SCL Seminar by Nenad Vukmirovic

SCL seminar of the Center for the Study of Complex Systems, will be held on Thursday, 19 April 2018 at 14:00 in the library reading room “Dr. Dragan Popović" of the Institute of Physics Belgrade. The talk entitled

"Effects of thermal disorder on electronic properties of hybrid halide perovskites"

will be given by Dr. Nenad Vukmirović (Scientific Computing Laboratory, Center for the Study of Complex Systems, Institute of Physics Belgrade).

Abstract of the talk:

Hybrid organic-inorganic halide perovskite materials have attracted enormous attention in last several years due to their outstanding optoelectronic properties. In particular, these materials can be used as low-cost active materials in solar cells [1, 2] with power conversion efficiencies larger than 20%. In the first part of the talk, we will give a brief overview of current understanding of properties of these materials. In the second part, we will present our results aimed at understanding the role of organic group and corresponding effects of thermal disorder in halide perovskite materials [3]. These effects were investigated using ab-initio molecular dynamics simulations. It was generally found that band gap variations due to effects of thermal disorder are the largest in materials with the smallest lattice constant. The factors that may lead to departure from this trend include the degree of rotational and translational motion of organic cation and the strength of its dipole. It was also found that the contribution of flexible organic part to band gap variations is considerably smaller than the contribution of inorganic part of the material.

[1] M. M. Lee et al, Science 338, 643 (2012).
[2] M. Liu et al, Nature 501, 395 (2013).
[3] M. Mladenović and N. Vukmirović, submitted (2018).