High performance single-mode vertical cavity surface emitting lasers based on CsPbBr3 nanocrystals with simplified processing

Abstract

• A simple ligand-assisted reprecipitation strategy is developed for applications in CsPbBr 3 PNCs-based VCSELs. • The fabricated VCSELs exhibit excellent single-mode lasing without mode competition. • Low lasing threshold (8 μJ/cm 2 ), high Q (~1425) and SE coupling factor (~0.24) are achieved. • The ultrafast decay of ~10 ps indicate a high modulation bandwidth (~GHz) of the VCSELs. Perovskite nanocrystals (PNCs) have emerged as highly promising optical gain materials for laser applications. Despite the recent surge of reports on their lasing performance, it remains a challenge to achieve PNCs-based single-mode vertical cavity surface emitting lasers (VCSELs) because of their inhomogeneous gain saturation. Here, we successfully demonstrate high performance single-mode VCSELs using CsPbBr 3 PNCs that were synthesized via a facile ligand-assisted reprecipitation strategy. The optical gain medium with wide crystal size range was fabricated, and the dense assembly of each individual PNCs was expected to offer a homogeneous optical continuum to reduce gain saturation inhomogeneity. The fabricated VCSELs exhibit excellent single-mode lasing at ~541 nm without mode hopping and high spontaneous emission coupling factor of ~0.24, which is one order of magnitude higher than those of nitride-based VCSELs. Through streak camera direct observations, the stimulated emission of the laser device exhibits an ultrafast decay of ~10 ps, and the electron hole plasma (EHP) mechanism is considered responsible for stimulated emission in the VCSELs. This work paves the way toward next-generation high performance PNC-based single-mode laser devices with reduced fabrication cost for practical application.