A5076458063- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Perovskite Materials and Applications
- Quantum Dots Synthesis And Properties
- Organic Electronics and Photovoltaics
- Solid-state spectroscopy and crystallography
- Conducting polymers and applications
- Chalcogenide Semiconductor Thin Films
- Copper-based nanomaterials and applications
- Organic and Molecular Conductors Research
- High-Temperature Coating Behaviors
- Luminescence Properties of Advanced Materials
- ZnO doping and properties
- Organic Light-Emitting Diodes Research
- 2D Materials and Applications
- Electronic and Structural Properties of Oxides
- Advanced NMR Techniques and Applications
University of Bayreuth
2019-2025
Bavarian Polymer Institute
2019-2021
In this report, we investigate the binding properties of Lewis acid tris(pentafluorophenyl)borane with a base semiconducting polymer, PFPT, and subsequent mechanism band gap reduction. Experiments quantum chemical calculations confirm that formation adduct is energetically favorable (ΔG° < −0.2 eV), preferential at pyridyl nitrogen in polymer backbone over other sites. Upon formation, ultraviolet photoelectron spectroscopy indicates only slight decrease HOMO energy, implying larger reduction...
We present three new hybrid layered lead(II) bromide perovskites of generic composition A2PbBr4 or AA'PbBr4 that exhibit distinct structure types. [TzH]2PbBr4 ([TzH+] = 1,2,4-triazolium) adopts a (001)-oriented layer and [AaH]2PbBr4, ([AaH+] acetamidinium) (110)-oriented type, whereas [ImH][TzH]PbBr4, ([ImH+] imidazolium) rare with enhanced corrugation (i.e., 3 × type). The crystal structures each are discussed in terms the differing nature templating molecular species. Photoluminescent...
In recent years, record efficiencies of halide perovskite-based devices have been achieved by processing high-quality thin films, where small morphology differences seem to be relevant for optimized optoelectronic functionality. However, a detailed understanding on how morphological changes in perovskite films affect their structural and properties is still missing. Here, we investigate the influence (i.e., increased grain size crystallographic orientation), which are induced hot-pressing...
Abstract The solution‐based fabrication of reproducible, high‐quality lead iodide perovskite films demands a detailed understanding the crystallization dynamics, which is mainly determined by precursor solution and its processing conditions. A systematic in situ study conducted during critical phase before nucleation to elucidate formation dynamics films. Using ultraviolet (UV) absorption spectroscopy spin coating allows track evolution iodoplumbate complexes present solution. It found that...
This work presents a novel perovskite thin film fabrication approach based on an optical in situ spectroscopy setup and live closed-loop feedback system to improve the reproducibility of layer properties independent external parameters.
The influence of an ionic liquid (IL) on the film formation perovskite MAPbI 3 is studied by multimodal in situ optical spectroscopy, where IL found to impact evolution precursor states and reduce growth rate perovskite.
Abstract The powder aerosol deposition (PAD) method is becoming increasingly important as an energetically advantageous coating compared to classic ceramic technologies. However, due the process‐related lattice deformation, coatings often exhibit reduced functional properties in as‐deposited state. A thermal posttreatment at temperatures well below sintering temperature can significantly reduce deformation and stress within film restore close sintered bulk samples. In this work, optothermal...
Preparing halide perovskite films by solvent‐free, powder‐based processing approaches currently attracts more and attention. However, working solar cells employing dry, thin films, have not been demonstrated so far. Herein, are presented where the absorber layer is prepared transferring readily synthesized powders into a compact film using fully dry‐powder‐processing concept. Compact deposited via an optimized powder aerosol deposition (PAD) process. Pressing at 120 °C further improves...
Abstract Copper salts are a popular choice as p ‐dopants for organic semiconductors, particularly in N 2 ,N 2′ 7 7′ ‐octakis(4‐methoxyphenyl)‐9,9′‐spirobi[9H‐fluoren]‐2,2′,7,7′‐tetramine (Spiro‐MeOTAD) hole transport material solar cells. While being exceptionally effective, no scientific consensus about their doping mechanism has been established so far. This study describes the thermodynamic equilibria of involved species copper(II) bis(trifluoromethanesulfonyl)imide (Cu(TFSI) ) doped,...