A5054566755- Perovskite Materials and Applications
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Quantum Dots Synthesis And Properties
- Conducting polymers and applications
- Chalcogenide Semiconductor Thin Films
- Organic Electronics and Photovoltaics
- Organic Light-Emitting Diodes Research
- Solid-state spectroscopy and crystallography
- Crystallography and molecular interactions
- Luminescence and Fluorescent Materials
- 2D Materials and Applications
- Covalent Organic Framework Applications
- Molecular Junctions and Nanostructures
- Metal-Organic Frameworks: Synthesis and Applications
- Advanced Chemical Physics Studies
- Thin-Film Transistor Technologies
- Organic and Molecular Conductors Research
- Semiconductor materials and interfaces
- Advanced Thermoelectric Materials and Devices
- Synthesis and Properties of Aromatic Compounds
- Spectroscopy and Quantum Chemical Studies
- Synthesis and Characterization of Heterocyclic Compounds
- Chemical Reactions and Mechanisms
- Phenothiazines and Benzothiazines Synthesis and Activities
Leibniz Institute for Solid State and Materials Research
2023-2025
TU Dresden
2019-2024
Heidelberg University
2013-2021
Kirchhoff (Germany)
2019-2021
Heidelberg University
2019
Centre of Excellence for Advanced Materials
2019
Institute for Physics
2019
Heidelberg (Poland)
2014-2019
Institute of Physical Chemistry
2017
Analytisches Laboratorium
2014-2016
The migration and accumulation of iodide ions create a modulation the respective interfacial barriers causing hysteresis in solar cells based on methylammonium lead perovskites. Iodide are identified as migrating species by measuring temperature dependent current-transients photoelectron spectroscopy. involved changes built-in potential due to ion directly measured electroabsorption
Despite remarkable progress, the performance of lead halide perovskite solar cells fabricated in an inverted structure lags behind that standard architecture devices. Here, we report on a dual interfacial modification approach based incorporation large organic cations at both bottom and top interfaces active layer. Together, this leads to simultaneous improvement open-circuit voltage fill factor devices, reaching maximum values 1.184 V 85%, respectively, resulting champion device efficiency...
Abstract Modern photovoltaic devices are often based on a heterojunction structure where two components with different optoelectronic properties interfaced. The of each side the junction can be tuned by either utilizing materials (for example, donor/acceptor) or doping p–n junction) even varying their dimensionality 3D/2D). Here we demonstrate concept phase (PHJ) solar cells polymorphs same material. We approach forming γ -CsPbI 3 / β perovskite PHJ cells. find that all parameters device...
We describe the modular synthesis of three novel large N-heteroarenes, containing 9, 11, and 13 annulated rings. This system features fused azaacene units to a coronene nucleus. evaluate optical electronic properties solid-state packing targets. The 13-ring N-heteroarene allow fabrication proof-of-concept thin-film transistor. Electron mobilities up 8 × 10–4 cm/(V s) were obtained for polycrystalline films.
The influence of the carbon to nitrogen substitution on photoinduced dynamics TIPS-pentacene was investigated by ultrafast transient absorption measurements spin-coated thin films in visible and near-infrared spectral region. A global target analysis performed provide a detailed picture excited-state dynamics. We found that chemical modification has high impact triplet formation leads shorter dynamics; hence it speeds up singlet fission process. faster relaxation from into manifold implies...
Abstract Field‐effect transistors (FETs) are key elements in modern electronics and hence attracting immense scientific commercial attention. The recent emergence of metal halide perovskite materials their tremendous success the field photovoltaics have triggered exploration application other (opto)electronic devices, including FETs phototransistors. In this review, current status is discussed, challenges highlighted, an outlook for future perspectives provided. First, attention drawn to...
Deposition of perovskite films by antisolvent engineering is a highly common method employed in photovoltaics research. Herein, we report on general that allows for the fabrication efficient solar cells any via manipulation application rate. Through detailed structural, compositional, and microstructural characterization layers fabricated 14 different antisolvents, identify two key factors influence quality layer: solubility organic precursors its miscibility with host solvent(s) precursor...
Abstract Interfacial modification is a key strategy for improving the performance of perovskite photovoltaic devices. While top surface active layer well established, engineering buried interface highly challenging. Here, spontaneous formation 1D/3D heterojunction at by incorporating choline acetate alongside precursors reported. Importantly, extensive spectroscopic and microscopic characterization solid‐state nuclear magnetic resonance experiments demonstrate phase‐pure 1D 3D domains. The...
Femtosecond pump-depletion-probe experiments were carried out in order to shed light on the ultrafast excited-state dynamics of triisopropylsilylethynyl (TIPS)-pentacene and two nitrogen-containing derivatives, namely, diaza-TIPS-pentacene tetraaza-TIPS-pentacene. Measurements performed visible near-infrared spectral range combination with rate model simulations reveal that singlet fission proceeds via extremely short-lived intermediate (1)TT state, which absorbs region only. The T1 → T3...
Raman spectra and DFT calculations show that p-doping of two semiconducting polymers affects mostly their electron-rich thienothiophene units.
Solution-processed quantum dots (QDs) have a high potential for fabricating low-cost, flexible, and large-scale solar energy harvesting devices. It has recently been demonstrated that hybrid devices employing single monovalent cation perovskite solution PbS QD surface passivation exhibit enhanced photovoltaic performance when compared to standard ligand passivation. Herein, we demonstrate the use of triple Cs0.05(MA0.17FA0.83)0.95Pb(I0.9Br0.1)3 composition results in highly efficient cells,...
This work investigates the effect of energetically shallow and deep surface defects in MAPbI<sub>3</sub> films on evolution their photoluminescence properties upon exposure to ambient environment.
Efficient thermally evaporated MA-free perovskite solar cells are developed by optimising their stoichiometry and annealing procedures.
Abstract Thin‐film deposition by thermal evaporation offers many advantages, yet in the field of perovskite photovoltaics solution‐processed devices significantly outperform those fabricated evaporation. Here, high‐quality γ‐CsPbI 3 layers coevaporation PbI 2 and CsI with a small amount phenylethylammonium iodide (PEAI) are deposited. It is demonstrated that addition PEAI into leads to preferred crystal orientation far improved microstructure, columnar domains protrude throughout film's...
In this study, a cation exchange reaction for the synthesis of ternary AgBiS 2 quantum dots is reported. obtained via synthetic route lead to high-efficiency photovoltaic devices.
Quantum chemistry and time-resolved spectroscopy are applied to rationalize how singlet fission (SF) is affected by systematic chemical modifications introduced into phenazinothiadiazoles (PTD). Substitution of the terminal aromatic ring TIPS-tetracene a thiadiazole group leads considerable change in relative energies its S1 T1 states. Thus, contrast TIPS-tetracene, SF becomes exothermic for various PTD derivatives, which show S1–2T1 energy differences as high 0.15 eV. This enables...
Controlling the morphology of metal halide perovskite layers during processing is critical for manufacturing optoelectronics. Here, a strategy to control microstructure solution-processed layered Ruddlesden-Popper-phase films based on phenethylammonium lead bromide ((PEA)
Abstract The stability of perovskite quantum dot solar cells is one the key challenges this technology. This study reveals unique degradation behavior cesium lead triiodide (CsPbI 3 ) cells. For first time, it shown that oxygen‐induced and performance loss CsPbI photovoltaic devices can be reversed by exposing degraded samples to humidity, allowing recover even surpass initial performance. By careful characterization analysis throughout recovery process, underlying physical chemical...
Novel phenazinothiadiazoles were prepared by condensation of <italic>ortho</italic>-quinones and an alkynylated 5,6-diamino-2,1,3-4 benzothiadiazole evaluated as transport materials in thin film transistors.
We report a comprehensive study of the symmetrical 6,13-bis(triisopropylsilylethynyl)tetraazapentacene used as an electron transporting material in organic field-effect transistors deposited by spin/zone-casting.
Abstract Four π‐extended phosphoniumfluorene electrolytes (π‐PFEs) are introduced as hole‐blocking layers (HBL) in inverted architecture planar perovskite solar cells with the structure of ITO/PEDOT:PSS/MAPbI 3 /PCBM/HBL/Ag. The deep‐lying highest occupied molecular orbital energy level π‐PFEs effectively blocks holes, decreasing contact recombination. It is demonstrated that incorporation introduces a dipole moment at PCBM/Ag interface, resulting significant enhancement built‐in potential...
Lead sulfide (PbS) quantum dot (QD) photovoltaics have reached impressive efficiencies of 12%, making them particularly promising for future applications. Like many other types emerging photovoltaic devices, their environmental instability remains the Achilles heel this technology. In work, we demonstrate that degradation processes in PbS QDs which are exposed to oxygenated environments tightly related choice ligands, rather than intrinsic properties. particular, while 1,2-ethanedithiol...
Abstract Lead halide perovskites are a remarkable class of materials that have emerged over the past decade as being suitable for application in broad range devices, such solar cells, light‐emitting diodes, lasers, transistors, and memory devices. While they often solution‐processed semiconductors deposited at low temperatures, exhibit properties one would only expect from highly pure inorganic crystals grown high temperatures. This unique phenomenon has resulted fast‐paced progress toward...