A5072522213- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Photochemistry and Electron Transfer Studies
- Porphyrin and Phthalocyanine Chemistry
- Photosynthetic Processes and Mechanisms
- Molecular Junctions and Nanostructures
- Spectroscopy and Quantum Chemical Studies
- Luminescence and Fluorescent Materials
- Organic Electronics and Photovoltaics
- Perovskite Materials and Applications
- Conducting polymers and applications
- Electron Spin Resonance Studies
- Photoreceptor and optogenetics research
- DNA and Nucleic Acid Chemistry
- Advanced biosensing and bioanalysis techniques
- Magnetism in coordination complexes
- Crystallography and molecular interactions
- Supramolecular Chemistry and Complexes
- Organic Light-Emitting Diodes Research
- Radical Photochemical Reactions
- Metal-Organic Frameworks: Synthesis and Applications
- Electrochemical Analysis and Applications
- Electrocatalysts for Energy Conversion
- Synthesis and Properties of Aromatic Compounds
- Quantum Dots Synthesis And Properties
Northwestern University
2016-2025
Argonne National Laboratory
2011-2023
National Renewable Energy Laboratory
1997-2023
Friedrich-Alexander-Universität Erlangen-Nürnberg
2001-2023
Nanyang Technological University
2023
Monash University
2023
University of Toronto
2023
University of Oxford
2020-2023
Royal Society of Chemistry
2023
Technische Universität Braunschweig
2023
In natural photosynthesis, organisms optimize solar energy conversion through organized assemblies of photofunctional chromophores and catalysts within proteins that provide specifically tailored environments for chemical reactions. As with their counterparts, artificial photosynthetic systems practical fuels production must collect light energy, separate charge, transport charge to catalytic sites where multielectron redox processes will occur. While encouraging progress has been made on...
Structural and electronic criteria for ambient stability in n-type organic materials field-effect transistors (OFETs) are investigated by systematically varying LUMO energetics molecular substituents of arylene diimide-based materials. Six OFETs on n+-Si/SiO2 substrates exhibit OFET response parameters as follows: N,N'-bis(n-octyl)perylene-3,4:9,10-bis(dicarboximide) (PDI-8): mu = 0.32 cm2 V(-1) s(-1), Vth 55 V, I(on)/I(off) 10(5); N,N'-bis(n-octyl)-1,7-...
Taking up the semiconducting baton: Organic field-effect transistors fabricated with a new class of extremely electron-deficient cyanated perylene diimides are air-stable and exhibit n-type mobilities as high 0.64 cm2 V−1 s−1 (see scheme). Devices can be from vapor-deposited solution-cast films well top- bottom-contact electrode configurations. Supporting information for this article is available on WWW under http://www.wiley-vch.de/contents/jc_2002/2004/z461324_s.pdf or author. Please note:...
The three-dimensional hybrid organic-inorganic perovskites have shown huge potential for use in solar cells and other optoelectronic devices. Although these materials are under intense investigation, derivative with lower dimensionality emerging, offering higher tunability of physical properties new capabilities. Here, we present two series two-dimensional (2D) that adopt the Dion-Jacobson (DJ) structure type, which first complete homologous reported halide perovskite chemistry. Lead iodide...
The radical anions of aromatic diimides have been implicated recently in a wide variety photochemical electron transfer reactions. Photoexcitation these produces powerfully reducing species. Yet, the properties π* excited doublet states organic remain obscure. three imides with increasingly larger π systems, N-(2,5-di-tert-butylphenyl)phthalimide, 1, N-(2,5-di-tert-butylphenyl)-1,8-naphthalimide, 2, and N-(2,5-di-tert-butylphenyl)perylene-3,4-dicarboximide, 3, as well corresponding diimides,...
Hybrid inorganic-organic perovskites are developing rapidly as high performance semiconductors. Recently, two-dimensional (2D) were found to have white-light, broadband emission in the visible range that was attributed mainly role of self-trapped excitons (STEs). Here, we describe three new 2D lead bromide incorporating a series bifunctional ammonium dications templates which also emit white light: (1) α-(DMEN)PbBr4 (DMEN = 2-(dimethylamino)ethylamine), adopts unique corrugated layered...
Tin-based halide perovskite materials have been successfully employed in lead-free solar cells, but the tendency of these to form leakage pathways from p-type defect states, mainly Sn4+ and Sn vacancies, causes poor device reproducibility limits overall power conversion efficiencies (PCEs). Here, we present an effective process that involves a reducing vapor atmosphere during preparation Sn-based cells solve this problem, using MASnI3, CsSnI3, CsSnBr3 as representative absorbers. This...
The synthesis and metal ion responsive properties of two 2,2'-bipyridyl-phenylene-vinylene-based polymers is reported. These are designed to be partially conjugated in their metal-free state fully when exposed ions so that the ion-induced conjugation enhancement can transduced into a measurable signal. It found these exhibit highly ionochromic effects with wide variety transition main group excluding alkali alkaline earth groups. For instance, both absorption fluorescence emission bands upon...
The dynamics of photoinduced charge separation and recombination processes in synthetic DNA hairpins have been investigated by means femtosecond transient absorption spectroscopy. driving force distance dependence charge-transfer involving singlet acceptors nucleobase donors are consistent with a single-step superexchange mechanism which the electronic coupling between donor acceptor is strongly dependent. reversible hole transport primary guanine nearby GG or GGG sequences has also...
The distance dependence of photoinduced electron transfer in duplex DNA was determined for a family synthetic hairpins which stilbene dicarboxamide forms bridge connecting two oligonucleotide arms. Investigation the fluorescence and transient absorption spectra these established that no occurs hairpin has six deoxyadenosine-deoxythymidine base pairs. However, introduction single deoxyguanosine-deoxycytidine pair resulted distance-dependent quenching formation anion radical. Kinetic analysis...
Gamma-ray detection and spectroscopy is the quantitative determination of their energy spectra, critical value critically important in diverse technological scientific fields. Here we report an improved melt growth method for cesium lead bromide a special detector design with asymmetrical metal electrode configuration that leads to high performance at room temperature. As-grown centimeter-sized crystals possess extremely low impurity levels (below 10 p.p.m. total 69 elements) detectors...
An electron donor-acceptor-donor molecule consisting of two porphyrin donors rigidly attached to the two-electron acceptor N,N ′-diphenyl-3,4,9,10-perylenebis(dicarboximide) acts as a light intensity—dependent molecular switch on picosecond time scale. Excitation porphyrins within this with subpicosecond laser pulses results in single or double reduction depending intensity. The singly and doubly reduced acceptors absorb strongly at 713 546 nanometers, respectively. Because these absorption...
Two-dimensional (2D) hybrid halide perovskites come as a family (B)2(A)n−1PbnX3n+1 (B and A= cations; X= halide). These are promising semiconductors for solar cells optoelectronic applications. Among the fascinating properties of these materials is white-light emission, which has been mostly observed in single-layered 2D lead bromide or chloride systems (n = 1), where broad emission comes from transient photoexcited states generated by self-trapped excitons (STEs) structural distortion. Here...
Molecules designed to carry out photochemical energy conversion typically employ several sequential electron transfers, as do photosynthetic proteins. Yet, these molecules not achieve the extensive charge transport characteristic of semiconductor devices. We have prepared a large molecule in which four perylene-3,4:9,10-tetracarboxydiimide (PDI) that both collect photons and accept electrons are attached central zinc 5,10,15,20-tetraphenylporphyrin (ZnTPP) donor. This self-assembles into...
Low electrical resistivity (high dark carrier concentration) of CH3NH3SnI3 often leads to short-circuiting in solar cells, and appropriate thin-film modifications are required ensure functional devices. The long-term durability organic–inorganic perovskite cells necessitates the protection thin films from moisture prevent material decomposition. Herein, we report that stability two-dimensional (2D) Ruddlesden–Popper (CH3(CH2)3NH3)2(CH3NH3)n−1SnnI3n+1 perovskites considerably improved...
High-performance and good-stability hollow Sn-based perovskite solar cells using ethylenediammonium formamidinium cations.