Atomistic Simulations of Nucleation of Lead Halide Perovskites
Paramvir Ahlawat a, Michele Parrinello b, Ursula Rothlisberger a
a Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, Switzerland
b ETH, Zurich, Switzerland
Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV19)
Roma, Italy, 2019 May 12th - 15th
Organizers: Prashant Kamat, Filippo De Angelis and Aldo Di Carlo
Oral, Paramvir Ahlawat, presentation 175
Publication date: 11th February 2019

Control over morphology plays a very important role in obtaining high efficiencies of lead halide perovskites solar cells. Nucleation and crystal growth processes dictate the evolution of morphology. To probe the atomic level mechanism of nucleation, experimental methods are limited by the length and time scales. Therefore, we perform the molecular dynamics (MD) simulations of homogeneous and heterogeneous nucleation of lead halide perovskites. However, nucleation from solution is a typical example of a rare event process and therefore it poses a very big challenge to perform the MD simulations. Here, we use the enhanced sampling technique of Metadynamics to overcome these challenges. Metadynamics employs a bias potential which is constructed from a few collective coordinates of the system. In this study, we introduce new generalized reaction coordinates to form perovskite crystals from MD simulations. From our simulations[1], we layout the individual stages of the nucleation of lead halide perovksites. We find that the monovalent cations plays a very important role to initiate the nucleation process. We also identify the relevant intermediate metastable structures formed during nucleation. Our simulations of nucleation of mixed-cation systems reveal the in-depth details of the effects of different cations on the evolution of morphology.

© Fundació Scito
We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info