Considering the toxicity problem of lead-based perovskite quantum dots(PQDs),the lead-free Cs_(3)Bi_(2)Br_(g)PQDs has been recognized as one of the promising candidates.However,the low photoluminescence quantum yields...Considering the toxicity problem of lead-based perovskite quantum dots(PQDs),the lead-free Cs_(3)Bi_(2)Br_(g)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,w e successfully prepared Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)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)HJ(J=5/2,7/2,9/2))of Sm^(3+)ions for Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)PQDs.More importantly,compared with the undoped Cs_(3)Bi_(2)Br_(g)PQDs,the PLQYs of Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)PQDs are improved from 10.9%to 20.8%,and the anti-water stability is also obviously improved.Finally,the Sm^(3+)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.展开更多
In order to obtain a single-host-white-light phosphor, a series of Bal.8 -x-y-zSrwLi0.4xCexEuyMnzSi04 （BSLS：Ce3＋,Eu2＋, Mn2＋） powder samples were synthesized via high temperature solid-state reaction. The structu...In order to obtain a single-host-white-light phosphor, a series of Bal.8 -x-y-zSrwLi0.4xCexEuyMnzSi04 （BSLS：Ce3＋,Eu2＋, Mn2＋） powder samples were synthesized via high temperature solid-state reaction. The structure and photoluminescence properties were investigated. Under ultraviolet excitation, the emission spectra contained three bands： the 370-470 nm blue band, the 470-570 nm green band and the 570-700 nm red band, which arose from the 5d---4f transitions of Ce3＋ and Eu2＋, and the 4TI---6A1 transition of Mn2＋, respectively. The excitation spectra of the emissions of Ce3＋ and Mn2＋ ions showed the energy transfer from Ce3＋ to Mn2＋. White light emission was obtained from the tri-doped samples of appropriate doping concentration under 31 0-360 nm excitation.展开更多
基金Project supported by the National Natural Science Foundation of China(U1904178.11704202.11504131,51374132)the Program for Science&Technology Innovation Talents in Universities of Henan Province(19HASTIT019).
文摘Considering the toxicity problem of lead-based perovskite quantum dots(PQDs),the lead-free Cs_(3)Bi_(2)Br_(g)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,w e successfully prepared Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)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)HJ(J=5/2,7/2,9/2))of Sm^(3+)ions for Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)PQDs.More importantly,compared with the undoped Cs_(3)Bi_(2)Br_(g)PQDs,the PLQYs of Sm^(3+)ions doped Cs_(3)Bi_(2)Br_(g)PQDs are improved from 10.9%to 20.8%,and the anti-water stability is also obviously improved.Finally,the Sm^(3+)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.
基金Project supported by National Natural Science Foundation of China (11074245,10904139,11204292)
文摘In order to obtain a single-host-white-light phosphor, a series of Bal.8 -x-y-zSrwLi0.4xCexEuyMnzSi04 （BSLS：Ce3＋,Eu2＋, Mn2＋） powder samples were synthesized via high temperature solid-state reaction. The structure and photoluminescence properties were investigated. Under ultraviolet excitation, the emission spectra contained three bands： the 370-470 nm blue band, the 470-570 nm green band and the 570-700 nm red band, which arose from the 5d---4f transitions of Ce3＋ and Eu2＋, and the 4TI---6A1 transition of Mn2＋, respectively. The excitation spectra of the emissions of Ce3＋ and Mn2＋ ions showed the energy transfer from Ce3＋ to Mn2＋. White light emission was obtained from the tri-doped samples of appropriate doping concentration under 31 0-360 nm excitation.
