spectroscopy T06-Z01 University of Alberta Publication 2022-02-01 T06-Z01 True colours shining through: Determining site distributions in coloured Li-containing quaternary Heusler compounds T12-P01 University of Alberta Publication 2022-06-28 Mohammad Jomaa, Vidyanshu Mishra, Madhu Sudan Chaudhary, Dundappa Mumbaraddi,
Michaelis, V. ,
Mar, A. T12-P01 Structure and optical properties of LixAg1-xGaSe2 and LixAg1-xInSe2 T12-P01 University of Alberta Publication 2023-04-28 Mohammad Jomaa, Vidyanshu Mishra, Dundappa Mumbaraddi, Ritobroto Sikdar,
" Diganta Sarkar
" ,
" Mengran Sun
" ,
" Jiyong Yao
" ,
Michaelis, V. ,
Mar, A. T12-P01 Cerium-containing chalcohalides as tunable photoluminescent materials T12-P01 University of Alberta Activity 2022-06-16 Dundappa Mumbaraddi, Vidyanshu Mishra, Mohammad Jomaa, Abhoy Karmakar, Andrew P Grosvenor,
Michaelis, V. , Al Meldrum,
Mar, A. T12-P01 Luminescence properties of rare-earth chalcohalides RE3Ge2-xSixS8I (RE = La, Ce, Pr) and Ce3Si2S8-ySeyI for potential application in phosphor-converted white LEDs T12-P01 University of Alberta Activity 2022-07-27 Dundappa Mumbaraddi, Vidyanshu Mishra, Mohammad Jomaa, Xiaoyuan Liu, Abhoy Karmakar,
" Sambhavi Thirupurasanthiran
" , Al Meldrum, Andrew P Grosvenor,
Michaelis, V. ,
Mar, A. T12-P01 Controlling the luminescence of rare-earth chalcogenide iodides RE3(Ge1–xSix)2S8I (RE = La, Ce, and Pr) and Ce3Si2(S1–ySey)8I T12-P01 University of Alberta Publication 2023-07-18 Dundappa Mumbaraddi, Vidyanshu Mishra, Mohammad Jomaa, Xiaoyuan Liu, Abhoy Karmakar,
" Sambhavi Thirupurasanthiran
" ,
Michaelis, V. , Andrew P Grosvenor, Al Meldrum,
Mar, A. T12-P01 Mechanochemistry in sodium thioantimonate solid electrolytes: Effects on structure, morphology, and electrochemical performance T12-P01 University of Alberta Publication 2023-08-09 Fuwei Wen, Geng Xie,
" Ning Chen
" , Qichao Wu, Madhu Sudan Chaudhary, Xiang You,
Michaelis, V. ,
Mar, A. ,
Sang, L. T12-P01 Controlling the luminescence of rare-earth chalcohalides Ce3Ge2–xSixS8I and Ce3Si2S8–ySeyI T12-P01 University of Alberta Activity 2023-06-06 Dundappa Mumbaraddi, Vidyanshu Mishra, Mohammad Jomaa, Xiaoyuan Liu, Abhoy Karmakar,
" Sambhavi Thirupurasanthiran
" , Al Meldrum, Andrew P Grosvenor,
Michaelis, V. ,
Mar, A. T12-P01 Effect of Li Addition on the Nonlinear Optical Activity of Ag1-xLixMSe2 (M = Ga, In) T12-P01 University of Alberta Activity 2023-06-08 Mohammad Jomaa, Vidyanshu Mishra, Dundappa Mumbaraddi, Ritobroto Sikdar,
" Diganta Sarkar
" ,
" Mengran Sun
" ,
" Jiyong Yao
" ,
Michaelis, V. ,
Mar, A. T12-P01 Effect of Li Addition on the Nonlinear Optical Activity of Ag1-xLixMSe2 (M = Ga, In) T12-P01 University of Alberta Activity 2023-08-01 Mohammad Jomaa, Vidyanshu Mishra, Dundappa Mumbaraddi, Ritobroto Sikdar,
" Diganta Sarkar
" ,
" Mengran Sun
" ,
" Jiyong Yao
" ,
Michaelis, V. ,
Mar, A. T12-P01 Are selenides the same as sulfides? Structure, spectroscopy, and properties of narrow-gap rare-earth semiconductors RE2Sn(S1-xSex)5 (RE = La, Ce; x = 0-0.8) T12-P01 University of Alberta Publication 2024-05-24 T12-P01 In search of coloured alloys resembling gold: Structure and optical properties of LiCu2Ga1−xAlx and Li(Cu1–yNiy)2Ga T12-P01 University of Alberta Publication 2024-07-20 Mohammad Jomaa, Dundappa Mumbaraddi, Vidyanshu Mishra, Madhu Sudan Chaudhary,
" Brenton Mah
" , Diane Delaruelle,
Michaelis, V. ,
Mar, A. T12-P01 Structure and optical properties of LixAg1–xAlSe2 T12-P01 University of Alberta Publication 2024-07-29 Mohammad Jomaa, Vidyanshu Mishra, Dundappa Mumbaraddi,
" Diganta Sarkar
" , Ritobroto Sikdar,
" Mengran Sun
" ,
" Jiyong Yao
" ,
Michaelis, V. ,
Mar, A. T12-P01 Phase transformations in lithium-containing chalcogenides T12-P01 University of Alberta Activity 2024-06-04 " Pritam Das
" , Dundappa Mumbaraddi, Vidyanshu Mishra,
" Diganta Sarkar
" ,
" Mohammed Jomaa
" ,
Michaelis, V. ,
Mar, A. T12-P01 Cellulose-Encapsulated Composite Electrolyte Design: Toward Chemically and Mechanically Enhanced Solid-Sodium Batteries T06-A06 University of Alberta Publication 2024-06-12 " Shu Dong
" , Geng Xie,
" Shihong Xu
" , XueHai Tan, Madhu Sudan Chaudhary,
" Yue Zhang
" , Runqi Wu, Fuwei Wen,
" Cagri Ayranci
" ,
Michaelis, V. ,
" Amanda Quirk
" , Scott M Rosendahl,
" Jian Liu
" , Michael D Fleischauer,
Sang, L. T06-A06 Influence of Aliovalent Substitution on Structure and Dynamics in Sodium Halide Na3-2xY1-xNbxCl6Solid Electrolytes Sodium halide solid electrolytes are garnering increased interest because of their synthetic flexibility to incorporate a variety of cations, thereby altering their structure and properties. Aliovalent substitution is said to increase ionic conductivity by promoting polyanion rotation. We synthesize and assess a series of Na(3-2x)Y(1-x)Nb(x)Cl(6), probing their complex structures using complementary powder X-ray diffraction and variable-temperature 1D and 2D solid-state nuclear magnetic resonance spectroscopy. The bond- valence energy landscapes of the end members are visualized to reveal potential Na-ion transport pathways. A structural threshold is reached for Na2Y0.5Nb0.5Cl6, revealing a limit for Nb polyhedral distortion while the unit cell volume is retained up to 50% Nb substitution. Na2Y0.5Nb0.5Cl6 shows the greatest RT ionic conductivity enhancement in the series, from 10–11 S cm–1 to 10–5 S cm–1.T06-Z01-LBP1 University of Alberta Publication 2025-12-30 Brian Buu Phan,
" Tso Shuen
" , Dmitry Vrublevskiy,
" Qingyu Yan
" ,
Michaelis, V. T06-Z01-LBP1 Atomic Cartography of High‐Entropy Cs2BCl6 Perovskite‐Inspired Materials: The Vital Role of Solid‐State NMR Spectroscopy in Identifying Elemental Disorder T06-Z01-LBP1 University of Alberta Publication 2025-01-01 Brian Buu Phan, Diganta Sarkar, Kishor Das, Riley Hooper, Trinanjan Dey, Michael J Ferguson, Xiaolong Liu,
Veinot, J. ,
Michaelis, V. T06-Z01-LBP1 Optimizing low-temperature defect engineering in TiO2 nanosheets for enhanced photocatalytic water splitting University of Alberta Publication 2026-01-01 Sadegh Pour-Ali, Diganta Sarkar, Ula Suliman, Majid Shahsanaei,
Michaelis, V. , Shiva Mohajernia
