Symposium 1

Structure and dynamics of halide perovskites

Chair: Linn Leppert

Symposium 2

Optoelectronic properties of halide perovskites from DFT and beyond

Chair: Giacomo Giorgi

The Online Confernece on Theory and Computation of Halide Perovskites (ComPer) took place fro September the 8^th to September the 9^th 2020.

Contents

     Bulk Hybrid Organic-Inorganic Halide Perovskites (OIHPs) with stoichiometry ABX₃ (A=organic cation; B=Pb²⁺, Sn²⁺; X=halide) have revolutionized the field of low-cost photovoltaics, with power conversion efficiencies exceeding 25%. Their success is due to unique features such as high absorption coefficients, high compatibility with solution-based processing, optimal gaps for single-junction solar devices, and the very long diffusion length of the charge carriers. To date, moisture and heat-mediated degradation of OIHP-based devices still stand in the way of device mass production. However, the use of pure inorganic and 2D OIHPs, in which the short-chain, highly hydrophilic, organic A site cation is replaced by inorganic (Cs, to form both single- or double-perovskites, i.e. CsBX3 and Cs2B’B’’X6) and long-chain hydrophobic ions, respectively, has been shown to greatly reduce the degradability of the final devices.

     Theory and computation are playing a vital role in expanding our understanding of the properties behind the success of these complex and diverse materials. Advances in machine learning algorithms and computational power in the last years have opened the way towards systematically screening millions of materials for favorable optoelectronic properties. On the other hand, highly accurate methods such as Green’s function-based many-body perturbation theory are allowing to calculate the properties of quasiparticles, such as excitons and polarons, while density functional theory (DFT) and force-field based molecular dynamics are used to understand the structural stability and dynamics of halide perovskites.

Topics

Main topics will include (but are not restricted to):

1. High-throughput and machine learning
2. Material discovery
3. Lead-free halide perovskites
4. Quasiparticles (excitons, polarons, etc) from DFT and beyond
5. Structural dynamics and (in)stability of halide perovskites.
6. Defect physics
7. Dimensionally reduced systems