Highly efficient green emission Cs₄PbBr₆ quantum dots with stable water endurance

Abstract

To date, quantum dots (QDs) based on perovskite materials with high photoluminescence quantum yield (PLQY) and stability have rarely been reported. In this work, Cs4PbBr6 QDs glass ceramic with high PLQY and water stability is obtained, and the research results confirm that the strong green emission originates from the trapping of free excitons by internal Br vacancies. The rise of Br vacancies and the spontaneous growth of multi-morphology Cs4PbBr6 QDs under the influence of air humidity increase the PLQY to 89.62%. Compared with pure QDs, the Cs4PbBr6 QDs maintain high-intensity luminescence after being immersed in water for up to 150 days. In short, this paper puts forward a new, to the best of our knowledge, and valuable perspective for investigating the luminescence of Cs4PbBr6 QDs glass ceramic derived from related work.

Physics-driven discovery and bandgap engineering of hybrid perovskites

“…The use of GA ions has been reported to passivate defects in the perovskite systems, which can reduce non-radiative recombinations. 41,43,68 The steric suppression of phase segregation can stabilize the bandgap under illumination, 69 which is an indicator that the phase separation observed in the XRD results does not impact the bandgap model in a mixed GA and MA system. GA can serve as a modifying agent within the perovskite structure by inuencing phase stability and ion migration by various mechanisms.…”

Understanding the Ligand-Assisted Reprecipitation of CsPbBr3 Perovskite Nanocrystals via High Throughput Robotic Synthesis Approach

“…In fact, it has been reported that both the intact CsPbBr3 PNCs and Cs4PbBr6 NCs where CsPbBr3 PNCs are residually doped can emit green PL over 500 nm. 23,24,30,31,42,43 Therefore, the emergence of Cs-rich Cs4PbBr6 NPs is essentially not distinguishable by sole judgement from the PL peak positions. However, the colorless dispersions in the well plate suggest the phase transformation to Cs4PbBr6 NCs (Figure S2).…”