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Cherotchenko Seminar
(or back to the Physics Seminars page)
- What? Electronic structures of CsPbBr$_{3-x}$Cl$_x$ perovskites: synthesis, experimental characterization, and DFT simulations.
- Who? Evgeniia Cherotchenko
- Where? Wulfruna building (city campus), MA202.
- When? Thu 31 October, 16:00.
- Why? Evgeniia will introduce her research.
- How? The talk is one hour and open to questions, tea & cookies will be provided.
- Chair: Anton Nalitov
Abstract: Lead halide perovskites have attracted close attention from the scientific community not only due to their remarkable photovoltaic properties, but also due to their applicability to light-emitting devices because of the high photoluminescence (PL) quantum efficiency and broadly tunable emission wavelengths of these materials. Particular attention is paid to inorganic mixed-halide CsPbBr$_{3-x}$Cl$_x$ compositions, which exhibit electroluminescence in the green and blue optical ranges and are actively used for the creation of various nanophotonic components. In my presentation I will discuss the electronic and optical properties of these materials and their possible applications. For every perovskite of certain composition, identified by quantitative XPS analysis, the band gap was derived from optical absorption, yielding a reliable nonlinear dependence, which could be useful for accurate prediction of the band gaps of related bulk mixed-halide perovskites. Furthermore, despite the variation in the perovskite anionic composition, their band gap remains direct at the G-point and no significant change in the shape of the band structure near this point occurs. The obtained results are confirmed by numerical calculations based on Density Functional Theory (DFT), showing the evolution of the crystal lattice constants as well as valence and conduction band structures.
