Global structure Optimization of Two-Dimensional Lead Halide Perovskites

10. 2. 2022 - 11:00 

CEITEC BUT, Purkyňova 123, S building, large meeting room (or online)   

 Juraj Ovčar, Division of Theoretical Physics, Ruđer Bošković Institute, Croatia  

Abstract:

Hybrid quasi-two-dimensional perovskites (Q2DPs) are a class of materials consisting of lead-halide perovskite slabs intercalated with (bi)layers of organic cations. This pronounced anisotropy leads to quantum and dielectric confinement of the charge carriers to the quasi-2D perovskite layers, giving rise to widely tunable physical properties beneficial for optoelectronic and photovoltaic applications. The tunability of the physical properties stems from the great variety of possibilities in choosing the particular chemical composition of the material. In this seminar, we present a computational method, dubbed GO-MHALP (Global Optimization by Minima Hopping Algorithm for Layered Perovskites), which intends to predict the crystal structure of Q2DPs for a given chemical composition utilizing a combined classical potential & DFT approach. We use GO-MHALP in a joint experimental and computational investigation to show that mixing iodine and bromide halides allows for the synthesis of a Q2DP with the bulky tert-butyl ammonium cation.

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