Perovskites inside cavities – PEROCAI

Vertical microcavities in the light-mater strong coupling are intensively studied due to the interest in coherent and stimulated effects in such systems as polariton lasing and Bose Einstein condensation in the solid phase. These effects have been recently demonstrated in “classical” inorganic semiconductors and most of the physics is done at low temperature. Until now, attempts to study these physical processes with molecular materials have failed. In this draft, we propose to use organic-inorganic molecular quantum wells inside a vertical microcavity to demonstrate stimulated effects at room temperature.
The molecular quantum wells used in this study belong to the perovskite family. The tuning of their structural properties at the nanoscale can lead to unique electronic and optical properties that are typical neither of the organic nor of the inorganic component alone. The layered halide perovskite that we study form self-organized two-dimensional materials, having the characteristics of a semiconductor and exhibiting strong quantum confinement properties. Because the strong coupling regime in vertical microcavities containing perovskites has been achieved at room temperature and because of the wide tunability of its exciton perovskite material is a good candidate to realize vertical microcavities and study these polaritonic effects.

This draft is divided in two main parts:

- First, there is a lack of studies on the electronic structure and optical properties of organic-inorganic perovskites. Therefore, there is a fundamental interest to the determination of the band structure and of the electronic and excitonic properties in a quasi-ideal 2D system. Moreover, a deep understanding of the pérovskite quantum wells is needed before trying to observe stimulated effects on the polariton states built from their excitons and the photon of the cavity. Finally, organic-inorganic pérovskites are also studied for applications such as OLED [Hattori1996, Chondroudis2000] or hybrid organic-inorganic transistors [Kagan1999, Kagan2003, Mitzi2003]. A better understanding of their electronic and optical properties will also provide guidance for the optimisation of these devices.

- Secondly, new vertical microcavities with optimized perovskite and high quality factors will be built. The physics of these new polaritons is unexplored. Therefore, polariton relaxation efficiency and dynamics will be studied. Finally, experiments designed to observe stimulated effects on these polariton states will be performed.