Project: TRICEPS - TRansport ImpliCations of Electron-Phonon Scattering

Prace Call: 17th
ID: 2018184411, Leader: Feliciano Giustino
Affiliation: University of Oxford, UK
Research Field: Chemical Sciences and Materials
Collaborators: Martin Schlipf University of Oxford UK , Samuel Ponce University of Oxford UK , George Volonakis University of Oxford UK , Lorenzo Paulatto Sorbonne Universite FR , Wenbin Li University of Oxford UK , Weng Hong Sio University of Oxford UK
Resource Awarded: 25 Mil. core hours on MareNostrum

Abstract

Improving the performance of optoelectronic devices can reduce the carbon footprint of society in the form of renewable energy source (photovoltaics) and more efficient light sources (LEDs) or transistors. Traditionally, optoelectronic devices are build from ultra pure crystalline semiconductors. The recent discovery of halide perovkistes offers a new route based on solution processing which delivers excellent optoelectronic properties. Despite the success of these materials, there are still fundamental open questions on the origin of their high performance. In TRICEPS, we will unravel the atomistic origin of the transport properties, and enable the engineering of more efficient materials in the future. Fundamentally, optoelectronic devices convert electric charges into light or vice versa. An important criterion limiting the efficiency of these materials is the energy loss that the electric charges experience before they emit light. In our previous PRACE project CATNIP, we revealed the fundamental mechanism responsible for energy losses immediately after photoexcitation. Recent experiments suggest that at longer time scales the heating due to the energy loss cannot be ignored. In TRICEPS, we will therefore extend our methodology to include these heating effects. Furthermore, we will expand the scope of the investigated materials to tackle their poor stability. To this end, we will employ numerical methods based on the first principles of quantum mechanics, which offer a complementary viewpoint to experiments as they do not require empirical input. Within TRICEPS, we will develop an atomistic view on how the vibrating crystal structure dissipates heat to understand on which time scale the energy losses heat the materials. Finally, we will combine the calculation of electric and thermal transport to study the out-of-equilibrium processes where any electric charges lose their energy after initial photoexcitation. Our calculations will open new routes to design novel materials, and will allow us to engage with our collaborators at Oxford to translate computational predictions into real materials. The results of this project will be disseminated in high-profile scientific journals, as well as through our group's GitHub repository that contains the calculated data and workflows to reproduce our results.