Doped Lead Halide White Phosphors for Very High Efficiency and Ultra‐High Color Rendering

Abstract

Near-UV-pumped white-light-emitting diodes with ultra-high color rendering and decreased blue-light emission is highly desirable.H owever,d iscovering as ingle-phase white light emitter with such characteristics remains challenging. Herein, we demonstrate that Mn doping as lowa s0 .027 %i n the hybrid post-perovskite type (TDMP)PbBr 4 (TDMP = trans-2,5-dimethylpiperaziniium) enables to achieve ab right pure white emission replicating the spectrum of the sunsrays. Thus,awhite phosphor exhibiting an emission with CIE coordinates (0.330, 0.365), ahigh photoluminescence quantum yield of 60 %( new recordf or white light emission of hybrid lead halides), and an ultra-high color rendering index (CRI = 96, R9 = 91.8), corresponding to the recordv alue for as ingle phase emitter was obtained. The investigation of the photoluminescence properties revealed how free excitons,s elftrapped excitons,and lowamount of Mn dopants are coupled to give rise to such pure white emission.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Zero‐Dimensional Hybrid Cd‐Based Perovskites with Broadband Bluish White‐Light Emissions

“…A best fitting to the data give Γ 0 =565.86 meV, Γ phonon =17.19 meV, Γ inhomo =157 meV for compound 1 and Γ 0 =941.51 meV, Γ phonon =67.10 meV, Γ inhomo =155.08 meV for compound 2 , respectively (Figure c and Figure d). As expected, all these fitted values are agreement with those of low‐dimensional halide perovskites with broadband emissions, such as (H 2 O)(C 6 H 8 N 3 ) 2 Pb 2 Br 10 , (2meptH 2 )PbCl x Br 4‐x , (C 4 H 14 N 2 ) 2 In 2 Br 10 , etc, which indicate the major contributions of electron‐phonon coupling to the broadening of the white‐light emissions . Hence, the broadband light emissions of compounds 1 – 2 can be ascribed to the radiative recombinations of self‐trapped excitons owing to the strong electron‐phonon coupling effect in distorted 0D crystal lattices.…”

Mn2+‐Doped Metal Halide Perovskites: Structure, Photoluminescence, and Application

“…In addition to 3D perovskites, low‐dimensional metal halide perovskites including 2D and 1D can be considered as more suitable acceptors for dopants due to their characteristic strongly bound exciton with high binding energies, which can enhance the energy transfer from host to dopants. [ 139,167–169 ] Kundu's group reported the Mn 2+ ‐doped (C 4 H 9 NH 3 ) 2 PbBr 4 perovskite by the mechanical grinding and thermal annealing, [ 168 ] and Figure a shows the crystal structure of (C 4 H 9 NH 3 ) 2 PbBr 4 :Mn 2+ . Undoped (C 4 H 9 NH 3 ) 2 PbBr 4 shows the narrow band‐edge emission.…”

Hydrogen Bonding and Broad-Band Emission in Hybrid Zinc Halide Phosphors

“…This organic molecule was previously used to synthesize 1D hybrid post-perovskite with record quantum yields of white photoluminescence among the hybrid lead halides. [11][12][13] The synthesis is carried out under hydrothermal conditions from a mixture of zinc metal, HX (X= Cl or Br) and 2,5-DMP (see experimental section in SI).…”

“…DFT and TD-DFT calculations of [ZnCl 4 ] 2-: (a) Change of electron density from the ground state to the excited state (decrease/increase of electron density in yellow/blue), (b)Optimized geometry in its ground state (green) and excited state (yellow) from TD-DFT calculations of the isolated anion, and (c) of the anion in environment of (2,5-DMP)ZnCl 4 .To confirm the role of the hydrogen bond strength on the formation of V k centers, 1 H-13 C CP-MAS NMR spectra were acquired. As one can observe on Figure 4, the NMR spectra depend on the halogen and on the organic molecule.…”