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- - 6 2a) 1605945 NC 3 PbBr 4 matrix, 1a, were 6 However, However, (1 of 6) we set out www.advmat.de PbBr 4 lattice spacing lattice [24–26] 6 lattice constants; [28–30] 3 compound lattice compound 6 and CsBr precursors. PbBr 2 4 compound could pro- 6 PbBr 4 [12,27] (Supporting Information). (Supporting 6 PbBr 4 NC inside a Cs NCs can align simultaneously 3 3 PbBr 4 NCs, potentially passivating their passivating potentially NCs, 3 wileyonlinelibrary.com Core–shell structures have evolved Core–shell structures We hypothesized that passivation by We NCs (green-emitting materials), the ter (space group: 167) is shown in red in 3 achieving this heterostructuring in halide achieving this heterostructuring - perovskite NCs has so far proven diffi cult due to intermixing of halide anions between the core and the shell, leading mixed-halide of formation the to instead perovskite NCs. as a solution to this problem in conven- as a solution to this such as II-VI, IV-VI, tional nanomaterials, dots. and III-V quantum endotaxy, with the same chemical ele- chemical same the with endotaxy, crystal structure, ments but in a different could bypass halide intermixing between - the core and the shell. Inspired by the suc 6 PbBr 4 , it is unsurprising that Cs , it is unsurprising that 6 perovskite compound and hexagonal-phase Cs perovskite compound and hexagonal-phase 3 PbBr 4 To determine whether the Cs determine To The synthesis (Experimental Section and Figure An axis system representing the unit vectors of hexag- studied. From the ternary phase diagram, both cubic-phase both diagram, phase ternary the From studied. CsPbBr shown in Figure nary phase diagram of Cs, Pb, and Br, surfaces, the matching of lattice constants was explored, surfaces, the matching of lattice constants two the of directions crystallographic main the allowing while space. Computation- materials to rotate and translate freely in ally it was found that CsPbBr ovskite NC in the matrix is visualized. This alignment between cubic NCs and a geometrically anisotropic hexagonal matrix is the intricate crystalline structure of considerable interest. With of Cs with enhanced passivation of the surfaces and with practically per 1c–, alignment of a cubic no strain on the NC. In Figure fall on the same line connecting the PbBr could match a multiple of the cubic CsPbBr This match satisfies a CsPbBr however, it is fortuitous that this lattice matching can be satis- however, fied along all three dimensions simultaneously. The 1a). was informed by the ternary phase diagram (Figure cessful fabrication and synthesis of endotaxial systems among cessful fabrication and synthesis of endotaxial crystal structures, two completely different along all three dimensions of the Cs the of dimensions three all along vide endotaxy to CsPbBr to endotaxy vide to investigate the potential for endotaxy with perovskite NCs. to investigate the potential for endotaxy on CsPbBr Focusing aligns with the lattice of Cs Figure 1b. The intersecting axis system shows the rotation at 1b. The intersecting axis system shows the rotation Figure which the {100} lattice planes of a cubic-phase CsPbBr (Figure 1b–e and the Supporting Information). 1b–e and the Supporting (Figure onal phase Cs

[2,3] [4–10] perovs- 3 CsPbBr [19,20] 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim KGaA, & Co. GmbH 2017 WILEY-VCH Verlag © [22,23] Development of bright, low-cost, green Development of bright, low-cost, green [1] indicating that further improvements are [11–18] . 3 NCs have reached a 90% photoluminescence NCs have reached a 90% photoluminescence ) microcrystals, reaching a PLQY of 90%. Theoretical mode- ) microcrystals, reaching a PLQY of 90%. 3 [21] 6 crystal structure—where the A and B cations cations crystal structure—where the A and B ) embedded in robust and air-stable rhombic prism hexabro- ) embedded in robust and air-stable rhombic 3 3 PbBr 4 2017, 1605945

Polymer encapsulation of NCs has led to moderate encapsulation Polymer luminescence quantum yield (PLQY) in solution; however, maintaining yield (PLQY) in solution; however, luminescence quantum [21]

Mater. Translating the high performance of perovskite NCs into NCs perovskite of performance the high Translating color converters is therefore an active area of research. color converters is therefore an active Metal halide perovskite semiconductors have emerged as a have emerged as a halide perovskite semiconductors Metal light emitters. promising material for solution-processed an ABX With are bound to an X anion—perovskites offer wide tunability wide tunability offer are bound to an X anion—perovskites composition. their elemental altering by bandgap their of further offer nanocrystals (NCs) perovskite Furthermore, In the green spectral advantages over their bulk counterparts. region, CsPbBr required to fill the elusive green gap. One of the main hurdles main the of One gap. green elusive the fill to required with perovskite NC films is a decrease in PLQY due to agglom- eration of the NCs and subsequent loss of quantum confine- ment. solid films is an ongoing area of research. - lighting that an effi It is of urgent importance to solid-state known as the cient green-light emitter (a spectral region is found. gap”) “green improvements, but it remains an unsolved problem to achieve high PLQY in the solid state. Adv. www.advancedsciencenews.com quantum yield (PLQY) in solution, compared to sub-1% PLQY PLQY sub-1% to compared solution, in (PLQY) yield quantum for bulk CsPbBr kite NC films have so far only attained a maximum reported PLQY of 18%, Perovskite nanocrystals (NCs) have attracted attention due to their high (NCs) have attracted attention due Perovskite nanocrystals photo­ high emission efficiency in the solid state remains a challenge. This study in the solid state remains a challenge. high emission efficiency perovskite synthesis of efficient green-emitting presents a solution-phase NCs (CsPbBr State Crystalline Matrix Crystalline State Jain, Ankit Grant Walters, Voznyy, Quintero-Bermudez, Oleksandr Li Na , Rafael and Edward H. Sargent* Xueli , Zhenyu , Fan, James Zhangming Highly Emissive Green Perovskite Nanocrystals in a Solid in a Nanocrystals Perovskite Green Emissive Highly mide (Cs ling and experimental characterization suggest that lattice matching between ling and experimental characterization passivation, while spatial the NCs and the matrix contribute to improved of the NCs. In addition, dispersing confinement enhances the radiative rate which explains their high PLQY. the NCs in a matrix prevents agglomeration, DOI: 10.1002/adma.201605945 Dr. L. N. Quan, R. Quintero-Bermudez, Dr. O. Voznyy, O. Voznyy, L. N. Quan, R. Quintero-Bermudez, Dr. Dr. Z. Yang, X. Zheng, Dr. A. Jain, J. Z. Fan, Dr. G. Walters, Prof. E. H. Sargent Engineering Department of Electrical and Computer University of Toronto Ontario M5S 1A4, Canada 35 St George Street, Toronto, E-mail: [email protected] Communication 1605945 Figure 2. luminescence emittedand(c)PLQY ofmaterialsresultingfromdifferentratiosCsBrandPbBr gram of Cs, Br, and Pb, highlighting the path between precursors CsBr and PbBr Figure 1. shown in(b). perovskite inclusioninthematrix.d,e)Two differentcutsalongplanesofcubicperovskite(direction-guidedarrowcolorsareconsistentwiththose matches withthematrix.c)Cutalong(001)planeofsystem,matrixatomsreducedinsizeordertofacilitatetheobservation www.advmat.de (2 of6) Synthesis ofperovskiteCsPbBr Theoretical modelofalatticematchedcubic-phaseCsPbBr wileyonlinelibrary.com 3 -in-Cs 4 PbBr 6 microcrystalsmanifestinghighPLQY. a)Graphicalrepresentation ofthesynthesis.b)Photo­ © 2017WILEY-VCHVerlag GmbH &Co. KGaA,Weinheim 3 perovskiteNCinahexagonal-phaseCs 2 . b) Unit cell of Cs 2 . 4 PbBr 6 with axes along which cubic perovskite 4 PbBr www.advancedsciencenews.com 6 matrix.a)Ternary phasedia- Adv. Mater. 2017, 1605945 Communication - 3 1605945 (3 of 6) www.advmat.de a. The forma- 3 compound as a compound as a 6 PbBr [22] 4 wileyonlinelibrary.com ratio of 8—a significant advance over the 2 was increased. This is consistent with the NCs 2 A red-shift in photoluminescence (PL) wavelength of the in photoluminescence A red-shift Scanning electron microscopy (SEM) images of the Scanning electron microscopy (SEM) images of the composite material, from 510 to 520 nm, was found as the ratio of CsBr/PbBr resulting microcrystals are shown in Figure tion of rhombic prisms agrees with Cs matrix. Powder X-ray diffraction (XRD) (Figure 3b) confirms 3b) confirms (XRD) (Figure diffraction X-ray matrix. Powder the coexistence of perovskite and hexabromide compounds size dependent bandgap; a result of quantum confinement - 2b). The PLQY also varied with precursor concentra (Figure the PLQY reached a maximum of 2c); whereby, tion (Figures 92% at a CsBr/PbBr previous maximum (61%), which was achieved with polyhedral oligomeric silsesquioxane encapsulation. O O 2 2 , with 3 O-DMSO 2 ) of 1 leads 2 precursors can , and protic H 2 2 and CsPbBr 6 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim KGaA, & Co. GmbH 2017 WILEY-VCH Verlag PbBr © 4 crystal. c) Processed ICP-AES data showing the ratio of the compounds. d) Theoretical model for the material with crystal. c) Processed ICP-AES data showing the ratio of the compounds. 6 PbBr 4 -in-Cs crystal, color-coded to identify the compounds. Peaks without color-coding are peaks where both phases overlap. crystal, color-coded to identify the compounds. Peaks without color-coding are peaks where both 3 6 PbBr 4 microcrystals, along with some unused precursors 3 crystal, with an inset showing fast Fourier transform (FFT) of a HRTEM image. f) crystal, with an inset showing fast Fourier Selected area electrond diffraction (SAED) pattern of a 6 Identification and characterization of a hybrid material compound. a) SEM image of the perovskite-in-hexabromide compound. b) XRD Identification and characterization of a hybrid material compound. a) SEM image of the perovskite-in-hexabromide 2017, 1605945 -in-Cs 3 and CsBr in polar solvents, aprotic dimethyl sulfoxide PbBr 2 4 Mater. Adv. www.advancedsciencenews.com (Figure S5, Supporting Information). As long as the ratio of the of ratio the as long As Information). Supporting S5, (Figure precursors was kept above 1, the synthesis resulted in a highly Information). S17, Supporting emissive compound (Figure solution, and the precursor ratio was used to control the final the control to used was ratio precursor the and solution, product composition. A precursor ratio (CsBr/PbBr ratio was used to precipitate crystals in the mixed H mixed the in crystals precipitate to used was ratio solvent was used for CsBr. Precise control of the DMSO/H solvent was used for CsBr. to CsPbBr produce different proportions of Cs proportions produce different in-Cs ternary phase diagram (often called a Gibbs triangle) highlights called a Gibbs ternary phase diagram (often that various mixtures of the CsBr and PbBr Figure 3. spectra of a CsPbBr (DMSO) solvent was used for dissolving PbBr CsPbBr various cubic perovskite inclusions in each rhombic prism matrix. e) High-resolution transmission electron microscopy (HRTEM) image of a CsPbBr various cubic perovskite inclusions in each rhombic prism matrix. e) High-resolution transmission no intermediate phases. To overcome the different solubility of overcome the different no intermediate phases. To PbBr Communication 1605945 Figure 4. 375 nm.b)PLdecayforcrystalswith differentratiosofCsBrtoPbBr matching betweenperovskiteNCsandCs ysis ofthePL,SEM,XRD,ICP-AES,andtheoreticalphase deduced (Figure 3c). mation), fromwhicharatiobetweenCsPbBr sion spectrometry(ICP-AES)(Figure S2,Supporting Infor Pb atomicratiousinginductivelycoupledplasmaemis- showing acharacteristicCs of thecrystal.Figure 3eshowsaresultingTEM image,where crushed usingamortarandTEMwasperformedonthinchips microcrystal duetoitslargedimensions,thewas model in Figure 3d. As TEM could not be used to measure the offers themostdirectandconvincingcorroborationof (Figure S18,Supporting Information). sion, withverylittledegradationafter amonthofstorageinair properties. Furthermore, thematerialshowsstablelightemis- impurities would considerably affect the measured optical S4, Supporting Information), therefore, it is unlikely that these CsPbBr measured (whichwoulddecreaseinthepresenceofbulk-like present intheadmixture;however, highPLQYvalueswere rhombic prismsofCs CsPbBr ence ofasinglephase;arguingagainstthepossibilitythat (Figures S13–S15,Supporting Information)confirmthepres- sponding energy-dispersiveX-ray spectroscopy(EDS)mapp­ imaging (Figures S2–S4,Supporting Information)andcorre- in thematerialsystem.Wide areacompositionalSEM tice of the matrix (red) with the lattice of the NC (≈2.94 Å) of twooverlappinglatticefringes.Mixingthemeasuredlat- representing a Moiré fringe pattern resulting from the beating and aregionwithmuchlargerlatticespacingof13.2±0.1Å, experimental observations(inblue): in theMoiréequationyieldsapatternspacingconsistentwith It ispossiblethatmicrometricCsPbBr The dimensionsoftherhombicprismsrangefrom4–10µm. NCs (≈10nmdimensions)alignedtothelatticeofmatrix. CsPbBr pure-perovskite peaks).Anapproximatevalueoftheratio The XRDresultsindicatemorematrixthanNCs(i.e.,smaller www.advmat.de A detailedmaterialstructureemergesfromaggregateanal- Transmission electronmicroscopy (TEM),alongwithSAED, (4 of6) 3 3 3 ) thatwerenotnoticedinSEMimaging(Figures S2– toCs andCs Photophysical behavioroftheCsPbBr 4 PbBr 4 PbBr wileyonlinelibrary.com 6 isdeterminedbymeasuringtheCsto 4 6 PbBr arepresentasseparatebulkphases. 4 PbBr 6 thatcontainsmallcubicCsPbBr 6 latticespacingof3.4±0.1Å, 3 3 impuritiesarealso 4 -in-Cs PbBr 3 4 toCs 6 PbBr © (Figure 3d)— 2017WILEY-VCHVerlag GmbH &Co. KGaA,Weinheim 6 material.a)NormalizedPLEspectra oftheperovskiteNCsat515nmandmatrix 4 PbBr 2 6 ing . is is [31] 3 -

a sharppeakintheabsorptionspectrum. inside themicrocrystalsofCs tion), stronglycorroborating the existenceofperovskite NCs NCs canbeidentifiedin Figure S12(Supporting Informa- ference inSAEDpatternsbetweenregionswithandwithout tron beamhasdiffracted off asinglemicrocrystalchip.Thedif pattern on Figure 3f shows peaks ofboth phases after anelec- of NCemissionat515nm,andmatrix375 the NC inclusions. Photoluminescence excitation (PLE) spectra kite NCs, in defects(Figure 2b).AstheamountofPbBr growth isimpeded,leadingtosmaller, nonuniformNCshigh ther reduced(beyondaCsBr/PbBr included inFigures S10andS11(Supporting Information). With similarPLlifetimestothoseofcolloidalCsPbBr with thevalueslistedinTable S19(Supporting Information). Figure 4b. Multiexponential functions fit these decay traces, NCs inthematrixcompound,yieldingtracesshown CsBr. At thispoint,thereisverylittleCsPbBr tals becomesmaller, leavingasignificantamountofunreacted not reachtheNCs.Inthisregion,Cs ≈310 nm,wherelightisfullyabsorbedbythematrixanddoes are plottedinFigure passivation oftheNCsurface.At lowerCsBr/PbBr between theircubicperovskiteinclusions,resultinginthebest exhibit thehighestPLQY, duetosufficient spatialseparation the othersideofoptimum,atsmallamountsPbBr and adecreaseinPLQYduetohigherexcitondissociation.On bulk-like, thereforeexhibitingalossinquantumconfinement which isindicatedbyared-shift inPL.TheselargerNCsare decrease inPLQYcanbeattributedtothegrowingsizeofNCs, the passivatingCs istence ofCsPbBr sions of the expected NC. The SAED results evidence the coex- d Moir The widebandgapmatrixallowsfordirectphotoexcitationof A CsBr/PbBr PL decaymeasurementswereperformedonperovskite The sizeintheregionofinterestalsomatchesdimen- e = 2 () dd [13,34,35] Ma trix d NC 2 − 2 transientphotophysicsfurtherevidencesthat precursorratioof8yieldsmicrocrystalsthat 4 NC 3 PbBr andCs =± 10 6 4a. Notably, thereisasharpdipat matrix. 4 PbBr 3A 4 ° PbBr

6 withinthemicrocrystal.The 2 www.advancedsciencenews.com ratioof20),themicrocrys- 6 . Further TEMimagesare 4 [33] PbBr Adv. 3 2 andalsolittleof precursorisfur 6 Mater. matrixexhibits 2017, 1605945 2 ratios,a 3 perovs- 2 , NC (1) [32] - -

Communication

α K 1605945 (5 of 6) www.advmat.de January 11, 2017 November 3, 2016 Published online: 8123, 812308. Revised: Received: 2011, 7617, 76171A. 27, 8066. 2010, 24, 067804. 2015, 2015, wileyonlinelibrary.com 350, 1222. 8, 18189. 2015, 2016, 27, 2311. fs, each time step meant delaying the probe pulse with respect the probe pulse with respect step meant delaying fs, each time Zhang, T. L. Smith, M. A. Haase, X. Sun, B. Hao, J. Zhang, T. J. Miller, T. J. Thielen, Ballen, J. Xie, A. S. Barnes, F. Kecman, J. Yang, T. C. A. Leatherdale, R. Wirth, A. Biebersdorf, K. Engl, S. Groetsch, Proc. SPIE – Int. Soc. Opt. Eng. R. Do, ACS Appl. Y. H. Kang, S. Lee, J. H. Oh, H. Yang, H. C. Yoon, Interfaces Mater. R. Rivarola, S. D. Stranks, S. Pathak, N. Sakai, F. W. J. Liu, G. E. Eperon, C. Ducati, K. Wojciechowski, Griffiths, A. A. Haghighirad, A. Pellaroque, R. H. Friend, J. T. H. J. Snaith, Chem. Mater. H. Du, L. Cheng, X. Dai, , J. Si, Z. K. , Y. N. Wang, J. Wang, Mater. , Adv. W. M. L. , R. H. Friend, S. Bai, H. He, Z. Ye, 2015, C.-L. Lee, Kim, C. Wolf, H. Cho, S.-H. Jeong, M.-H. Park, Y.-H. S. H. Im, R. H. Friend, J. H. Heo, A. Sadhanala, N. Myoung, S. Yoo, Lee, Science T.-W. , J. Ding, C.-L. Mo, L.-Q. J.-L. Liu, J.-L. Zhang, G.-X. Wang, Fang, W.-Q. , S. Pan, C.-D. Zheng, X.-M. Z.-J. Quan, X.-L. Wang, Jiang, Chin. Phys. B F.-Y. Proc. SPIE Detchprohm, T. C. Wetzel, : The atomic Plasma Atomic Emission Spectrometry Inductively Coupled : The XRD measurements were collected at the MAX Diffraction XRD: The XRD measurements ≈350 [1] [3] [4] [5] [6] [7] [2] rotating anode, and Göebel cross-coupled parallel focusing mirrors. cross-coupled parallel focusing mirrors. rotating anode, and Göebel a performed with a 300 s frame exposure, Bisecting angle scans were cm, and an X-ray beam at 90 mA and 50 kV. detector distance of 16.740 was determined using ICP-AES, with the Perkin composition of samples were used as 1, 10, 100, 1000 ppm Pb and Cs Elmer Optima 7300DV. The perovskites in hexabromide samples standards for the calibration. were dissolved in 10% HCl before ICP-AES characterization. Acknowledgements authors wish work. The to this equally contributed and R.Q.-B. L.N.Q. R. Sabatini, and S. Hoogland for fruitful to acknowledge R. Comin, Furthermore, the work. presenting in and feedback discussions XRD Jim Britten for his help in performing the authors thank Dr. as well as the measurements, and OCCAM for their assistance, equipment. Density maintenance and availability of electron microscopy on the IBM BlueGene functional theory calculations were performed Ontario Smart Q supercomputer with support from the Southern Platform. Innovation Computing continuum (Ultrafast, Helios). With a temporal resolution of the system a temporal resolution (Ultrafast, Helios). With continuum of pump other Every exponentially. with time steps increasing to the pump, the ΔOD. in order to determine blocked with a chopper pulse was the pulses were measured spectrograph, through a grating After going device (Ultrafast, Helios). Multiple by means of a charge-coupled and the average of sample at each power, scans were taken for each the The traces were fitted to the convolution of these scans was used. a sum of the exponential decays. instrument response and Bruker Smart6000 CCD area using a at McMaster University, Facility a Rigaku RU200 Cu 3-circle D8 goniometer, detector with a Bruker Supporting Information Wiley Online Library or Supporting Information is available from the from the author. . The was m /DMSO [36] 2 of CsBr m (depending NCs and a 3 m ≈ 0.13 ns. The kHz repetition rate ). After bright green : Perovskite NCs in 2 O (deionized water). 6 matrix. 2 6 was fixed to 0.1 : 1–0.001 2 6 PbBr 4 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim KGaA, & Co. GmbH 2017 WILEY-VCH Verlag ratio of 1. This finding ratio of 1. This finding PbBr © 2 4 PbBr 4 microcrystals enables high microcrystals enables 6 perovskite NCs in robust and perovskite NCs in robust 3 nm light. The latter served as the (99.9%, Alfa Aesar) was dissolved 2 PbBr 4 = 375 nm) as the excitation source. The time resolution,

λ matrix is proposed. Powder XRD confirms the coex- XRD Powder matrix is proposed. 2017, 1605945 6 precursor solution were prepared via the same method precursor solution were prepared via the O solution was then slowly injected into the PbBr O solution was then slowly injected into the 6 2 Mater. PbBr PbBr Photoluminescence Measurements (Decay, Emission Spectroscopy, Emission Spectroscopy, Photoluminescence Measurements (Decay, Synthesis of Bulk Perovskite NCs in Cs Fabrication of Film Perovskite NCs in Cs Fabrication : Femtosecond laser pulses of Absorption Spectroscopy: Femtosecond Transient The synthesis of cubic CsPbBr The synthesis of cubic 4 4 Adv. www.advancedsciencenews.com solution and stirred at room temperature in air atmosphere for 30 min solution and stirred at room temperature in air to 2 h (depending on the concentration of PbBr series of precursor solution was then spin-coated on the glass substrate, series of precursor solution was then spin-coated (AFM) and transient followed by annealing, for atomic force microscopy measurements. absorption (TA) and PLQY): All PL measurements were done with a Horiba Fluorolog time correlated single photon counting system with a single grating Steady state PL and spectrometer and photomultiplier tube detector. PLE measurements were done using monochromatized light from a used a measurements xenon lamp as the excitation source. Transient laser diode ( Cs Cs standard published method for measuring quantum yields according to the instrument response function, is Δt air-stable rhombic prism Cs air-stable (99.999%, Aldrich) was dissolved in 300 µL H Experimental Section these NCs are responsible for the high PLQY emission. The the high PLQY emission. are responsible for these NCs lifetimes to compute radiative were further used PL lifetimes an increase evidencing Information), S19, Supporting (Table and of the NC is increased, lifetime as the size in radiative micro- the bulk-like perovskite a maximal value for approaching a CsBr/PbBr crystals produced with described above, but the concentration of PbBr istence of perovskite NCs and the matrix. SEM imaging and imaging SEM matrix. the and NCs perovskite of istence crystallites. Compound PL confirmed the shape and size of the measurements. TEM ratios were estimated from ICP-AES evidence in imaging and SAED patterns provide conclusive studies, including support of the material model. Photophysical the model. In sum, all PL decay and PLE spectra, corroborated with the picture of of the experimental characterizations agreed endotaxy of perovskite NCs with a Cs precipitates formed in the mixed solution, crystals were centrifugated at precipitates formed in the mixed solution, crystals drying under vacuum. 5000 rpm and washed with toluene, followed by in 1 mL DMSO (99.9%, Aldrich). At the same time, 1 in 1 mL DMSO (99.9%, Aldrich). At the same agrees with the material model, exhibiting a dramatic increase model, exhibiting a dramatic increase agrees with the material due to an increase in exciton dissociation in radiative lifetime increased into the bulk-like domain. as the size of a NC is CsBr/H used with a Quanta-Phi integrating sphere. Excitation and emission intensities were measured in empty-sphere, direct illumination, and indirect illumination configurations. Light was coupled between the Fluorolog system and the sphere with optical fiber bundles. The detector and integrating sphere were corrected for spectral variance using a calibrated white light source. at a 5 by a Yb:KGW laser 1030 nm generated parametric an optical through passed Pharos) Conversion, (Light Conversion, Orpheus) with the second harmonic amplifier (Light of the signal pulse selected for 400 pump pulse, whereas the probe pulse was generated by focusing the focusing by generated was pulse probe the whereas pulse, pump resulting in a white-light initial 1030 nm pulse into a sapphire crystal, on the ratio of precursors) of PbBr emission efficiency in the solid state (92% PLQY). A model model A PLQY). 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