Publications by authors named "A S Vasenko"
Hybrid lead halide perovskites are promising materials for photovoltaic applications due to their exceptional optoelectronic properties. Here, we investigate the impact of Schottky defects─specifically PbI(V) and CHNHI (V) vacancies─on nonradiative recombination in CHNHPbI using time-dependent density functional theory and nonadiabatic (NA) molecular dynamics. Our results reveal that Schottky defects do not alter the fundamental bandgap or introduce trap states but instead distort the surrounding lattice, localizing the hole distribution.
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- Metal halide perovskites (MHPs) are popular for their low cost and performance, aided by their unique defect dynamics.
- Research focused on how defects like grain boundaries and lead interstitials create new chemical species that destabilize material properties, preventing recovery to their original structure.
- Long-lasting defects at grain boundaries negatively affect charge mobility and lifetime, emphasizing the need for effective strategies to manage these defects for improved performance.
Article Synopsis
- Metal halide perovskites are advanced materials known for their defect tolerance in carrier recombination, but they face stability issues due to weak lattice interactions leading to ion migration.
- A study using molecular dynamics and machine learning models shows that ion migration primarily happens at grain boundaries, with Br atoms being the main ones that diffuse after a brief structural change in the grain boundary.
- Increasing temperature enhances ion migration, and stabilizing the grain boundary by doping or annealing can reduce this migration, offering insights into the material's behavior and stability.
Nickel-rich layered cathode materials, particularly LiNiMnCoO (NCM811), have garnered significant attention due to their high energy density and impressive electrochemical performance. However, their cycling stability is compromised at elevated voltages, primarily due to structural instability and interfacial degradation. In this study, lithium difluoro(oxalato)borate (LiDFOB) is introduced into a commercial electrolyte based on lithium hexafluorophosphate (LiPF) to elucidate the structural and interfacial changes occurring in NCM811 at a high cut-off voltage of 4.
View Article and Find Full Text PDFWater treatment methods based on cold plasma discharge in cavitating liquid have been actively developing in recent years. However, some conditions, such as the conductivity of the medium, can limit the possibility of plasma ignition. The authors proposed a new method for activating an electric discharge in a cavitating liquid environment based on the use of an external corona discharge electrode in the plasma reactor.
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