Using a confocal PL microscope to correlate the PL and structural properties of 2D-layered perovskites crystals and thin films

International audienceOver the past few years, hybrid organic perovskites (HOP) were found to be remarkable semiconductors with outstanding optoelectronics properties. These materials are very versatile, as their bandgap and the carrier confinement can be easily tuned chemically. Many studies have focused on 3D perovskites, that tend to be good absorbing materials for thin films photovoltaic devices. Alternatively, another class of perovskites, called 2D perovskites, is getting more attention. These 2D HOP have a natural quantum well structure and a high dielectric excitonic confinement. Nevertheless, many of the fundamental photophysics properties of these 2d HOP remain to be understood. In this presentation, we will study the photoluminescence properties of 2D perovskites based on phenylethylammonium (C6H5C2H4NH3)2PbI4 and their 2d/3d derivatives (including a proportion of methylammonium). A new method will be presented to grow large grains films as well as single crystals with large aspect ratios and low roughness [1]. These single crystals have a low proportion of defects and will be then used to unveil some of the intrinsic properties of these perovskites. In particular a cryogenic confocal study will be presented, to finely probe the optoelectronic properties (excitons/phonons, …) and the presence of defects in the produced samples