Optical properties of all-inorganic perovskite nanocrystals
演讲课题:Optical properties of all-inorganic perovskite nanocrystals
演讲人:Tom Gregorkiewicz
演讲摘要:
All-inorganic cesium lead halide perovskite nanocrystals (NCs, CsPbX3 NCs, X = Cl, Br, I) attract much attention recently due to their outstanding optical properties. Here I will discuss our recent results concerning three important aspects of their micro¬scopic characteristics: (i) an explicit demonstration of a relation between NC size and shape with their bandgap, and the effective coupling between proximal NCs; (ii) simultaneous formation of insulating Cs4PbBr6nanohexagons and Cs4PbBr6/CsPbBr3 hybrid nanospheres during the synthesis of CsPbX3 NCs; and (iii) spontaneous merging of drop-casted colloid at room conditions by seamless stitching of aligned NCs [1]. The latter process is accelerated by humidity and heat treatments, while arrested with electron beam irradiation. Further, I will present some detailed information on carrier dynamics in perovskite NCs, their water-resistant encapsulation, and on energy exchange within their ensembles obtained by using high-resolution induced absorption and emission spectroscopies. Finally, I will also discuss the most recent results concerning successful observation of efficient carrier multiplication in CsPbI3 NCs with bandgap energy around 1.8 eV [2]. [1] L. Gomez et al. ACS Appl. Mater. Interfaces (2018) [2] Ch. de Weerd et al. Nature Communications (2018)