Samarium doping improves luminescence efficiency of Cs₃Bi₂Br₉ perovskite quantum dots enabling efficient white light-emitting diodes

Yongsheng Zhu¹，Jinyang Zhu²，Haizhen Song¹，Jinshu Huang¹，Zhiwen Lu¹，Gencai Pan³

1. College of Physics and Electronic Engineering,Nanyang Normal University2. State Centre for International Cooperation on Designer Low-carbon & Environmental Materials,School of Materials Science and Engineering,Zhengzhou University3. School of Physics and Electronics,Henan University

摘 要：Considering the toxicity problem of lead-based perovskite quantum dots（PQDs）,the lead-free Cs₃ Bi₂ Br₉ PQDs has been recognized as one of the promising candidates.However,the low photoluminescence quantum yields（PLQYs） hinder its practical application in optoelectronic devices.Here,we successfully prepared Sm³⁺ ions doped Cs₃ Bi₂ Br₉ PQDs with effective white light-emission by modified ligandassisted recrystallization method.The realization of white light-emission is attributed to the broadband blue emission of excitons and the red emission(⁴ G_5/2-⁶ H_J（J=5/2,7/2,9/2）) of Sm³⁺ ions for Sm³⁺ions doped CS₃ Bi₂ Br₉ PQDs.More importantly,compared with the undoped Cs₃ Bi₂ Br₉ PQDs,the PLQYs of Sm³⁺ ions doped Cs₃ Bi₂ Br₉ PQDs are improved from 10.9% to 20.8%,and the anti-water stability is also obviously improved.Finally,the Sm³⁺ ions doped PQDs based white light-emitting diodes（LEDs） with luminous efficiency of 12.6 lm/W were explored,which indicates that there is a potential prospect of lead-free PQDs in white light lighting application.

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