Confinement of Perovskite‐QDs within a Single MOF Crystal for Significantly Enhanced Multiphoton Excited Luminescence

Abstract

and then generate a high-energy photon through radiation transitions from the excited state. Compared with single photon excited luminescence, MPE luminescence has the advantages of stronger spatial confinement, longer penetration depth, smaller biological damage, and less Rayleigh scattering, so the high-order MPE luminescence materials have great potential applications in bioimaging, 3D optical data storage, sensing, and so on, but basically have not been fulfilled yet, [1][2][3][4][5] mainly because of the big challenge and difficulty to realize high-order MPE luminescence. Even for those materials exhibiting such MPE luminescence, the five-photon excited luminescence phenomena can be only observed in the dispersed solutions of either organic chromophore molecules or core-shell halide perovskite semiconductor nanocrystals (MAPbBr 3 /(OA) 2 PbBr 4 ) in order to diminish the aggregation-caused quenching (ACQ) while still with quite low multiphoton action cross-sections (MPACs), or have poor stability without any encapsulation approaches (The MPAC (ησ n ) is the product of photoluminescence quantum yield (PLQY, η) and multiphoton absorption cross-section (σ n ), the parameter to evaluate the multiphoton excited luminescence brightness). [6,7] The deficiency of bulky high-order MPE luminescence solid single crystals with low excitation threshold have further limited the exploration and implementation of such MPE materials into miniaturization and device, and thus their practical applications.Some porous materials such as mesoporous silica and porous alumina have been utilized to confine dye molecules and perovskite nanoparticles and thus to diminish the ACQ and to develop the solid-state luminescence. [4,[8][9][10][11] The emergence of a new type of porous materials, metal-organic frameworks (MOFs), has provided the significant promise to provide much better confinement for the potentially luminescent dye molecules and perovskite nanoparticles because of their more tunable pores/cages and specific sites to introduce strong recognitions. Indeed, we have recently realized a three-photon excited emissive material ZJU-68⊃DMASM through an exact match of a dye molecule with the pores of the metal-organic framework although high-order MPE luminescence solid single The development of the photostable higher-order multiphoton-excited (MPE) upconversion single microcrystalline material is fundamentally and technologically important, but very challenging. Here, up to five-photon excited luminescence in a host-guest metal-organic framework (MOF) and perovskite quantum dot (QD) hybrid single crystal ZJU-28⊃MAPbBr 3 is shown via an in situ growth approach. Such a MOF strategy not only results in a high QD loading concentration, but also significantly diminishes the aggregationcaused quenching (ACQ) effect, provides effective surface passivation, and greatly reduces the contact of the QDs with the external bad atmosphere due to the confinement effect and protection of the framework. These advantages make the resulting ZJU-28⊃MAPb...

A hybrid blue perovskite@metal–organic gel (MOG) nanocomposite: simultaneous improvement of luminescence and stability

“…Because of these shielding effects by the MOG matrix, the water molecules are unable to penetrate the MOG layer and cannot reach the perovskite NCs, leading to excellent stability in open air, water and under UV light. [22][23][24]54 Additionally, a variety of well-dened smooth and crack-free articial shapes and sculptures were successfully fabricated with these composites, without the addition of any external binder ( Fig. 3a and S42-S46, ESI †).…”

“…Encapsulation strategies have been considered as an efficient approach to enhance this optical property, as well as the chemical stability of perovskite NCs, and porous metal-organic frameworks (MOFs) are the latest addition, in this context. [22][23][24][25] However, the heterogeneous properties of MOFs are one of the key issues that restrict further utilization of perovskite-MOF nanocomposites in the form of thin lms or different workable structures. 26 In light of the growing interest in exible electronics, perovskite NCs embedded with so materials could offer high tolerance to structural deformation.…”

Intermarriage of Halide Perovskites and Metal‐Organic Framework Crystals

“…[17,18] Encapsulating in MOFs prevents the aggregation and coarsening of the perovskite quantum dots. [19] Thec omposite also enables mechanistic study on the effect of pore structure and pore chemical environment on the perovskite behaviour,f or example,t he encapsulation can modulate electron-hole recombination, [20] and afford synergistic photoluminescence functions similar to quantum dots. [21] Specific benefits of using MOF for perovskite composites are:…”

“…[17] 3) Spatial distribution of the guests:F or the post-synthetic loading of the precursor, because of the commonly high diffusion resistance of MOFs, it is anticipated that al arge number of MOF pores may remain unoccupied, or there may be aconcentration gradient from the surface to the centre of the MOF.Therefore,delicate activation of the MOF and control over the precursor loading are required, especially for single crystals of bulkier MOFs. [19] Figure 2. Schematic overview of the perovskite-MOF composite fabrication technique.…”

Metal Halide Perovskite@Metal‐Organic Framework Hybrids: Synthesis, Design, Properties, and Applications

“…Smart integration of MOFs with perovskites has been proven to control the agglomeration allows excellent features like high thermal stability, significant water resistance stable photoluminescence, excellent charge separation efficiency, and important gas capturing/activation ability. [66][67][68][69][70][71][72][73] Recently, a few strategies have been reported for synthesizing hybrid MOFs by encapsulating various perovskite halides (hybrids denoted as MHP@MOF), allowing optoelectronic and energy harvesting applications. This review offers a broad overview of the state-ofthe-art in MHP@MOF hybrids synthesis, along with the challenges, opportunities, and future perspectives.…”