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.

The combined time-resolved photoluminescence (PL) and theoretical study performed on luminescent [Mo6Br(i)8Br(a)6](2-)-based systems unambiguously shows that their NIR-luminescence is due to at least two emissive states. By quantum chemical studies, we show for the first time that important geometrical relaxations occur at the triplet states either by the outstretching of an apex away from the square plane of the Mo6 octahedron or by the elongation of one Mo-Mo bond. Experimental PL measurements demonstrate that the external environment (counter-ions, crystal packing) of the cluster has a noticeable impact on its relaxation processes. Temperature and excitation wavelength dependence of the two components of the luminescence spectra is representative of multiple competitive de-excitation processes in contradiction with Kasha's rule. Our results also demonstrate that the relaxation processes before and after emission can be tracked via fast time-resolved spectroscopy. They also show that the surroundings of the luminescent cluster unit and the excitation wavelength could be modulated for target applications.