A5031896822- Perovskite Materials and Applications
- Conducting polymers and applications
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Solid-state spectroscopy and crystallography
- Optical properties and cooling technologies in crystalline materials
- Organic Light-Emitting Diodes Research
- Polyoxometalates: Synthesis and Applications
- Catalysis and Oxidation Reactions
- Mesoporous Materials and Catalysis
- Thermal Expansion and Ionic Conductivity
- ZnO doping and properties
- Electronic and Structural Properties of Oxides
- Crystal Structures and Properties
- Semiconductor Quantum Structures and Devices
- Advanced Semiconductor Detectors and Materials
- Organic Electronics and Photovoltaics
- Organic and Molecular Conductors Research
- Inorganic Chemistry and Materials
- Microbial Fuel Cells and Bioremediation
- Advanced Thermoelectric Materials and Devices
- Topological Materials and Phenomena
- Advanced ceramic materials synthesis
- 2D Materials and Applications
- Luminescence and Fluorescent Materials
Vrije Universiteit Amsterdam
2024-2025
Institute for Atomic and Molecular Physics
2019-2025
Utrecht University
2022-2025
University of Amsterdam
2017-2019
GGD Amsterdam
2019
Solar cells based on organic-inorganic metal halide perovskites show efficiencies close to highly-optimized silicon solar cells. However, ion migration in the perovskite films leads device degradation and impedes large scale commercial applications. We use transient ion-drift measurements quantify activation energy, diffusion coefficient, concentration of mobile ions methylammonium lead triiodide (MAPbI3) cells, find that their properties change tetragonal-to-orthorhombic phase transition...
Solar cells based on metal halide perovskites often show excellent efficiency but poor stability. This degradation of perovskite devices has been associated with the migration mobile ions. MAPbBr3 materials are significantly more stable under ambient conditions than MAPbI3 materials. In this work, we use transient ion drift to quantify key characteristics in solar cells. We then proceed compare them those find that MAPbBr3, bromide is main process at play and contrary case MAPbI3, there no...
The bandgap tunability of mixed-halide perovskites makes them promising candidates for light-emitting diodes and tandem solar cells. However, illuminating results in the formation segregated phases enriched a single halide. This segregation occurs through ion migration, which is also observed single-halide compositions, whose control thus essential to enhance lifetime stability. Using pressure-dependent transient absorption spectroscopy, we find that rates both iodide- bromide-rich MAPb(Br x...
Growing large, oriented grains of perovskite often leads to efficient devices, but it is unclear if properties the are responsible for efficiency. Domains observed in SEM commonly misidentified with crystallographic grains, images do not provide diffraction information. We study methylammoinium lead iodide (MAPbI3) films fabricated via flash infrared annealing (FIRA) and conventional antisolvent (AS) method by measuring grain size orientation using electron back-scattered (EBSD) studying how...
Ion migration in perovskite layers can significantly reduce the long-term stability of devices. While composition engineering has proven an interesting tool to mitigate ion migration, many optoelectronic devices require a specific bandgap and thus composition. Here, we look at effect grain size migration. We find that MAPbBr3 solar cells prepared with sizes varying from 2 11 μm activation energy for bromide increases 0.17 0.28 eV. Moreover, observe appearance second pathway largest size,...
Organic semiconductors exhibit properties of individual molecules and extended crystals simultaneously. The strongly bound excitons they host are typically described in the molecular limit, but can delocalize over many molecules, raising question how important crystalline nature is. Using accurate Green's function based methods for electronic structure nonperturbative finite difference exciton-vibration coupling, we describe exciton interactions with crystal degrees freedom concurrently. We...
Layered Dion-Jacobson (DJ) and Ruddlesden-Popper (RP) hybrid perovskites are promising materials for optoelectronic applications due to their modular structure. To fully exploit functionality, mechanical stimuli can be used control properties without changing the composition. However, responsiveness of these systems pressure compatible with practical (<1 GPa) remains unexploited. Hydrostatic is investigate structure-property relationships in representative iodide bromide DJ RP 2D based on...
Recent work of ten different groups shows that the application zinc-halides in lead perovskite materials results a contraction d-space, stronger interaction with organic cation, improved crystallization larger crystal domains, Goldschmidt factor closer to unity, smoother and denser thin films an even distribution Zn(II) (at Pb(II) sites) throughout material. These combined effects may to: (1) substantially higher stability (even at ambient or high humidity conditions); (2) enhanced...
Abstract Patterning materials with different properties in a single film is fundamental challenge and essential for the development of next‐generation (opto)electronic functional components. This work introduces concept ion exchange lithography demonstrates spatially controlled patterning electrically insulating films semiconductors tunable optoelectronic properties. In lithography, reactive nanoparticle “canvas” locally converted by printing “inks.” To demonstrate proof principle, canvas...
Abstract Nanoribbons, nanometre-wide strips of a two-dimensional material, are unique system in condensed matter. They combine the exotic electronic structures low-dimensional materials with an enhanced number exposed edges, where phenomena including ultralong spin coherence times 1,2 , quantum confinement 3 and topologically protected states 4,5 can emerge. An exciting prospect for this material concept is potential both tunable semiconducting structure magnetism along nanoribbon edge, key...
Mechanochemical ball mill synthesis is an emerging method for producing complex materials, including alloyed halide elpasolite semiconductors. This solvent-free offers precise control over chemical composition, enabling fine-tuning of optical and mechanical properties. However, the formation mechanism elpasolites remains unclear. In this work, we elucidate crystallization kinetics mechanochemical Cs2AgBi0.5M0.5Br6 [M = Sb3+, In3+, or Fe3+] using in situ synchrotron X-Ray diffraction...
We present a one-step method to produce air-stable, large-grain mixed cationic lead perovskite films and powders under ambient conditions. The introduction of 2.5 % Zn(II), confirmed by X-ray diffraction (XRD), results in stable thin which show the same absorption crystal structure after 2 weeks storage Next prolonged stability, Zn(II) affects photophysical properties, reducing bulk defect density, enhancing photoluminescence (PL), extending charge carrier lifetime. Furthermore,...
Halide alloying in metal halide perovskites is a useful tool for optoelectronic applications requiring specific bandgap. However, mixed-halide show ion migration the perovskite layer, leading to phase segregation and reducing long-term stability of devices. Here, we study process methylammonium-based with varying ratios bromide iodide. We find that two separate processes, contrast pure-phase perovskites, which only unique component. Compared pure-halide these processes have lower activation...
Mixing iodide and bromide in halide perovskite semiconductors is an effective strategy to tune their bandgap, therefore mixed-halide perovskites hold great promise for color-tunable LEDs tandem solar cells. However, the bandgap of unstable under (sun-)light, since halides segregate into domains different bandgaps. Using pressure-dependent ultrafast transient absorption spectroscopy, we show that high external pressure increases range thermodynamically stable mixing ratios. Chemical pressure,...
Understanding and controlling the crystallization of organic–inorganic perovskite materials is important for their function in optoelectronic applications. This control particularly delicate scalable single-step thermal annealing methods. In this work, mechanisms flash infrared-annealed films, grown on substrates with lithographically patterned Au nucleation seeds, are investigated. The patterning enables situ observation to study kinetics precise domain growth, while retaining...
Abstract Halide double perovskite semiconductors such as Cs 2 AgBiBr 6 are widely investigated a more stable, less toxic alternative to lead‐halide perovskites in light conversion applications including photovoltaics and photoredox catalysis. However, the relatively large indirect bandgap of limits efficient sunlight absorption. Here, it is shown that controlled replacement Bi 3+ with Fe via mechanochemical synthesis results remarkable tunable absorption onset between 2.1 ≈1 eV....
In this work, we employ vacuum deposited Au nanoparticles (∼4 nm) to control the defect density on surface of hydrothermally synthesized ZnO nanorod arrays (ZnO-NR), which are interest for electron-transport layers in perovskite solar cells. Using a combination photoluminescence spectroscopy, X-ray photoelectron and ultraviolet show that particles reduce presence defects ZnO-NR. We discuss terms trap filling due band bending at ZnO-NR surface. As proof-of-concept, apply Au-decorated as...
Lead-halide perovskites offer excellent properties for lighting and display applications. Nanopatterning perovskite films could enable perovskite-based devices with designer properties, increasing their performance adding novel functionalities. We demonstrate the potential of nanopatterning achieving light emission a film into specific angular range by introducing periodic sol-gel structures between injection emissive layer using substrate conformal imprint lithography (SCIL). Structural...
Halide perovskites and elpasolites are key for optoelectronic applications due to their exceptional performance adaptability. However, understanding crucial elastic properties synthesis device operation remains limited. We performed temperature- pressure-dependent synchrotron-based powder X-ray diffraction at low pressures (ambient 0.06 GPa) investigate in ambient-pressure crystal structure. found common trends bulk modulus thermal expansivity, with an increased halide ionic radius (Cl Br I)...
Hot-carrier cooling (HCC) in metal halide perovskites above the Mott transition is significantly slower than conventional semiconductors. This effect commonly attributed to a hot-phonon bottleneck, but influence of lattice properties on HCC behavior poorly understood. Using pressure-dependent transient absorption spectroscopy, we find that at an excitation density below transition, pressure does not affect HCC. On contrary, methylammonium lead iodide around 2–3 times faster 0.3 GPa ambient...
It is thought that growing large, oriented grains of perovskite can lead to more efficient devices. We study MAPbI3 films fabricated via Flash Infrared Annealing (FIRA) consisting highly oriented, large grains. Domains observed in the SEM are often misidentified with crystallographic grains, but images don't provide diffraction information. measure grain size, crystal structure and orientation using Electron Back-Scattered Diffraction (EBSD) we how these affect optoelectronic properties as...