A carrier density dependent diffusion coefficient, recombination rate and diffusion length in MAPbI<sub>3</sub> and MAPbBr<sub>3</sub> crystals measured under one- and two-photon excitations

Ščajev, Patrik; Miasojedovas, S.; Juršėnas, Saulius

doi:10.1039/d0tc02283g

Cited by 30 publications

(16 citation statements)

References 70 publications

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“…An MRC/supertrap mechanism is much less sensitive to the size, it requires the crystal to be smaller than the charge carrier diffusion length, which for perovskites is of the order of 1000 nm. [ 60–62 ] While for small nanocrystals (QDs) probably both mechanisms are relevant, [ 10,63 ] upon increasing the size, the contribution of the Auger mechanism goes down. Therefore, large crystals without local energy funnels (emitting sites) cannot blink by the Auger mechanism and, therefore also cannot possess antibunching while an MRC/supertrap mechanism can still give PL blinking.…”

Section: Discussionmentioning

confidence: 99%

Lack of Photon Antibunching Supports Supertrap Model of Photoluminescence Blinking in Perovskite Sub‐Micrometer Crystals

Eremchev

Tarasevich

et al. 2020

Advanced Optical Materials

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Antibunching effect is typically observed in individual systems possessing photoluminescence (PL) blinking and vice versa. Contrary to this common perception, absence of antibunching in strongly blinking methyl ammonium led tri‐iodide (MAPbI3) perovskite crystals of sizes from tens to hundreds of nanometers regardless of the excitation power density is observed. Antibunching effect does not appear even when photon statistics are analyzed for bright and intermediate PL intensity levels independently. This shows that there is no directional energy funneling and accumulation of charge carriers in the small local regions in MAPbI3 crystals where an Auger recombination can potentially suppress the simultaneous emission of two photons. This result allows for the exclusion of the PL blinking mechanism based on the idea of emitting sites previously hypothesized for perovskites. Therefore, the model of PL blinking in perovskite crystals based on the presence of a metastable non‐radiative recombination center (the supertrap) is the only one proposed so far which explains blinking without conflicting with the absence of photon correlations.

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Section: Discussionmentioning

confidence: 99%

Lack of Photon Antibunching Supports Supertrap Model of Photoluminescence Blinking in Perovskite Sub‐Micrometer Crystals

Eremchev

Tarasevich

et al. 2020

Advanced Optical Materials

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“…The photocurrent profiles exhibited a peaked, Lorentzian-type shape, consistent with eq above. These profiles fit well to eq (Figure b), yielding a diffusion length of 2.9 μm, a value which is within the range of previously reported values for MAPbBr 3 obtained via bulk optical measurements , or time-resolved microscopy . This diffusion length determined through CG-TC measurements is consistent with the SECCM results presented in Figure , where lower photocurrents were observed in regions within ∼3 μm of defects on the crystal surface.…”

Section: Resultsmentioning

confidence: 99%

Facet-Dependent Photoelectrochemistry on Single Crystal Organic–Inorganic Halide Perovskite Electrodes

Saha

Rahman

Tolbert

et al. 2023

Chemical & Biomedical Imaging

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Organometallic halide perovskites have garnered significant attention in various fields of material science, particularly solar energy conversion, due to their desirable optoelectronic properties and compatibility with scalable fabrication techniques. It is often unclear, however, how carrier generation and transport within complex polycrystalline films are influenced by variations in local structure. Elucidating how distinct structural motifs within these heterogeneous systems affect behavior could help guide the continued improvement of perovskite-based solar cells. Here, we present studies applying scanning electron microscopy (SECCM) to map solar energy harvesting within well-defined model systems of organometallic halide perovskites. Methylammonium lead bromide (MAPbBr 3 ) single crystals were prepared via a low-temperature solution-based route, and their photoelectrochemical properties were mapped via SECCM using p-benzoquinone (BQ) in dichloromethane as a redox mediator. Correlated SECCM mapping and electron microscopy studies enabled facet-to-facet variations in photoelectrochemical performance to be revealed and carrier transport lengths to be evaluated. The photoelectrochemical behavior observed within individual single crystals was quite heterogeneous, attributable to local variations in crystal structure/ orientations, intrafacet junctions, and the presence of other structural defects. These observations underscore the significance of controlling the microstructure of single perovskite crystals, presenting a promising avenue for further enhancement of perovskitebased solar cells.

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“…The PL signal was reduced while being measured in the transmission configuration due to light scattering in nonwoven material. However, the up-conversion PL was observable with a naked eye, as shown in Figure 1 f. The PL peak dependency on the excitation fluence in the log-log scale demonstrated a 1.9 slope close to 2, which was typical for a two-photon process [ 45 , 46 , 47 ]. The up-conversion PL did not demonstrate degradation in time during the measurement, which can be attributed to the low light-matter interaction intensity of the two-photon process (absorption of two photons is a very rare event compared to UV light absorption).…”

Section: Resultsmentioning

confidence: 99%

Recrystallization of CsPbBr3 Nanoparticles in Fluoropolymer Nonwoven Mats for Down- and Up-Conversion of Light

et al. 2021

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Inorganic halides perovskite CsPbX3 (X = Cl, Br, and I or mixed halide systems Cl/Br and Br/I) nanoparticles are efficient light-conversion objects that have attracted significant attention due to their broadband tunability over the entire visible spectral range of 410–700 nm and high quantum yield of up to 95%. Here, we demonstrate a new method of recrystallization of CsPbBr3 nanoparticles inside the electrospun fluoropolymer fibers. We have synthesized nonwoven tetrafluoroethylene mats embedding CsPbBr3 nanoparticles using inexpensive commercial precursors and syringe electrospinning equipment. The fabricated nonwoven mat samples demonstrated both down-conversion of UV light to 506 nm and up-conversion of IR femtosecond laser radiation to 513 nm green photoluminescence characterized by narrow emission line-widths of 35 nm. Nanoparticle formation inside nonwoven fibers was confirmed by TEM imaging and water stability tests controlled by fluorimetry measurements. The combination of enhanced optical properties of CsPbBr3 nanoparticles and mechanical stability and environmental robustness of highly deformable nonwoven fluoropolymer mats is appealing for flexible optoelectronic applications, while the industry-friendly fabrication method is attractive for commercial implementations.

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A carrier density dependent diffusion coefficient, recombination rate and diffusion length in MAPbI₃ and MAPbBr₃ crystals measured under one- and two-photon excitations

Abstract:
Recombination, diffusion rates and diffusion length in MAPbI₃ and MAPBr₃ crystals in a wide carrier density range: experiment and theory.

Cited by 30 publications

References 70 publications

Lack of Photon Antibunching Supports Supertrap Model of Photoluminescence Blinking in Perovskite Sub‐Micrometer Crystals

Lack of Photon Antibunching Supports Supertrap Model of Photoluminescence Blinking in Perovskite Sub‐Micrometer Crystals

Facet-Dependent Photoelectrochemistry on Single Crystal Organic–Inorganic Halide Perovskite Electrodes

Recrystallization of CsPbBr3 Nanoparticles in Fluoropolymer Nonwoven Mats for Down- and Up-Conversion of Light

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A carrier density dependent diffusion coefficient, recombination rate and diffusion length in MAPbI3 and MAPbBr3 crystals measured under one- and two-photon excitations

Abstract: Recombination, diffusion rates and diffusion length in MAPbI3 and MAPBr3 crystals in a wide carrier density range: experiment and theory.

Cited by 30 publications

References 70 publications

Lack of Photon Antibunching Supports Supertrap Model of Photoluminescence Blinking in Perovskite Sub‐Micrometer Crystals

Lack of Photon Antibunching Supports Supertrap Model of Photoluminescence Blinking in Perovskite Sub‐Micrometer Crystals

Facet-Dependent Photoelectrochemistry on Single Crystal Organic–Inorganic Halide Perovskite Electrodes

Recrystallization of CsPbBr3 Nanoparticles in Fluoropolymer Nonwoven Mats for Down- and Up-Conversion of Light

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Product

Resources

About

A carrier density dependent diffusion coefficient, recombination rate and diffusion length in MAPbI₃ and MAPbBr₃ crystals measured under one- and two-photon excitations

Abstract:
Recombination, diffusion rates and diffusion length in MAPbI₃ and MAPBr₃ crystals in a wide carrier density range: experiment and theory.