Effective surface passivation on CsPbBr3 nanocrystals via post-treatment with aromatic carboxylic acid

Qiu, Jiaqing; Xue, Weinan; Wang, Wei; Li, Yan

doi:10.1016/j.dyepig.2021.109806

Cited by 15 publications

(12 citation statements)

References 40 publications

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“…The unwashed NC films exhibit a broad diffraction peak at 19.5°, and this peak goes away with the washing of the NCs. It was earlier attributed to the excess passivating ligands. − We found that the plasma treatment does not cause any major structural change or generate impurities like PbBr 2 , commonly found as a byproduct of degradation. , However, if we carefully observe the normalized diffraction pattern, the relative intensity ratio of the (220)/(112) peak increases. We deconvoluted the XRD patterns to quantify the relative intensity ratio of the (220)/(112) peak as shown in Figure S4a-d.…”

Section: Resultsmentioning

confidence: 77%

“…The photoluminesce properties of nanocrystals are strongly affected by the surface defects. − To probe if plasma treatment causes any changes in the surface defects of the CsPbBr 3 NCs, we performed time-correlated single-photon counting (TCSPC) measurements on the thin films without and with plasma treatment (Figure f). The biexponential decay fit (Figure S5) of TCSPC spectra suggested two different decay paths in all the CsPbBr 3 NC films.…”

Section: Resultsmentioning

confidence: 99%

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Plasma-Treated CsPbBr₃ Nanocrystal Films for Anticounterfeiting Applications

Rathod

Das

et al. 2022

ACS Appl. Nano Mater.

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Lead halide perovskite (LHP) nanocrystals (NCs) are considered propitious materials due to their extraordinary optoelectronic properties. Their poor ambient stability hinders their practical applications. Among the several approaches taken to enhance the ambient stability, plasma treatment is considered one of the best approaches because it does not hinder charge transport or reduce relative NC content while allowing easy and scalable processing. The plasma treatment increases the overall ambient stability of LHPs but at the cost of photoluminescence quantum yield (PLQY). We found that a short duration of the plasma treatment enhances the PL intensity by 30%, along with enhanced moisture stability. However, longer duration of plasma treatment decreases the photoluminescence (PL), and the NCs become hydrophilic. In this work, we report the underlying chemistry of stability enhancement during plasma treatment and how it affects the PL intensity. We performed Ar−O 2 plasma treatment on the CsPbBr 3 NCs thin films, which induces the cross-linking of the passivating ligand oleylamine that creates a stronger network of ligands, providing better encapsulation and higher PL intensity. A longer duration of plasma treatment results in oxidation of the passivating ligands in the presence of oxygen that eventually degrades the NCs. We created double-layer fluorescent security tags using the PL-stabilized NCs and as-synthesized NCs, having the same emission profile. The security pattern was created using the stabilized perovskite and masked with the assynthesized perovskite, which is relatively unstable and can be washed off under certain treatments.

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Section: Resultsmentioning

confidence: 77%

Section: Resultsmentioning

confidence: 99%

Plasma-Treated CsPbBr₃ Nanocrystal Films for Anticounterfeiting Applications

Rathod

Das

et al. 2022

ACS Appl. Nano Mater.

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“…General passivation strategies like doping, , heterostructure, ligand exchange, halide exchange, and core–shell formation have been carried out to achieve higher stability and performance. Few surface functional materials such as thiocyanate salt, aromatic carboxylic acid, metal halides, , ionic liquids, and organic compounds are researched upon to fill the vacancies and reduce the NRR via post-synthetic procedures. The PLQY improvement of CsPbBr 3 by Koscher et al went up to 100% by post-synthetic thiocyanate surface treatment.…”

Section: Introductionmentioning

confidence: 99%

Dual Vacancy Passivation in CsPbCl₃ Perovskite Nanocrystals: Implications on Optoelectronic Applications

Siddharthan

Thapa

et al. 2023

ACS Appl. Nano Mater.

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Despite numerous advantages over the traditional light absorbing materials, colloidal cesium lead halide (CsPbX 3 , X = Cl, Br, or I) perovskite nanocrystals (NCs) suffer from enormous defect density, leading to shorter lifetime of charge carriers and material instability. A large number of positively and negatively charged ionic defects are inevitably formed from crystallization via high temperature. Herein, we have studied a simple post-synthesis defect passivation of blue emitting CsPbCl 3 NCs using monovalent metal ion LiCl as a dual-passivating agent. The observed effect (on optical properties) went up by leaps and bounds. Photoluminescence (PL) quantum yield increases from 2.8 to 47.6%, while PL life time increases from 0.56 to 20.79 ns. Various other chloride salts (CaCl 2 , NH 2 Cl, KCl, and NaCl) and Li salts (LiBr and LiI) with different cation and anion combinations, respectively, did not give this effect. All these together with the enhanced overall stability of NCs suggest the synergistic effect of dual passivation and deep defect passivation that leads to significant suppression of non-radiative recombination. An X-ray photoelectron spectroscopy study also reveals that this simple strategy promotes simultaneous passivation of both defects (vacancies) formed from negatively (chlorine) and positively charged ions (lead) of CsPbCl 3. Theoretical study and experimental analysis in this work, together delivers a perceptive understanding of cationic and anionic vacancy healing by LiCl in CsPbCl 3 NCs, thus enhancing its utilization as efficient blue light emitters.

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“…As illustrated in Figures 2F and S8, the signals of Pb 2+ move to lower binding energies upon CPTA modification, confirming again that the CPTA molecule would diffuse into the PVK layer due to the solubility of CPTA in DMF (Figures S4 and S5) and hence the oxygen (O) atoms in CPTA donate its lone electron pair to the empty 6p orbital of Pb 2+ by coordination bond. [41,42] The strong chemical reactions between CPTA with WO 3 and PVK will passivate the defects at interface, which is conductive to suppress trap-assisted nonradiative recombination and beneficial for eliminating the light-soaking effect. [28,39] High-resolution synchrotron radiation photoelectron spectroscopy (HR-SRPES) was further carried out to evaluate the energy band levels [43,44] of the ETL and corresponding PVK films before and after CPTA treatment (Figure 3I,II).…”

Section: Resultsmentioning

confidence: 99%

Fullerene modification of WO₃ electron transport layer toward high‐efficiency MA‐free perovskite solar cells with eliminated light‐soaking effect

Xin

Cai

Zhang

et al. 2023

Interdisciplinary Materials

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In perovskite solar cells (PSCs), the light‐soaking effect, which means device performance changes obviously under continuous light illumination, is potentially harmful to loaded devices as well as accurately assessing their efficiency. Herein, chemically stable tungsten trioxide (WO3) with high electron mobility is used as electron transport material in methylamine (MA)‐free PSCs. However, the light‐soaking effect is observed apparently in our devices. A fullerene derivative, C60 pyrrolidine Tris‐acid (CPTA), is introduced to modify the interface between WO3 and perovskite (PVK) layers, which can bond with WO3 and PVK simultaneously, leading to the passivation of the defect and the suppression of trap‐assisted nonradiative recombination. What is more, the introduction of CPTA can enhance the built‐in electric field between WO3 and PVK layers, thereby facilitating the electron extraction and inhibiting the carrier accumulation at the interface. Consequently, the light‐soaking effect of WO3‐based PSCs has been eliminated, and the power conversion efficiency has been boosted from 17.4% for control device to 20.5% for WO3/CPTA‐based PSC with enhanced stability. This study gives guidance for the design of interfacial molecules to eliminate the light‐soaking effect.

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Effective surface passivation on CsPbBr3 nanocrystals via post-treatment with aromatic carboxylic acid

Cited by 15 publications

References 40 publications

Plasma-Treated CsPbBr₃ Nanocrystal Films for Anticounterfeiting Applications

Plasma-Treated CsPbBr₃ Nanocrystal Films for Anticounterfeiting Applications

Dual Vacancy Passivation in CsPbCl₃ Perovskite Nanocrystals: Implications on Optoelectronic Applications

Fullerene modification of WO₃ electron transport layer toward high‐efficiency MA‐free perovskite solar cells with eliminated light‐soaking effect

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Effective surface passivation on CsPbBr3 nanocrystals via post-treatment with aromatic carboxylic acid

Cited by 15 publications

References 40 publications

Plasma-Treated CsPbBr3 Nanocrystal Films for Anticounterfeiting Applications

Plasma-Treated CsPbBr3 Nanocrystal Films for Anticounterfeiting Applications

Dual Vacancy Passivation in CsPbCl3 Perovskite Nanocrystals: Implications on Optoelectronic Applications

Fullerene modification of WO3 electron transport layer toward high‐efficiency MA‐free perovskite solar cells with eliminated light‐soaking effect

Contact Info

Product

Resources

About

Plasma-Treated CsPbBr₃ Nanocrystal Films for Anticounterfeiting Applications

Plasma-Treated CsPbBr₃ Nanocrystal Films for Anticounterfeiting Applications

Dual Vacancy Passivation in CsPbCl₃ Perovskite Nanocrystals: Implications on Optoelectronic Applications

Fullerene modification of WO₃ electron transport layer toward high‐efficiency MA‐free perovskite solar cells with eliminated light‐soaking effect