Carrier, spin and optical propagation properties of CsPbBr3 hexagonal nanocrystals

The shape of nanocrystals can effectively adjust their photo-physical properties, which becomes a route to improve the nanocrystal-based semiconductor device. Herein, we further dig the photo-physical properties of CsPbBr3 hexagonal nanocrystals (HNCs), in which CsPbBr3 cubic nanocrystals (CNCs) serves as a reference. It is found that the activity of carrier in CsPbBr3 HNCs is higher than that of CsPbBr3 CNCs, owing to the slow energy dissipation path related to the phonon energy, which slows down the carrier temperature cooling process and accelerate the carrier recombination behavior simultaneously. Moreover, the spin flip process may occur in the CsPbBr3 HNCs, whose lifetime is longer than that of CsPbBr3 CNCs owing to the weakening of phonon scattering of Elliott-Yafet mechanism. In addition, the photoluminescence test of CsPbBr3 HNCs in optical fiber microcavity shows that its light wave-guiding performance is determined by the self-absorption effect and the conventional light wave-guiding effect, which are both super to those of CsPbBr3 CNCs, benefiting from its high PL quantum yield. Our research suggests that the CsPbBr3 HNCs exhibits a huge potential in the field of optoelectronics, spintronics and photo-communication.