Segregation Of Ions Research Articles

Efficient single-component white light emitting diodes enabled by lanthanide ions doped lead halide perovskites via controlling Förster energy transfer and specific defect clearance

Currently, a major challenge for metal-halide perovskite light emitting diodes (LEDs) is to achieve stable and efficient white light emission due to halide ion segregation. Herein, we report a promising method to fabricate white perovskite LEDs using lanthanide (Ln3+) ions doped CsPbCl3 perovskite nanocrystals (PeNCs). First, K+ ions are doped into the lattice to tune the perovskite bandgap by partially substituting Cs+ ions, which are well matched to the transition energy of some Ln3+ ions from the ground state to the excited state, thereby greatly improving the Förster energy transfer efficiency from excitons to Ln3+ ions. Then, creatine phosphate (CP), a phospholipid widely found in organisms, serves as a tightly binding surface-capping multi-functional ligand which regulates the film formation and enhances the optical and electrical properties of PeNC film. Consequently, the Eu3+ doped PeNCs based-white LEDs show a peak luminance of 1678 cd m-2 and a maximum external quantum efficiency (EQE) of 5.4%, demonstrating excellent performance among existing white PeNC LEDs from a single chip. Furthermore, the method of bandgap modulation and the defect passivation were generalized to other Ln3+ ions doped perovskite LEDs and successfully obtained improved electroluminescence (EL). This work demonstrates the comprehensive and universal strategies in the realization of highly efficient and stable white LEDs via single-component Ln3+ ions doped PeNCs, which provides an optimal solution for the development of low-cost and simple white perovskite LEDs.

Extremely enhanced thermal stability of Y2/3Cu3Ti4O12 ceramics by a Pechini method

AbstractY2/3Cu3Ti4O12 ceramic is a novel semiconductor with potential applications in electronic devices. However, its resistance drift and surface structure defects limit the application for negative temperature coefficient thermistor devices. A comparative study of solid‐phase and a Pechini processing of Y2/3Cu3Ti4O12 is presented in this paper, in the particular comparative study of stability. The Pechini method is found to be effective in lowering sintering temperature and improving thermal stability (ΔR/R0 < 0.3％) in comparison with solid‐phase method. The origin of the stability deterioration is related to the oxidation state of Cu ions and the migration of sublattice. The Pechini method overcomes stoichiometric ratio deviations and cation vacancy diffusion, thus reducing metal ion segregation in a continuous high‐temperature environment and thereby showing unique insensitivity to oxygen. The important role of the Pechini method in improving thermal stability is revealed, which is expected to be used in the preparation of high stability electron devices.

Metal-oxide nanocomposite catalyst simultaneously boosts the oxygen reduction reactivity and chemical stability of solid oxide fuel cell cathode

Conductive perovskite oxides have received much attention as promising candidates for solid oxide fuel cell (SOFC) cathodes. However, they show chemical instability due to the segregation of A-site cations on the surface at high temperatures, which causes their performance to degrade. Moreover, the high activation barrier to oxygen reduction reactions makes these materials more difficult to use as electrodes at lower temperatures (less than 700 °C). Herein, by combining two general techniques: nanoparticle infiltration and atomic layer deposition (ALD), we significantly improve both the durability and reactivity of a state-of-the-art perovskite oxide, La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF). Ag nanocatalysts are dispersed onto an LSCF cathode via wet infiltration, after which they are covered with a thin ZrO2 layer via ALD to prevent the agglomeration of nanocatalysts and the segregation of Sr ions. Accordingly, the Ag/ZrO2 nanocomposite-deposited LSCF cathode shows the electrode resistance of 0.085 Ωcm2 at 650 °C over 200 h, which is, to the best of our knowledge, the near-record level among all nanocatalyst-infiltrated LSCF cathode to date. Our result suggests a new research direction to fully utilize nanocatalysts and perovskite oxides in SOFCs, which can be a shortcut to their commercialization.

Efficient perovskite cathode for solid oxide fuel cells towards enhanced oxygen reduction activity and stability by water-mediated exsolution

Highly efficient and stable cathodes are significantly vital for solid oxide fuel cells (SOFCs). However, one of key impediment to the cathode development is the undesirable oxygen reduction activity and stability with exposure upon steam. Herein, we present a novel nanoparticles-decorated cathode, comprised of O2−/e−/H+ triple-conducting K+-doped BaCo0.7Fe0.2Y0.1O3-δ (Ba0.9K0.1Co0.7Fe0.2Y0.1O3-δ, BKCFY) matrix oxide and the mixed O2−/e− conducting nanoparticles of BaCoO3-δ (BCO) through water-mediated exsolution process, exhibiting high activity and robust stability with exposure upon the steam. The cathode shows a low polarization resistance of 0.048 Ω cm2 at 700 °C when exposed upon humid air with 3% H2O, approximately 24% lower than that in dry air (0.065 Ω cm2 at 700 °C). Such improvement is mainly ascribed to the exsolved BaCoO3-δ nanoparticles decorated on the porous BKCFY, which enlarged the triple phase boundary for oxygen reduction reaction. The increased oxygen vacancy concentration through K doping can accelerate the Ba and Co ions segregation to form BaCoO3-δ with exposure upon the wet condition. Furthermore, K+ dopant with higher basicity than Ba2+ is beneficial for hydration behavior, which effectively promotes the catalytic activity under the water vapor. Moreover, the exsolved BaCoO3-δ nanoparticles are socketed on the BKCFY matrix oxide, which ensures high stability for this hybrid cathode operated at 700 °C. The findings provide a promising approach to design the triple-conducting cathode for solid oxide fuel cells via water-mediated exsolution, which can also be applied for solid oxide electrolysis cells and membrane reactors.

Strongly Quantum-Confined Perovskite Nanowire Arrays for Color Tunable Blue Light-Emitting Diodes

Color tunability of perovskite light emitting diodes (PeLEDs) by mixed halide compositional engineering is one of the primary intriguing characteristics of PeLEDs. However, mixed halide PeLEDs are often susceptible to color red-shifting caused by halide ion segregation. In this work, strongly quantum-confined perovskite nanowires (QPNWs) made of CsPbBr3 are grown in nanoporous anodic alumina templates using a closed space sublimation (CSS) process. By tuning the pore size with atomic layer deposition (ALD), QPNWs with diameter of 6.6 nm to 2.8 nm have been successfully obtained, with continuous tunable photoluminescence emission color from green (512 nm) to pure blue (467 nm). To better understand the photo-physics of QPNWs, carrier dynamics and the benefit of alumina passivation are studied and discussed in detail. Eventually, PeLEDs using various diameters of CsPbBr3 QPNWs are successfully fabricated with cyan color (492 nm) PeLEDs achieving a record high 7.1% EQE for all CsPbBr3 based cyan color PeLEDs. And sky-blue (481 nm) and pure blue (467 nm) PeLEDs have also been successfully demonstrated, respectively. The work here demonstrates a unique approach to achieve quantum confined one-dimensional perovskite structures and color tunable PeLEDs, particularly blue PeLEDs.

Sensitivity of electrical behaviours of ZnO nanoparticle–Bi2O3–Mn2O3 varistor system to various La2O3 doping compositions

The effects of La2O3 on the behaviours of ZnO nanoparticle–Bi2O3–Mn2O3 varistors were determined. The discs with various La2O3 compositions (0.0–3.0 mol%) were prepared via traditional ceramic techniques and their characteristics were investigated. The results demonstrate that La2O3 remarkably affects the varistor samples, in which the size of grain diminished from 29.3 to 8.5 µm according to increasing La2O3 content from 0.0 to 3.0 mol%. The significant response within the varistor sample fabricated from ZnO nanoparticles through sintering process at 1200oC perhaps caused by the surface properties of the powdered ZnO nanoparticles. X-ray diffraction results show that the addition of La2O3 to the varistor resulted in additional peaks, which can be attributed to the construction of La-based phases through the sintering process at high temperature. The spinal phases of the (Bi48ZnO73) and (Mn3O4) diminish with the 3.0 mol% content of La2O3. The varistor samples with 2.0 mol% La2O3 show a superior spinal phase construction of (Bi48ZnO73) and (Mn3O4) and La-based phases, resulting in homogeneous grain size. La2O3 doping substantially enhanced the electrical behaviours of the disc sample with a notable increase in breakdown voltage from 2614.8 to 5730.7 V/mm caused by the increase in La2O3 doping concentration from 0.0% to 3.0 mol%. The improvement was associated with the potential lanthanide ion segregation caused by its greater ionic radius to the boundaries between ZnO grains, thus enhancing its electrical properties. Moderate La2O3 doping concentration at 1.0 mol% improved the non-linear characteristics of the sample (α = 66) and 4400 V/mm breakdown voltage was introduced, while a significant amount of La2O3 doping concentration (more than 1.0 mol%) caused its deterioration (α = 35). The increase in donor concentration Nd to 2.1 × 1020 cm−3 for the varistor doped with 1.0 mol% La2O3 is accompanied by a decrease of interfacial states density NIS to 2.2 × 1012 cm−2 eV−1, in addition to decrease in depletion layer ω to 3.9 nm. The leakage currents of the sample decreased from 0.473 to 0.310 mA/cm2 with the increase of La2O3 doping contents from 0.0% to 2.0 mol% and then increased to 0.596 mA/cm2 at 3.0 mol% La2O3 doping concentration. Therefore, La2O3 may be added to dominate the microstructural characteristics and electrical behaviours of ZnO–Bi2O3–Mn2O3 varistor manufactured using powdered ZnO nanoparticles.

Photo-induced macro/mesoscopic scale ion displacement in mixed-halide perovskites: ring structures and ionic plasma oscillations

Contrary to the common belief that the light-induced halide ion segregation in a mixed halide alloy occurs within the illuminated area, we find that the Br ions released by light are expelled from the illuminated area, which generates a macro/mesoscopic size anion ring surrounding the illuminated area, exhibiting a photoluminescence ring. This intriguing phenomenon can be explained as resulting from two counter-balancing effects: the outward diffusion of the light-induced free Br ions and the Coulombic force between the anion deficit and surplus region. Right after removing the illumination, the macro/mesoscopic scale ion displacement results in a built-in voltage of about 0.4 V between the ring and the center. Then, the displaced anions return to the illuminated area, and the restoring force leads to a damped ultra-low-frequency oscillatory ion motion, with a period of about 20–30 h and lasting over 100 h. This finding may be the first observation of an ionic plasma oscillation in solids. Our understanding and controlling the “ion segregation” demonstrate that it is possible to turn this commonly viewed “adverse phenomenon” into novel electronic applications, such as ionic patterning, self-destructive memory, and energy storage.

Size-controllable crown ether-embedded 2D nanosheets for the host-guest ion segregation and recovery: Insights from DFT simulations

The recovery of lithium ion from spent lithium sources and from seawater is a strategic way of complementing the existing natural sources to meet the rapid growth in demand. Crown ethers have shown remarkable selectivity in the host-guest extraction of several metal cations. Recent studies have shown that the macrocyclic polyether rings exhibit poor selectivity to lithium when competing with other metals of high abundance and similar cationic size. This study thus presents a strategy to improve the selective extraction of lithium on crown-embedded 2D materials using first principles density functional theory (DFT) simulations. Several ion transmission channels of 9-crown-3, 12-crown-4, 15-crown-5 and 18-crown-6 were created on graphene, hexagonal boron nitride and silicene nanosheets. Compared to the pristine crown ethers, the crown-embedded 2D materials exhibit rapid charge transfer, superior host-guest dipole-dipole interactions and higher Li+/Mg2+, Li+/Na+, Li+/K+ and Li+/Ca2+ selectivities while maintaining the properties of the 2D materials. Adsorption energies, Eads of −262.8, −605.1, −566.4 and −231.0 kcal/mol were calculated for the adsorption of Li+ ion on 12-crown-4, g-14-crown-4, b-14-crown-4 and s-14-crown-4, respectively. The sp3-hybridized low-buckled crown-4 passivated silicene nanosheet, having a narrower bandgap of 0.588 eV demonstrates the rapid diffusion of Li+ ion while slowing down other cations. The present study provides insights on the creation of ion-channels within silicene nanosheet to promote the host-guest selective recovery of lithium in the presence of abundant interfering ions such as in seawater, a prospect which could serve as a feasible strategy for meeting the rapidly thriving energy demand of the metal atoms.

The coordination number rule and its implications – a review

AbstractWe give a review on the coordination number rule and its implications. We demonstrate how even rather complex (non‐molecular) structures can be rationalized and sometimes even predicted starting from primary coordination numbers of cations only, and we show how connectivity formulas of a Niggli‐type can be inferred from such a simple starting point. Furthermore, we derive a measure to describe the segregation of different ions within the general matrix and we point out that it can be due not only to chemical disparities of the components but also to simple numerical relations between stoichiometric coefficients and coordination numbers. It can be shown that Pauling's electrostatic valence rule must sometimes necessarily be violated depending on such numerical relations. We finally address the principle of electrostatic balance as a driving force for creating certain topologies which seem surprising at first glance, and we may thereby help to “reconcile” with the “violations” of Pauling's rule.

Complete Perovskite Solar Cells with Gold Electrodes Studied in the Visible and Near-Infrared Ranges

Complete solar cells with the triple-cation perovskite (FA0.76MA0.19Cs0.05Pb(I0.81Br0.19)3) sandwiched between spiro-OMeTAD (2,2′,7,7′-tetrakis-(N,N-di-4methoxyphenylamino)-9,9′-spirobifluorene) and mesoporous titania layers were examined using femtosecond transient absorption (TA) and steady-state absorption in the visible and near-infrared (NIR) regions. We demonstrate in this paper that the transmission spectroscopic measurements through a gold layer are possible and open the way to investigate the solar cells in working conditions (with applied voltage and/or additional illumination). We show that a gold electrode does not exhibit a significant TA signal itself but causes a difference in the perovskite response at around 800 nm and in the NIR range. The irradiation with a femtosecond laser, 1 Sun stationary illumination, or applied voltage causes significant changes in the TA spectra and kinetics at the TiO2 interface, most probably due to ion segregation or ion rearrangement process. The transmission signal in the NIR range is shown to be dominated by spectral modulation due to light interference; however, the process of hole injection at spiro-OMeTAD interfaces can be extracted. Finally, application of an appropriate forward bias enables the suppression of electron and hole injection to contact materials and results in increased lifetime of charge population in the perovskite.

Nanofabrication and functional characterization of Co9-xNixS8 nanoparticles for optoelectronic applications

Different ratios of Co9-xNixS8 nanoparticles (2.6 ≤ x ≤ 3.4) were synthesized via the solvothermal technique. Spinel single phase of Co9S8 was detected for x = 2.6 and 3.4, while the impurity phase of cubic Co3O4 was also detected for x = 3.0 due to the segregation of some Co ions causing an obvious change in the interatomic distances of the tetrahedra (short/long) and octahedra of the solid solution Co9-xNixS8. XPS results indicated that Ni3+ cations were only existed in the structure of Co6·4Ni2·6S8, while Ni2+ and Ni3+ cations were located in the Ni-rich samples at x = 3.0 and 3.4. FTIR absorption bands of NiS bonds around 668 and 1036 cm−1 showed larger broadening with increasing Ni content. SEM images of Co6·4Ni2·6S8 revealed clusters of nanospheres that are coated with nanoplatelet carbon sheets. The bandgap energy of Co9-xNixS8 nanoparticles is gradually decreased with increasing Ni content. The sample with the lowest Ni content (x = 2.6) displayed the highest values of refractive index (n) and optical conductivity. The intensity of photoluminescence (PL) spectra for x = 3.0 was the highest emission due to the presence of secondary phase Co3O4 which increases the number of defect levels for trapping more excited electrons and preventing their rapid recombination with holes. The Ni-rich sample with very small refractive index and photoconduction could be a good candidate for antireflection coating materials.

Crowding of neodymium ions as a structural feature of fluorophosphate glasses

The rare-earth element of neodymium is used as a doping agent for a variety of alloys, as the base element for super magnets and in cryogenic industry. Inorganic glass industry represents a separate application for neodymium oxide. Having a high quantum yield of luminescence, such glasses are essential for the production of high-power optical quantum generators. Fluorophosphate glasses have a complex composition, specific physicochemical properties and spectral characteristics, and demonstrate specific matrix forming patterns when modifiers or glass forming agents are introduced. The current structural description of fluorophosphate glasses is lacking, which gives relevance to further studies into the structure of Ba(PO3)2 based pseudobinary glass system and barium fluoroaluminate. Microadditions of neodymium oxide were introduced as an activator during glass synthesis. Such glasses can be used as laser material. The authors examined the absorption and luminescence spectra of glass specimens containing neodymium. It is shown that fluorophosphate glasses are structurally heterogeneous systems that contain two typical activator coordination environments; introduction of fluorides in Ba(PO3)2 glass leads to neodymium ion segregation in the phosphate glass matrix. Specimens of crystallization resistant optical glass have been obtained. The paper describes optimum compositions of neodymium activated fluorophosphate glasses that retain the advantages of phosphate glass systems while shorter neodymium luminescence lifetimes have no noticeable impact on the glass performance.

Strongly Quantum-Confined Perovskite Nanowire Arrays for Color-Tunable Blue-Light-Emitting Diodes.

Color tunability of perovskite light-emitting diodes (PeLEDs) by mixed halide compositional engineering is one of the primary intriguing characteristics of PeLEDs. However, mixed halide PeLEDs are often susceptible to color red-shifting caused by halide ion segregation. In this work, strongly quantum-confined perovskite nanowires (QPNWs) made of CsPbBr3 are grown in nanoporous anodic alumina templates using a closed space sublimation process. By tuning the pore size with atomic layer deposition, QPNWs with a diameter of 6.6 to 2.8 nm have been successfully obtained, with continuous tunable photoluminescence emission color from green (512 nm) to pure blue (467 nm). To better understand the photophysics of QPNWs, carrier dynamics and the benefit of alumina passivation are studied and discussed in detail. Eventually, PeLEDs using various diameters of CsPbBr3 QPNWs are successfully fabricated with cyan color (492 nm) PeLEDs, achieving a record high 7.1% external quantum efficiency (EQE) for all CsPbBr3-based cyan color PeLEDs. Sky blue (481 nm) and pure blue (467 nm) PeLEDs have also been successfully demonstrated, respectively. The work here demonstrates a different approach to achieve quantum-confined one-dimensional perovskite structures and color-tunable PeLEDs, particularly blue PeLEDs.

Thermodynamic Calculations of Ti Ion Concentrations and Segregation Coefficients during Ti:Sapphire Crystal Growth

Thermodynamic Calculations of Ti Ion Concentrations and Segregation Coefficients during Ti:Sapphire Crystal Growth

Growth of samarium doped zinc tungstate crystals by the Czochralski method

The growth conditions to produce a high quality ZnWO4:Sm single crystals by the Czochralski method were determined in this work. The role of the Sm impurity in the formation of bubbles in a ZnWO4 single crystal is discussed. The Sm3+ ions segregation coefficient in the ZnWO4 single crystal was estimated to be 0.023. The effect of non-isomorphic substitution of Sm3 + for Zn2 + ions on the ZnWO4 crystal lattice parameters has been investigated. The X-ray luminescence spectra of ZnWO4:Sm3+ crystals are discussed. Two ZnWO4 crystals doped with samarium enriched in 148Sm and 149Sm isotopes were obtained following the established growth technique, which demonstrates its feasibility and reliability for production of detector for rare nuclear processes studies.

Tm,Ho:Ca(Gd,Lu)AlO4 crystals: Crystal growth, structure refinement and Judd-Ofelt analysis

“Mixed” calcium rare-earth aluminate laser host crystals Ca(Gd,Lu)AlO4 (CALGLO) with up to 10.8 at.% Lu codoped with Tm3+ and Ho3+ ions are grown by the Czochralski method along the [001] direction. The segregation of rare-earth ions is studied. The crystal structure is refined by the Rietveld method. Tm,Ho:Ca(Gd,Lu)AlO4 crystallizes in the tetragonal system (sp. gr. I4/mmm) exhibiting a K2NiF4 type structure. The lattice constants are a = 3.6585(6) Å and c = 11.9660(9) Å for a crystal with a composition of CaGd0.8947Lu0.0551Tm0.0448Ho0.0054AlO4. The stability of Ca(Gd,Lu)AlO4 solid-solutions is discussed. The polarized Raman spectra are measured, revealing a most intense mode at 311 cm−1 and a maximum phonon frequency of ∼650 cm−1. The polarized absorption spectra are measured. The transition intensities for the Ho3+ ion are analyzed using the modified Judd-Ofelt theory accounting for configuration interaction.

Alkali Additives Enable Efficient Large Area (>55 cm2) Slot‐Die Coated Perovskite Solar Modules

AbstractTypical fabrication methods for laboratory‐scale (<1 cm2) perovskite solar cells (PSCs) are undeniably not scalable and the control of crystallization of large‐area perovskite layer for commercial sized modules is also particularly challenging. Here, a seed‐assisted crystallization approach is demonstrated through addition of alkali salts, CsPbBr3 and KPb2Br5, to the perovskite precursor ink for enabling homogeneous and highly crystalline large‐area Cs0.15FA0.85Pb(I0.83Br0.17)3 (CsFA) perovskite films via scalable slot‐die coating technique. X‐ray photoelectron spectroscopy analysis reveals the segregation of potassium ions at SnO2/perovskite interface which serve as nucleation sites for the crystallization of perovskite layer. The uniformly slot‐die coated CsFA films (100 cm2) from the additives containing precursor inks possess larger grains with enhanced optoelectronic properties and the corresponding devices display higher reproducibility and consistency. A champion device efficiency of 18.94% under 1 sun illumination for slot‐die coated PSCs in n‐type/intrinsic/p‐type structure is demonstrated with improved stability with 82% of its initial efficiency tested at 65 °C for 1150 h. The slot‐die coated methylammonium‐free perovskite module with an active area of 57.5 cm2 shows an efficiency of 16.22% and retains 82% of its initial efficiency after 4800 h under 30% relative humidity without encapsulation.

Halide Ions Distribution and Charge Dynamics in Mixed‐Halide Perovskites

Owing to the striking properties, perovskite materials have clutched the interest in the field of optoelectronics. The property of being band tunable via composition alteration makes the perovskites fit in many optoelectronic applications. However, the compositional instability of mixed‐halide perovskites (MHPs) under illumination or by charge‐carrier injection is intercepting the exploitation of mixed‐halide strategy which effectively tailors the perovskite's bandgap. Herein, the segregation of halide ions in lattice promotes the formation of individual halide‐rich domains that severely influence the electronic band structures of the MHPs. In this scenario, extensive research is heading to perceive the mechanisms that drive the halide segregation and abate the process accordingly. As the impact of ion segregation directly determines the performance of the devices, in‐depth understanding is a prerequisite. This perspective provides a compressive understanding of different aspects such as structural origin, influence of light intensity, temperature, and atmospheric conditions that root the segregation process. A rigorous analytical discussion on approaches to play with cations and anions compositions, dimensionality, and Lewis base treatment that are detrimental for the halide segregation process is presented. This perspective contains a critical view on the halide segregation process that paves the route for future research.

Nanoscale chemistry and ion segregation in zirconia-based ceramic at grain boundaries by atom probe tomography

In this work nanoscale features that are of importance in the stability of yttria-stabilized tetragonal zirconia (Y-TZP) are quantified through atom probe tomography. In-depth analysis of grain boundary chemistry revealed preferential segregation of lighter and smaller ions towards specific grain boundaries. The relationship between elemental segregation and the local atomistic structure is investigated at the sub-nanometer level to gain insights on nanoscale features associated with the tetragonal-monoclinic phase transformation in Y-TZP through grain boundary characterization. Principal component analysis was implemented to reveal any potential biases from varied field evaporation across stabilizer-rich grain boundaries. The observed variations in ion density across different grains suggested a variation in field which was attributed to potential variations in grain crystal orientation. In order to reveal the subtle depletion of oxygen atoms within grain boundaries a new methodology to map oxygen vacancies is proposed, utilizing the relative neighborhood chemistry of individual yttrium atoms.

A-Site FA+ Doping-Enhanced Photoluminescence Efficiency and Photostability of Mn-Doped Perovskite Nanocrystals

Improving the optical and structural stability of highly luminescent Mn2+-doped CsPbCl3–yBry (Mn:CsPbCl3–yBry) nanocrystals (NCs) under ultraviolet illumination is very necessary for their application in solid-state lighting. Herein, greatly improved photoluminescence (PL) quantum yield (QY) and illumination stability were observed in Mn:CsPbCl3 NCs by incorporation of an appropriate FA+ amount into the crystal lattice. The Mn:FAxCs1–xPbCl3 NCs showed higher PL QYs (up to 76%), longer Mn2+ PL lifetimes, and nearly single-exponential decay relative to the Mn:CsPbCl3 ones. With the increase in irradiation time, a slowly reduced PL intensity and an almost unchanged PL peak position and linewidth of Mn2+ ions in Mn:FA0.15Cs0.85PbCl3 NCs were found, suggesting that the mixing of FA+ and Cs+ can increase the tolerance of the lattice and improve the photostability of the NCs. Under high-power ultraviolet irradiation, the light-induced Mn2+ PL attenuation of Mn:FA0.15Cs0.85PbCl3 NCs was slower than that of the ones without FA+, and no divisive emission peaks representing Br-rich and Cl-rich regions appeared in Mn:FA0.15Cs0.85PbCl3–yBry NCs, which was consistent with the result that the X-ray diffraction peaks of the NCs with FA+ remained constant with irradiation time. This indicates that severe Mn2+ ion diffusion and halogen ion segregation can be effectively inhibited by adding FA+ into the Mn-doped perovskite NCs.