Photoluminescence Behavior of Zero-Dimensional Manganese Halide Tetrahedra Embedded in Conjugated Organic Matrices

Unlocking the Potential of Organic-Inorganic Hybrid Manganese Halides for Advanced Optoelectronic Applications

Organic-inorganic hybrid manganese(II) halides (OIMnHs) have garnered tremendous interest across a wide array of research fields owing to their outstanding optical properties, abundant structural diversity, low-cost solution processibility, and low toxicity, which make them extremely suitable for use as a new class of luminescent materials for various optoelectronic applications. Over the past years, a plethora of OIMnHs with different structural dimensionalities and multifunctionalities such as efficient photoluminescence (PL), radioluminescence, circularly polarized luminescence, and mechanoluminescence have been newly created by judicious screening of the organic cations and inorganic Mn(II) polyhedra. Specifically, through precise molecular and structural engineering, a series of OIMnHs with near-unity PL quantum yields, high anti-thermal quenching properties, and excellent stability in harsh conditions have been devised and explored for applications in light-emitting diodes (LEDs), X-ray scintillators, multimodal anti-counterfeiting, and fluorescent sensing. In this review, the latest advancements in the development of OIMnHs as efficient light-emitting materials are summarized, which covers from their fundamental physicochemical properties to advanced optoelectronic applications, with an emphasis on the structural and functionality design especially for LEDs and X-ray detection and imaging. Current challenges and future efforts to unlock the potentials of these promising materials are also envisioned.

Crystal-Rigidifying Strategy in Hybrid Manganese Halide to Achieve Narrow Green Emission and High Structural Stability

Although organic-inorganic hybrid Mn2+ halides have advanced significantly, achieving high stability and narrow-band emission remains enormously challenging owing to the weak ionic nature and soft crystal lattice of the halide structure. To address these issues, we proposed a cationic engineering strategy of long-range cation π···π stacking and C-H···π interactions to simultaneously improve the crystal structural stability and rigidity. Herein, two organic zero-dimensional (0D) manganese halide hybrids of (BACQ)2MnX4 [BACQ = 4-(butylamino)-7-chloroquinolin-1-ium; X = Cl and Br] were synthesized. (BACQ)2MnX4 display strong green-light emissions with the narrowest full width at half-maximum (fwhm) of 39 nm, which is significantly smaller than those of commercial green phosphor β-SiAlON:Eu2+ and most of reported manganese halides. Detailed Hirshfeld surface analyses demonstrate the rigid environment around the [MnX4]2- units originating from the interactions between [BACQ]+. The rigid crystal structure weakens the electron-phonon coupling and renders narrow fwhm of these manganese halides, which is further confirmed by temperature-dependent emission spectra. Remarkably, (BACQ)2MnX4 realizes outstanding structural and luminescence stabilities in various extreme environments. Benefiting from the excellent performance, these Mn2+ halides are used to assemble light-emitting diodes with a wide color gamut of 105% of the National Television System Committee 1931 standard, showcasing the advanced applications in liquid-crystal-display backlighting.

Ultrafast Visual Detection of a Trace Amount of Water by Highly Efficient Hybrid Manganese Halides

A quantitative water detection method is urgently needed in storage facilities, space exploration, and the chemical industry. Although numerous physical techniques have been widely utilized to determine the water content, they still suffer from many disadvantages such as highly expensive special instruments, complicated analysis processes, etc. Hence, a convenient, rapid, and sensitive water analysis method is highly desirable. Herein, we developed a visual fluorescence sensing technology for water detection based on reversible PL off-on switching of organic-inorganic hybrid zero-dimensional (0D) manganese halides. In this work, a family of hybrid manganese halides were synthesized through a facile solution method, namely, [NH4(18-Crown-6)]2MnBr4, [Ca(18-Crown-6)·3H2O](18-Crown-6)MnBr4, [NH4(dibenzo-18-Crown-6)]2MnBr4, and [Ca(dibenzo-18-Crown-6)·2H2O]MnBr4. Excited by UV light, these highly crystalline manganese halides exhibit strong green light emissions from the d-d electron transition of Mn2+ with near-unity photoluminescence quantum yield and submillisecond lifetime. Benefiting from the dynamic and weak ionic bonding interactions, these 0D manganese halides display reversible water-response on/off luminescence switching but fail in any other aprotic solvents. Therefore, these 0D hybrid manganese halides can be explored as ultrafast visual fluorescence probes to detect the trace amount of water in organic solvents with multiple superiorities of rapid response time (< 2 s), ultralow detection limit (9.71 ppm), excellent repeatability, etc. The reversible water-response luminescent on/off switching also provides a binary optical gate with advanced applications in anticounterfeiting and information security, etc.

Mn-Doped M2CdCl4 (M = CH3NH3+, C2H8N+, and C3H10N+) Layered Hybrid Perovskite and Its Flexible Film Based on Simple Mechanochemical Synthesis

Layered hybrid perovskites show significant advantages in the field of optoelectronics. However, the low quantum efficiency and complex preparation methods limit their applications. In this work, we developed a series of perovskite powders with a two-dimensional (2D) layered structure of organic-inorganic hybrid metal halides M2CdCl4:x%Mn (M = CH3NH3+, C2H8N+, C3H10N+) via facile mechanochemical methods. The prepared manganese Mn-doped MA2CdCl4 produces orange emission at 605 nm under both 254 and 420 nm excitation, which originates from a dual excitation channel competition mechanism, and its excitation channel could be changed with the increase of Mn2+ ion concentration. Typically, MA2CdCl4:20%Mn powder exhibits high photoluminescence quantum yield (PLQY) close to 90% at 605 nm due to the organic amine ions enlarging the Mn-Mn interlayer distances. In addition, we prepared MA2CdCl4:x%Mn@PVA flexible films, which also exhibit good luminescence at 254 nm excitation and were unexpectedly found to have a better response to Cs+, which could be a candidate for anticounterfeiting applications.

Near-Unity Green Luminescent Hybrid Manganese Halides as X-ray Scintillators

The increasing demands in optoelectronic applications have driven the advancement of organic-inorganic hybrid metal halides (OIMHs), owing to their exceptional optical and scintillation properties. Among them, zero-dimensional (0D) low-toxic manganese-based scintillators have garnered significant interest due to their exceptional optical transparency and elevated photoluminescence quantum yields (PLQYs), making them promising for colorful light-emitting diodes and X-ray imaging applications. In this study, two OIMH single crystals of (Br-PrTPP)2MnBr4 (Br-PrTPP = (3-bromopropyl) triphenylphosphonium) and (Br-BuTPP)2MnBr4 (Br-BuTPP = (4-bromobutyl) triphenylphosphonium) were prepared via a facile saturated crystallization method. Benefiting from the tetrahedrally coordinated [MnBr4]2- polyhedron, both of them exhibited strong green emissions peaked at 517 nm owing to the d-d electron transition of Mn2+ with near-unity PLQYs of 99.33 and 86.85%, respectively. Moreover, benefiting from the high optical transparencies and remarkable luminescence properties, these manganese halides also exhibit excellent radioluminescent performance with the highest light yield of up to 68,000 photons MeV-1, negligible afterglow (0.4 ms), and linear response to X-ray dose rate with the lowest detection limit of 45 nGyair s-1. In X-ray imaging, the flexible film made by the composite of (Br-PrTPP)2MnBr4 and PDMS shows an ultrahigh spatial resolution of 12.78 lp mm-1, which provides a potential visualization tool for X-ray radiography.

High-Efficiency Narrow-Band Green-Emitting Manganese(II) Halide for Multifunctional Applications

Zero-dimensional (0D) Mn2+-based metal halides used as luminescent materials and scintillators have become a research hotspot in the field of photoelectric materials and devices due to their unique composition, structure, and fluorescence properties. It is of great value to explore new Mn2+-based metal halides to achieve multifunctional applications. Herein, the novel 0D Mn2+-based metal halide single crystal (BPTP)2MnBr4 is synthesized by a simple solvent-antisolvent recrystallization method. Under excitation at 468 nm, the (BPTP)2MnBr4 single crystal shows a pronounced narrow-band green luminescence centered at 515 nm derived from the d-d transition of the Mn2+ ion. This emission has a relatively narrow full width at half maximum of 43 nm and a high photoluminescence quantum yield (PLQY) of 82%. In addition, (BPTP)2MnBr4 exhibits good thermal stability at 393 K with a retention of 79% of the initial photoluminescence intensity at 298 K. Benefiting from its strong blue light excitation, high PLQY, and good thermal stability, we manufacture an ideal white light-emitting diode (LED) device using a 460 nm blue LED chip, green-emitting (BPTP)2MnBr4, and commercial K2SiF6:Mn4+ red phosphor. Under 20 mA drive current, the LED shows a high luminous efficiency of 112 lm/W and a wide color gamut of 110.8%, according to the National Television System Committee standard. In addition, (BPTP)2MnBr4 crystals show a strong X-ray absorption. Based on the commercial Lu3Al5O12:Ce3+ scintillator, the calculated light yield of (BPTP)2MnBr4 reaches up to about 136,000 photons/MeV and the detection limit reaches 0.282 μGyair s-1. Additionally, a melt quenching approach is used to construct a (BPTP)2MnBr4 clear glass scintillation screen, realizing a spatial resolution of 10.1 lp/mm. The proper performances of (BPTP)2MnBr4 as phosphor-converted LED materials and the X-ray scintillator with the addition of eco-friendly, low-cost solution processability make 0D Mn2+-based metal halides potential luminescent materials for multifunctional applications.

Satellite Red Emission from a Single Green-Emissive MnBr42- Tetrahedron in Soft Hybrid Single Crystals

Photoinduced self-trapped exciton emission is common in soft matter metal halide semiconductors, whereas analogous phenomena in metal halide insulators with localized emitting centers and delayed satellite emission have rarely been identified. In this study, a new zero-dimensional Mn(II) hybrid of [3DPTPP]MnBr4 (3DPTPP = (3-(dimethylamino)propyl)(triphenyl)phosphonium) with only one crystallographic Mn2+ site but dual emission is reported. The delayed red emission (∼630 nm) is successfully assigned to a satellite of the green-emissive (∼530 nm) MnBr42- tetrahedron shifted by N-H vibration (∼2500 cm-1), directly evidenced by the Raman spectra and further supported by density functional theory calculation. The photoluminescence decay curves demonstrate their same origin, but the red emission exhibits a delayed process. The temperature- and pressure-dependent PL spectra, temperature-dependent distortion of the MnBr42- tetrahedron, and light polarization spectra confirmed the consistency and distinctness of the dual emission. This study will inspire further research on self-trapped optoelectronic processes in soft metal halides.

Halogen Bond Induced Structural and Photophysical Properties Modification in Organic-Inorganic Hybrid Manganese Halides

The role of halogen bonding in organic-inorganic hybrid (OIH) halides was seldom investigated despite its potential to enhance the stability of the compound. In this context, we have synthesized (2-methylbenzimidazolium)MnCl₃(H₂O)·H₂O (compound 1) crystallizing in a monoclinic space group P2₁/c with a 1D infinite chain of edge shared Mn octahedra. In contrast, the chloro-substituted derivative (5-chloro-2-methylbenzimidazolium)₂MnCl₄ (compound 2) exhibits 0D Mn tetrahedra with a triclinic P1̅ structure. This structural modification from 1D Mn octahedra to 0D Mn tetrahedra involves a unique type-II halogen bonding between organic chlorine (C-Cl) and inorganic chloride (Cl-Mn) ions. Compound 1 exhibits red emission, whereas compound 2 demonstrates dual-band emission, resulting from energy transfer from the organic amine to Mn centers. To rationalize this interesting modulation in structure and photophysical properties, the role of halogen bonding is explored in terms of quantitative electron density analysis and intermolecular interaction energies.

Solution-Processed Hybrid Europium (II) Iodide Scintillator for Sensitive X-Ray Detection

Lead halide perovskite nanocrystals have recently demonstrated great potential as x-ray scintillators, yet they still suffer toxicity issues, inferior light yield (LY) caused by severe self-absorption. Nontoxic bivalent europium ions (Eu2+) with intrinsically efficient and self-absorption-free d-f transition are a prospective replacement for the toxic Pb2+. Here, we demonstrated solution-processed organic-inorganic hybrid halide BA10EuI12 (BA denotes C4H9NH4+) single crystals for the first time. BA10EuI12 was crystallized in a monoclinic space group of P21/c, with photoactive sites of [EuI6]4- octahedra isolated by BA+ cations, which exhibited high photoluminescence quantum yield of 72.5% and large Stokes shift of 97 nm. These properties enable an appreciable LY value of 79.6% of LYSO (equivalent to ~27,000 photons per MeV) for BA10EuI12. Moreover, BA10EuI12 shows a short excited-state lifetime (151 ns) due to the parity-allowed d-f transition, which boosts the potential of BA10EuI12 for use in real-time dynamic imaging and computer tomography applications. In addition, BA10EuI12 demonstrates a decent linear scintillation response ranging from 9.21 μGyair s-1 to 145 μGyair s-1 and a detection limit as low as 5.83 nGyair s-1. The x-ray imaging measurement was performed using BA10EuI12 polystyrene (PS) composite film as a scintillation screen, which exhibited clear images of objects under x-ray irradiation. The spatial resolution was determined to be 8.95 lp mm-1 at modulation transfer function = 0.2 for BA10EuI12/PS composite scintillation screen. We anticipate that this work will stimulate the exploration of d-f transition lanthanide metal halides for sensitive x-ray scintillators.

Excited-State Dopant-Host Energy-Level Alignment: Toward a Better Understanding of the Photoluminescence Behaviors of Doped Phosphors

Luminescent materials, also known as phosphors, have been widely used for applications such as emissive displays, fluorescent lamps, light-emitting diodes, and X-ray scintillation detectors. The energy-level diagram of a phosphor is extremely important for understanding its photoluminescence behavior. Here, we demonstrate through a combined density functional theory and experimental study that excited-state energy-level alignment accounts for the photoluminescence behaviors much better than ground-state energy-level alignment. An efficient doped phosphor should exhibit a type I excited-state dopant-host energy-level alignment, regardless of whether its ground-state alignment is type I. A type II excited-state dopant-host energy-level alignment implies that exciton dissociation, resulting in photoluminescence quenching. Our results provide not only a better understanding of the photoluminescence behaviors of the reported phosphors but also critical guidance for designing prospective luminescent materials.

Ultrasensitive Optical Thermometry via Inhibiting the Energy Transfer in Zero-Dimensional Lead-Free Metal Halide Single Crystals

Self-referencing optical thermometry based on the fluorescence intensity ratio (FIR) have drawn extensive attention as a result of their high sensitivity and non-invasively fast response to temperature. However, it is a great challenge for luminescent materials to achieve simultaneously high absolute and relative temperature sensitivity based on the FIR technique. Herein, we developed a novel optical thermometer by designing hybrid lead-free metal halide (TTPhP)₂MnCl₄:Sb³⁺ (TTPhP⁺ = tetraphenylphosphonium cation) single crystals with multimodal photoluminescence (PL). The large TTPhP⁺ organic chain resulted in isolated [MnCl₄]^2- and [SbCl₅]^2- in the single crystal, which leads to a negligible energy trasfer process within them. Therefore, the two PL bands (band 1 from [MnCl₄]^2-) with a peak at 518 nm and band 2 (from [SbCl₅]²) with a peak at 640 nm exhibit different thermal-quenching effects, which resulted in excellent temperature sensitivity, with the maximum absolute and relative sensitivities reaching 0.236 K^-1 and 3.77% K^-1 in a temperature range from 300 to 400 K. Both the absolute and relative sensitivities are among the highest values for luminescence thermometry.

Competing Energy Transfer in Two-Dimensional Mn2+-Doped BDACdBr4 Hybrid Layered Perovskites with Near-Unity Photoluminescence Quantum Yield

Two-dimensional (2D) hybrid layered perovskites (HLPs) have attracted extensive attention due to their excellent optoelectronic properties. Herein, we successfully prepared high-quality Mn-doped BDACdBr₄ (BDA = NH₂(CH₂)₄NH₂, butylene diammonium) HLP single crystals (SCs). The incorporation of Mn²⁺ ions modulates the electronic band structure of BDACdBr₄ perovskites and tailors the energy transfer process of excited states. A near-unity photoluminescence (PL) quantum yield of 96% from the Mn²⁺ emission at 608 nm is achieved. Excitation wavelength-dependent spectroscopic characterizations help to clarify the energy transfer mechanism of Mn-doped BDACdBr₄, in which competing PL from the ³E_g → ¹A_1g transition of Cd²⁺ and the ⁴T₁(G) → ⁶A₁(S) transition of Mn²⁺ dopants is observed. Temperature-dependent PL spectroscopic characterizations indicate that the efficient energy transfer from BDACdBr₄ perovskite host to Mn²⁺ dopants requires thermal activation to overcome a potential barrier. This work provides new insight into the photophysics and optical properties of 2D HLPs, especially the influence of Mn²⁺ doping on competing energy transfer in hybrid luminescent materials.

Improving the Chemical Stability of Narrow-Band Green-Emitting Manganese(II) Hybrid by Zn-Doping

Hybrid tetrahedral Mn(II)-based halides show great potential for narrow-band green emitters, which could be applied in the liquid crystal display field. However, the strategy to improve the chemical stability of tetrahedral Mn hybrids has not been fully investigated. Here, we demonstrate that Zn doping can be an effective route to significantly improve the stability of tetrahedral Mn hybrids under air conditions without compromising the luminous efficiency. A new bromide (ABI)₂MnBr₄ (ABI = 2-aminobenzimidazole) is synthesized, which exhibits a typical zero-dimensional structure with isolated [MnBr₄]^2- tetrahedra in the P1̅ space group. Under 450 nm excitation, a narrow-band green-emitting peak at 516 nm is observed with a full width at half maximum of 42 nm. It is indicated that spontaneous phase transition from the tetrahedral to octahedral motif occurs in this Mn hybrid driven by humidity, combined with the emission color change from green to red. Interestingly, this phase transition could be strongly suppressed by Zn doping with a very low doping amount (5%), leading to the significantly improved chemical stability of (ABI)₂MnBr₄ without reducing the photoluminescence quantum yield. Our work provides a simple and feasible strategy to enhance the chemical stability of the green-emitting (ABI)₂MnBr₄, and it may also be applicable for other tetrahedral Mn-based hybrids.

Ligand Engineering Triggered Efficiency Tunable Emission in Zero-Dimensional Manganese Hybrids for White Light-Emitting Diodes

Zero-dimensional (0D) hybrid manganese halides have emerged as promising platforms for the white light-emitting diodes (w-LEDs) owing to their excellent optical properties. Necessary for researching on the structure-activity relationship of photoluminescence (PL), the novel manganese bromides (C₁₃H₁₄N)₂MnBr₄ and (C₁₃H₂₆N)₂MnBr₄ are reported by screening two ligands with similar atomic arrangements but various steric configurations. It is found that (C₁₃H₁₄N)₂MnBr₄ with planar configuration tends to promote a stronger electron-phonon coupling, crystal filed effect and concentration-quenching effect than (C₁₃H₂₆N)₂MnBr₄ with chair configuration, resulting in the broadband emission (FWHM = 63 nm) to peak at 539 nm with a large Stokes shift (70 nm) and a relatively low photoluminescence quantum yield (PLQY) (46.23%), which makes for the potential application (LED-1, Ra = 82.1) in solid-state lighting. In contrast, (C₁₃H₂₆N)₂MnBr₄ exhibits a narrowband emission (FWHM = 44 nm) which peaked at 515 nm with a small Stokes shift (47 nm) and a high PLQY of 64.60%, and the as-fabricated white LED-2 reaches a wide colour gamut of 107.8% National Television Standards Committee (NTSC), thus highlighting the immeasurable application prospects in solid-state display. This work clarifies the significance of the spatial configuration of organic cations in hybrids perovskites and enriches the design ideas for function-oriented low-dimensional emitters.

Highly Distorted Antimony(III) Chloride [Sb2 Cl8 ]2- Dimers for Near-Infrared Luminescence up to 1070 nm

Zero-dimensional (0D) hybrid metal halides with unique compositional and structural tunability appear as an emerging class of luminescent materials, but near-infrared (NIR) emitters therein are largely unexplored to date. This study presents three novel 0D hybrid antimony chlorines with edge-sharing [Sb₂ Cl₈ ]^2- dimers, showing unusual room-temperature broadband NIR emission with the maximum emission wavelength up to 1070 nm. Photoluminescence studies and density functional theory calculation demonstrate that the emissions originate from the highly localized excitons, and that the confined [Sb₂ Cl₈ ]^2- dimers in these structures show low symmetry and a large degree of structural freedom. These hybrid antimony chlorines with [Sb₂ Cl₈ ]^2- dimers expand the range of new NIR materials in 0D metal halides.

Integrated Afterglow and Self-Trapped Exciton Emissions in Hybrid Metal Halides for Anti-Counterfeiting Applications

0D hybrid metal halides (0D HMHs) are considered to be promising luminescent emitters. 0D HMHs commonly exhibit self-trapped exciton (STE) emissions originating from the inorganic metal halide anion units. Exploring and utilizing the emission features of the organic cation units in 0D HMHs is highly desired to enrich their optical properties as multifunctional luminescent materials. Here, tunable emissions from organic and inorganic units are successfully achieved in triphenylsulfonium (Ph₃ S⁺ )-based 0D HMHs. Notably, integrated afterglow and STE emissions with adjustable intensities are obtained in (Ph₃ S)₂ Sn_{1- x} Te_x Cl₆ (x = 0-1) via the delicate combination of [SnCl₆ ]^2- and [TeCl₆ ]^2- . Moreover, such a strategy can be readily extended to develop other HMH materials with intriguing optical properties. As a demonstration, 0D (Ph₃ S)₂ Zn_{1- x} Mn_x Cl₄ (x = 0-1) are constructed to achieve integrated afterglow and Mn²⁺ d-d emissions with high efficiency. Consequently, these novel 0D HMHs with colorful afterglow and STE emissions are applied in multiple anti-counterfeiting applications.

Light Emission Enhancement of (C3H10N)4Pb1-xMnxBr6 Metal-Halide Powders by the Dielectric Confinement Effect of a Nanosized Water Layer

Organic-inorganic hybrid metal halides have been widely studied as a kind of phosphor materials for high-performance white light-emitting diodes. In this paper, a series of organic-inorganic metal-halide (C₃H₁₀N)₄Pb_1-xMn_xBr₆ powders with different Mn²⁺ ion doping concentrations were synthesized by mechanochemical methods, giving broadband white light emission with a photoluminescence quantum yield of 36.1% at room temperature, which turn green with a much larger intensity at 80 K. Interestingly, its emission converted from white to red after 100 °C treatments and turned back to white again when exposed to moist air for a while. This emission variation was caused by the adsorbed water layer on the surface of product powders via the dielectric confinement. The red emission from no water powders is identified to occur from the Mn ferromagnetic pair in point-shared octahedral sites, while the broadband white emission originated from the surface water-assisted dielectric confinement and surface polarization which combine the self-trapped excitons and d-d transitions of Mn ions and Mn pairs in the product. Moreover, this white emission can transform into green color at 80 K with a much stronger intensity, caused by the even efficient surface dielectric confinement by the adsorbed frozen water layer. This special compound has the advantages of simple preparation, low cost, and good stability and even contains water molecule in the air, giving a near-perfect white emission, with CIE of (0.33, 0.35) and correlated color temperatures at around 5733 K, which may be used for different applications such as sensing, solid-state lighting, and display.

Enhanced Photoluminescence of All-Inorganic Manganese Halide Perovskite-Analogue Nanocrystals by Lead Ion Incorporation

Herein, we develop an effective approach for incorporating lead (Pb) ions into manganese (Mn) halide perovskite-analogue nanocrystals (PA NCs) of CsMn(Cl/Br)₃·2H₂O via room-temperature supersaturation recrystallization. Pb²⁺-incorporated Mn-PA NCs exhibit strong orange emission upon UV light illumination, a peak centered at 600 nm assigned to Mn²⁺ transition (⁴T_1g → ⁶A_1g) with a photoluminescence quantum yield (PLQY) of 41.8% compared to the pristine Mn-PA NCs with very weak PL (PLQY = 0.10%). The significant enhancement of PLQY is attributed to the formation of [Mn(Cl/Br)₄(OH)₂]^4--[Pb(Cl/Br)₄(OH)₂]^4--[Mn(Cl/Br)₄(OH)₂]^4- chain network structure, in which Pb²⁺ effectively dilutes the Mn²⁺ concentration to reduce magnetic coupling between Mn²⁺ pairs to relax the spin and parity selection rules. In addition, excited energy can effectively transfer from the [Pb(Cl/Br)₄(OH)₂]^4- unit to Mn²⁺ luminescence centers owing to the low activation energy. Pb²⁺-incorporated PA NCs also exhibit excellent stability. The combined strong PL and high stability make Pb²⁺-incorporated Mn-based PA NCs an excellent candidate for potential optronic applications.