Ambjörn Joki, MPPHS Physics

​Title of Master thesis: Electron Phonon Coupling in Perovskites

Password: dispersion

​Abstract:
Perovskites are interesting materials due to their special optoelectronic properties. Properties already being used in photovoltaics and potentially in future light-emitters. Since perovskites exhibit strongly bound excitons, the excitonic properties, often still at room temperature, are crucial to consider. In this work a model aimed at describing the excitonic landscape in 2D and 3D has been developed including the exchange interaction giving rise to an exciton fine structure consisting of optically active and inactive exciton states the latter with lower energy. The model is further extended by inclusion of a magnetic field, necessary in experimental setups to probe the inactive states. The developed model captures the qualitative excitonic aspects of 3D perovskites but fails for the 2D case. The error is probably related to the treatment of the confined direction. Further, the exciton phonon scattering between active and inactive states is modelled. For applications this is important since high scattering rates will transfer many states from the active ones to the inactive one with lower energy, lowering the light emission. Assuming spin conservation, the phonon scattering between active and non-active states is found to be non-existing.  

​Supervisors:  Raul Perea Causin, Paul Erhart and Ermin Malic
Examiner: Paul Erhart
​Opponent: Madeleine Karlsson
Category Student project presentation
Location: Physics Soliden, university building, Origovägen 6B, Campus Johanneberg, von Bahr
Starts: 10 June, 2022, 09:00
Ends: 10 June, 2022, 10:00

Page manager Published: Mon 30 May 2022.