News

New paper published in New J. Phys.

CEST's paper on multiscale modeling of perovskites is published in New Journal of Physics.

Jari Järvi, Jingrui Li and Patrick Rinke have developed a multiscale model to describe the disordered structures in hybrid perovskites. This model can generate large-scale picture of these amazing materials in good agreement with reality, and allows real-time dynamical simulation of important processes such as charge transport.

Multi-scale model for the structure of hybrid perovskites: analysis of charge migration in disordered MAPbI3 structures

Jari Järvi, Jingrui Li and Patrick Rinke, New J. Phys., 20 103013 (2018) (http://iopscience.iop.org/article/10.1088/1367-2630/aae295/meta)

Multiscale model of halide perovskites

We have developed a multi-scale model for organic-inorganic hybrid perovskites (HPs) that applies quantum mechanical (QM) calculations of small HP supercell models to large coarse-grained structures. With a mixed quantum-classical hopping model, we have studied the effects of cation disorder on charge mobilities in HPs, which is a key feature to optimize their photovoltaic performance. Our multi-scale model parametrizes the interaction between neighbouring methylammonium cations (MA+) in the prototypical HP material, methylammonium lead triiodide (CH3NH3PbI3, or MAPbI3). For the charge mobility analysis with our hopping model, we solved the QM site-to-site hopping probabilities analytically and computed the nearest-neighbor electronic coupling energies from the band structure of MAPbI3 with density-functional theory. We investigated the charge mobility in various MAPbI3 supercell models of ordered and disordered MA+ cations. Our results indicate a structure-dependent mobility, in the range of 50–66 cm2V-1s-1, with the highest observed in the ordered tetragonal phase.

  • Published:
  • Updated:
Share
URL copied!

Read more news

Research group members at Karjaa medieval church in May 2020. Photo: Panu Savolainen
Research & Art Published:

Kone Foundation provides major funding for research into Finland's medieval wooden building heritage

Assistant Professor Panu Savolainen's research group receives 347 000 euros in funding.
Photo: Mika Huisman
Research & Art Published:

New Media Master's Thesis presentations / Mon 13.12.2021

Welcome to follow New Media Master’s Thesis presentations!
ConnectToBrain research. Photo: Mikko Raskinen
Cooperation, Research & Art Published:

Over €2 million awarded to the University of Helsinki and Aalto University for research identifying mechanisms of depression

A new collaborative project in neuroscience, which is being carried out by the University of Helsinki and Aalto University and which originates in the Multi-Channel Psych programme of the Wellcome Leap organisation, has received a grant of over €2 million for a period of three years.
Dominic Stead, Tenured Professors' Installation Talks
Research & Art Published:

Dominic Stead: Cities that need less transport

Organizing our cities differently can help us to reduce the need for transport and encourage more walking and cycling. This can help to reduce many of the negative environmental and social impacts of transport, says Professor Stead in his installation lecture.