Thermal quenching of luminescence in hybrid organic-inorganic perovskites. - Neutron scattering studies of the effect of organic cation dynamics

Hybrid organic-inorganic perovskites (HOIPs) are currently accumulating considerable interest because of their photoelectric and luminescent properties and concomitant promise for use in solar cells and light emitting diodes.

One common property, linking the performance of these devices is a high radiative efficiency, but non-radiative losses due to thermal quenching of luminescence, in which the radiative efficiency decreases with increasing temperature, hinder the application of HOIPs in practical devices.

The development of new, better performing materials depends on a better understanding of the underlying mechanisms causing this unwanted behavior. Recent work points toward the importance of organic cation dynamics.

However, previous studies in relation to organic cation dynamics is limited to only very few HOIPs, wherefore there is a clear gap of fundamental understanding pertaining to the general behavior of organic cation dynamics in these materials.

My proposal is to provide a crucial contribution to this problem by unravelling the nature of organic cation dynamics in a set of prototypical HOIP materials and, especially, how it is linked to thermal quenching of luminescence. The primary tools to this end involve the use of advanced neutron scattering and optical characterization techniques.

The project is intended for the period 2022-01-01 - 2025-12-31 and is based on the collaboration between myself, one new doctoral student, and colleagues in Italy and the U.K.