Enhanced aqueous stability and radiative-charge-transfer of CsPbBr3/Ag2S perovskite nanocrystal hybrids

https://doi.org/10.1016/j.jelechem.2020.113835Get rights and content

Highlights

  • CsPbBr3-Ag2S hybrids can exhibit enhanced aqueous stability and radiative-charge-transfer than CsPbBr3 PNCs.

  • Charges injected onto Ag2S segment of CsPbBr3/Ag2S hybrids can be transferred to CsPbBr3 segment.

  • PL and ECL of CsPbBr3/Ag2S hybrids only occur within CsPbBr3 segment.

Abstract

A convenient strategy to enhance the aqueous stability and radiative-charge-transfer of perovskite nanocrystals (PNCs) is developed via hybriding CsPbBr3 PNCs with Ag2S nanoparticles, which is conducted by directly decomposing silver diethyldithiocarbamate in CsPbBr3 PNCs crude. The obtained CsPbBr3-Ag2S hybrids are aqueous stable, and exhibit obviously enhanced aqueous photoluminescence (PL) with a quantum yield up to 82% in pure water as well as boosted electrochemical response for charge injection and 9-fold enhanced electrochemiluminescence (ECL) than CsPbBr3 PNCs in aqueous electrolyte. Both PL and ECL spectra of CsPbBr3-Ag2S hybrids are almost identical to the PL spectrum of CsPbBr3 PNCs, indicating radiative-charge-transfer within CsPbBr3-Ag2S hybrids only occurs in CsPbBr3 segment. Annihilation ECL demonstrates that all the charges injected onto CsPbBr3-Ag2S hybrids at the redox potentials of Ag2S segment can be efficiently transferred into CsPbBr3 segment to enhance radiative-charge-transfer. This strategy is promising for the application of PNCs as well as the developing of novel electrochemiluminophores.

Introduction

CsPbX3 (X = Cl, Br, I) perovskite nanocrystals (PNCs) are promising candidates for solar cells [[1], [2], [3], [4]], light emitting diodes [[5], [6], [7], [8]], photodetectors [9], and other optoelectronic devices [10,11], due to their desirable optical characteristics of color tunability [5,12], monochromatic photoluminescence (PL) emission [13,14], and high PL quantum yield (QY) [15,16]. Although PNCs arouse tremendous interests in scientific communities [17], investigation and application of them are still seriously hindered by their poor stability to moisture [7,18]. Several strategies have been tested to improve the aqueous stability of PNCs. One is to isolate PNCs from moisture via coating them with inert and/or hydrophobic materials [19,20], such as silica [21,22] and polystyrene [23,24]. For example, embedding CsPbX3 PNCs in polystyrene microspheres can improve their aqueous stability for cell imaging [24]. Another approach is to increase the intrinsic stability of PNCs via doping heteroatoms [25,26], halide-rich syntheses [27,28], surface functionalization [29,30], and/or changing ligands [31,32]. Passivating CsPbBr3 PNCs surface with the silver complex can lead to enhanced photostability of CsPbBr3 PNCs [33]. Balakrishnan demonstrates that forming Au nanocrystals (NCs) on CsPbBr3 PNCs can bring out stable perovskite hybrids under ambient conditions [34], which opens a way towards stable PNCs via forming various hybrid nanostructures, such as CsPbBr3@Ag, CsPbBr3/ZnS, and CsPbBr3/PbSe [[35], [36], [37]]. Unfortunately, the stability of these PNCs hybrids against polar solvents is still intrinsically fragile [38].

Herein, a convenient and effective strategy for improved aqueous stability and radiative-charge-transfer of PNCs is proposed by anchoring Ag2S nanoparticles (NPs) onto CsPbBr3 PNCs via directly decomposing silver diethyldithiocarbamate (Ag(DDTC)) in the CsPbBr3 PNCs crude. The obtained CsPbBr3-Ag2S nano-heterostructures, i.e. PNCs hybrids, not only demonstrates dramatically enhanced aqueous stability up to 1 month and PLQY up to 82% in pure water, but also exhibits promoted electrochemical charge-injection response upon the assistant of Ag2S and boosted monochromatic electrochemiluminescence (ECL) than CsPbBr3 PNCs in aqueous electrolyte, as a result of the stronger electrochemical response of Ag2S than CsPbBr3 as well as the enhanced radiative charge recombination induced by transferring the charges injected onto the Ag2S segment into the CsPbBr3 segment. These findings promise both monochromatic electrochemiluminophores and perovskite heterostructures for stable and tunable optoelectronic devices [37,39].

Section snippets

Materials

All chemicals and reagents are of analytical grade or better, all aqueous solutions are prepared with DDW. Cesium carbonate (Cs2CO3, 99%), lead bromide (PbBr2, 99%), 1-octadecene (ODE, C18H36, 90%), oleic acid (OA, 90%), oleylamine (OAL, C18H37N, 80–90%), hexane (C6H14, 97%), and TPrA (>99%) are purchased from Aladdin. Silver diethyldithiocarbamate (Ag(DDTC), 99%) is obtained from Shanghai Titan Technology Co., Ltd. (Shanghai, China). Air-free supporting electrolyte solution is achieved by

Characterization of CsPbBr3 PNCs and CsPbBr3-Ag2S hybrids

As shown in Fig. 1a, both pure CsPbBr3 PNCs and CsPbBr3-Ag2S hybrids in hexane exhibit similar absorption nature with the first excitonic peak around 504 nm and high monochromatic PL nature with maximum emission around 515 nm and full width at half-maximum (FWHM) of 21 nm respectively. The formation of CsPbBr3-Ag2S hybrids via decomposing Ag(DDTC) in CsPbBr3 PNCs crude demonstrates negligible influence on the excited states for PL of CsPbBr3 PNCs. PLQY of CsPbBr3 PNCs and CsPbBr3-Ag2S hybrids

Conclusions

Hybriding CsPbBr3 PNCs with small bandgap Ag2S NPs can be conveniently achieved and bring out promising CsPbBr3-Ag2S hybrids with improved aqueous stability and radiative charge transfer for both PL and ECL. The electrons and/or holes injected onto the Ag2S segment of CsPbBr3-Ag2S hybrids can be transferred into the counterpart CsPbBr3 segment for enhanced radiative charge transfer occurred within the CsPbBr3 segment via some ways. ECL transient demonstrates that merely injecting holes onto

CRediT authorship contribution statement

Kena Fu:Conceptualization, Investigation, Writing - original draft.Yupeng He:Investigation, Formal analysis.Bin Zhang:Supervision.Xuwen Gao:Validation, Formal analysis.Guizheng Zou:Writing - original draft, Writing - review & editing, Resources.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

This project was supported by the National Natural Science Foundation of China (Grant No. 21427808), and the Fundamental Research Funds of Shandong University (2018JC017).

References (48)

  • H. Huang et al.

    Water resistant CsPbX3 nanocrystals coated with polyhedral oligomeric silsesquioxane and their use as solid state luminophores in all-perovskite white light-emitting devices

    Chem. Sci.

    (2016)
  • I. Jeon et al.

    Lithium-ion endohedral fullerene (Li+@C60) dopants in stable perovskite solar cells induce instant doping and anti-oxidation

    Angew. Chem. Int. Ed.

    (2018)
  • N. Wang et al.

    Perovskite-based nanocrystals: synthesis and applications beyond solar cells

    Small Meth

    (2018)
  • M. Saliba et al.

    Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency

    Energy Environ. Sci.

    (2016)
  • M. Liu et al.

    Lattice anchoring stabilizes solution-processed semiconductors

    Nature

    (2019)
  • A. Swarnkar et al.

    Colloidal CsPbBr3 perovskite nanocrystals: luminescence beyond traditional quantum dots

    Angew. Chem. Int. Ed.

    (2015)
  • G. Li et al.

    Highly efficient perovskite nanocrystal light-emitting diodes enabled by a universal crosslinking method

    Adv. Mater.

    (2016)
  • H. Cho et al.

    Improving the stability of metal halide perovskite materials and light-emitting diodes

    Adv. Mater.

    (2018)
  • J. Li et al.

    50-fold EQE improvement up to 6.27% of solution-processed all-inorganic perovskite CsPbBr3 QLEDs via surface ligand density control

    Adv. Mater.

    (2017)
  • T.L. Doane et al.

    Using perovskite nanoparticles as halide reservoirs in catalysis and as spectrochemical probes of ions in solution

    ACS Nano

    (2016)
  • J. Song et al.

    Monolayer and few-layer all-inorganic perovskites as a new family of two-dimensional semiconductors for printable optoelectronic devices

    Adv. Mater.

    (2016)
  • Y. Wang et al.

    Synergies of electrochemical metallization and valance change in all-inorganic perovskite quantum dots for resistive switching

    Adv. Mater.

    (2018)
  • J. Song et al.

    Quantum dot light-emitting diodes based on inorganic perovskite cesium lead halides (CsPbX3)

    Adv. Mater.

    (2015)
  • S. Yakunin et al.

    Low-threshold amplified spontaneous emission and lasing from colloidal nanocrystals of caesium lead halide perovskites

    Nat. Commun.

    (2015)
  • L. Protesescu et al.

    Nanocrystals of cesium lead halide perovskites (CsPbX3, X = Cl, Br, and I): novel optoelectronic materials showing bright emission with wide color gamut

    Nano Lett.

    (2015)
  • Y. Tong et al.

    Highly luminescent cesium lead halide perovskite nanocrystals with tunable composition and thickness by utrasonication

    Angew. Chem. Int. Ed.

    (2016)
  • Y. Bekenstein et al.

    Highly luminescent colloidal nanoplates of perovskite cesium lead halide and their oriented assemblies

    J. Am. Chem. Soc.

    (2015)
  • X. Li et al.

    CsPbX3 quantum dots for lighting and displays: room-temperature synthesis, photoluminescence superiorities, underlying origins and white light-emitting diodes

    Adv. Funct. Mat.

    (2016)
  • N. Aristidou et al.

    Fast oxygen diffusion and iodide defects mediate oxygen-induced degradation of perovskite solar cells

    Nat. Commun.

    (2017)
  • H.-C. Wang et al.

    Mesoporous silica particles integrated with all-inorganic CsPbBr3 perovskite quantum-dot nanocomposites (MP-PQDs) with high stability and wide color gamut used for backlight display

    Angew. Chem. Int. Ed.

    (2016)
  • F. Zhang et al.

    Silica coating enhances the stability of inorganic perovskite nanocrystals for efficient and stable down-conversion in white light-emitting devices

    Nanoscale

    (2018)
  • S. Huang et al.

    Enhancing the stability of CH3NH3PbBr3 quantum dots by embedding in silica spheres derived from tetramethyl orthosilicate in “waterless” toluene

    J. Am. Chem. Soc.

    (2016)
  • Y. Cai et al.

    Improved stability of CsPbBr3 perovskite quantum dots achieved by suppressing interligand proton transfer and applying a polystyrene coating

    Nanoscale

    (2018)
  • H. Zhang et al.

    Embedding perovskite nanocrystals into a polymer matrix for tunable luminescence probes in cell imaging

    Adv. Funct. Mat.

    (2017)
  • Cited by (0)

    View full text