J. Semicond. > 2022, Volume 43 > Issue 5 > 050201

RESEARCH HIGHLIGHTS

Domain controlling and defect passivation for efficient quasi-2D perovskite LEDs

Dezhong Zhang1, Chuanjiang Qin1, 2, and Liming Ding3,

+ Author Affiliations

 Corresponding author: Chuanjiang Qin, cjqin@ciac.ac.cn; Liming Ding, ding@nanoctr.cn

DOI: 10.1088/1674-4926/43/5/050201

PDF

Turn off MathJax

Metal halide perovskites have made rapid progress in photonic and optoelectronic applications since the first report of solid-state perovskite solar cells in 2012[1]. Perovskites feature superior luminescence properties beneficial for the application in light emitting diodes (LEDs), such as high photoluminescence quantum yields (PLQYs), narrow emission, and tunable bandgaps[2, 3]. Low-cost perovskite LEDs (PeLEDs) have attracted interests, causing fast enhancement of their performances, and demonstrating great potential in next-generation lighting and display applications.

Quasi-2D perovskites represent an important category of perovskites, with great success in light emission applications due to their unique and excellent optoelectronic properties. It is characterized through a sandwich structure that PbX6 octahedra sheets are packaged by large ammonium cations, forming a layered either Ruddlesden-Popper (RP) phase with formula of L2Sn–1PbnX3n+1, or Dion-Jacobson (DJ) phase with formula of LSn–1PbnX3n+1, where L is monovalent or divalent ammonium cation, S is small cation, X is halide anion, and n is the order of quasi-2D perovskite (the number of stacked PbX6 sheets). Quasi-2D perovskites with reduced dimension can construct self-organized multiple quantum-wells to induce both dielectric- and quantum-confinement effects, thus improving exciton binding energy over several hundred meV and enabling PLQYs up to 100%[4-6]. The emission behavior of quasi-2D perovskites is also determined by exciton recombination kinetics, and the management of singlet and triplet excitons in quasi-2D perovskites is fundamental for designing efficient PeLEDs and laser gain media[7]. In addition, there are efficient energy funnels from low-n value to high-n value domains in mixed-phase quasi-2D perovskite emitting layers, leading to accumulated excitons in the recombination centers, which is beneficial for high radiative recombination efficiency and PLQY even at low pump power densities[8].

Efforts have been devoted to designing and fabricating high-quality quasi-2D perovskite films for laser and LED applications. Qin et al. first reported stable room-temperature continuous photoinduced perovskite laser[9]. Meanwhile, extensive works on quasi-2D perovskites have been performed to improve the performance of PeLEDs, demonstrating highly efficient green devices with over 25% EQE, red and near-infrared devices over 20%, and blue devices over 10%, respectively[10-12]. Domain distribution controlling and defect passivation in quasi-2D perovskite emitting layers are the most effective strategies for quasi-2D PeLEDs.

Quasi-2D perovskite films feature a mixed phase rather than a single phase because the formation energies for different phases are similar. The solubility difference of precursor components and steric hindrance difference between cations cause a wide domain distribution, which may cause several problems. First, low-n value (n = 1 and 2) domains with reduced crystal size accompany with more traps, resulting in serious trap-induced nonradiative recombination. Second, though the energy transfer from low-n domains to adjacent high-n domains is faster than trapping, the energy loss still inevitably exists. At last, the higher-n (n > 10) domains tend to form free carriers and make nonradiative recombination, which also yields modest PLQY. It is important to narrow the distribution to avoid nonradiative recombination.

Zhang et al. made quasi-2D perovskite films with a narrow domain distribution by using two additives, ZrO2 nanoparticles (NPs) and cryptand[13]. ZrO2 NPs promote synchronous crystallization by facilitating the interaction between solvent and antisolvent, and cryptand complexing with Pb2+ retards the crystallization of high-n domains by forming an intermediate state, thus enhancing EQE of green PeLED from 16% to 21%. Narrowing domain distribution can also improve emission color purity and achieve spectra-stable blue devices. Yantara et al. reported that composition engineering through prudent selection of the cations coupled with rapid nucleation can result in a narrow domain distribution[14] (Fig. 1(b)). Methanesulfonate was used to reconstruct quasi-2D perovskite, yielding green PeLEDs with >20% EQE (Fig. 1(c))[15]. Ma et al. used a bifunctional additive, tris(4-fluorophenyl)phosphine oxide (TFPPO), to prepare quasi-2D perovskites with a monodispersed domain distribution[10]. The fluorine atoms make hydrogen bonding with organic cations, controlling their diffusion and suppressing the formation of low-n domains (Fig. 1(d)), and phosphine oxide moiety passivates grain boundaries via coordinating with the unsaturated sites. Green PeLEDs with an EQE of 25.6% were obtained.

Figure  1.  (Color online) (a) Competition between radiative recombination and nonradiative recombination for domains with different n. Reproduced with permission[13], Copyright 2021, Wiley. (b) The strategy to form intermediate domains for emissive quasi-2D perovskite films. Reproduced with permission[14], Copyright 2020, American Chemical Society. (c) Effect of MeS on domain distribution in quasi-2D perovskite films. Reproduced with permission[15], Copyright 2021, Springer Nature. (d) Domain distribution controlling by using TFPPO. Reproduced with permission[10], Copyright 2021, Springer Nature.

Inevitable defects and traps can easily form in polycrystalline perovskite films during crystallization in solution-processing methods. Compared with 3D perovskites, quasi-2D perovskites with reduced crystal size have higher defect densities. The charged defects can act as nonradiative recombination centers to decrease emission efficiency.

Halide anion vacancies in quasi-2D perovskites are usually shallow-level defects (at least for Br- or I-containing perovskites), which are not detrimental to device performance. Defects with deep trap states such as interstitial or anti-site defects are almost absent in perovskites since they have high formation energies. Coordination-unsaturated Pb ion can act as nonradiative recombination centers, which should be treated seriously during passivation[16, 17]. Understanding the effect of defects on device performance, and developing passivation strategies are critical for enhancing the performance of quasi-2D PeLEDs.

Passivators with X=O bond (X: P, C, S or other atoms) are effective to coordinate with Pb defects. Among them, the P=O:Pb dative bond showed a strong binding energy of 1.1 eV, avoiding nonradiative recombination caused by Pb defects[4]. Passivation agent with P=O such as trioctylphosphine oxide, triphenylphosphine oxide, as well as their derivatives all enhanced PLQY of quasi-2D perovskite films[10]. Meanwhile, Pb defects exposed at the edge of quasi-2D perovskite can also cause the instability. Photogenerated and electrically-injected carriers diffuse to perovskite edges and produce superoxide, causing rapid photodegradation (Fig. 2(a)). Quan et al. reported an edge-stabilization strategy of passivating exposed Pb defects by P=O bonds, which improved EQE and stability of quasi-2D PeLEDs[4]. C=O and C–O–C bonds also demonstrate outstanding Pb-defect passivation ability[6, 18]. Liu et al. developed a dual-additive strategy to prepare quasi-2D perovskite films with low defect density and high environmental stability by using 18-crown-6 and poly(ethylene glycol) methyl ether acrylate (MPEG-MAA) as additives (Fig. 2(b))[18]. The EQE of green PeLEDs reached 28.1%. 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) ionic liquid can also passivate Pb defects[19]. Spontaneously formed targeted distribution of the ionic additive well matches the defect site distribution (Fig. 2(c)). Novel passivators with more functions have been explored. Phosphonate-triphenylphosphine oxide with dual roles of passivating defects and enhancing carrier radiative recombination boosted EQE over 25%[20]. Phosphine oxide can enhance PLQY by passivating Pb defects, and phosphonate with strong electron affinity can accelerate carrier radiative recombination by capturing injected electrons (Fig. 2(d)). Defect passivation plays critical role to realize highly efficient PeLEDs.

Figure  2.  (Color online) (a) Degradation mechanisms and edge-stabilization strategy via P=O bonds. Reproduced with permission[4], Copyright 2020, Springer Nature. (b) Schematic illustration of crystal structure change and defect passivation by crown and MPEG-MAA. Reproduced with permission[18], Copyright 2021, Wiley. (c) Passivation mechanism of ionic liquid additive with C=N bond. Reproduced with permission[19], Copyright 2021, American Chemical Society. (d) PE-TPPO-modified PeLED. Reproduced with permission[20], Copyright 2022, Wiley.

In short, domain controlling and defect passivation are effective approaches to enhance EQE for quasi-2D PeLEDs. There are still challenges, such as highly efficient pure red and blue emission, long-term operation stability, and environmental safety.

We thank the National Natural Science Foundation of China (22075277, 22109156) and the China Postdoctoral Science Foundation (2021M703129) for financial support. L. Ding thanks the National Key Research and Development Program of China (2017YFA0206600) and the National Natural Science Foundation of China (51773045, 21772030, 51922032, and 21961160720) for financial support.



[1]
Kim H S, Lee C R, Im J H, et al. Lead iodide perovskite sensitized all-solid-state submicron thin film mesoscopic solar cell with efficiency exceeding 9%. Sci Rep, 2012, 2, 591 doi: 10.1038/srep00591
[2]
Wang N, Cheng L, Ge R, et al. Perovskite light-emitting diodes based on solution-processed self-organized multiple quantum wells. Nat Photonics, 2016, 10, 699 doi: 10.1038/nphoton.2016.185
[3]
Cho H, Jeong S H, Park M H, et al. Overcoming the electroluminescence efficiency limitations of perovskite light-emitting diodes. Science, 2015, 350, 1222 doi: 10.1126/science.aad1818
[4]
Quan L N, Ma D, Zhao Y, et al. Edge stabilization in reduced-dimensional perovskites. Nat Commun, 2020, 11, 170 doi: 10.1038/s41467-019-13944-2
[5]
Jiang Y, Cui M, Li S, et al. Reducing the impact of Auger recombination in quasi-2D perovskite light-emitting diodes. Nat Commun, 2021, 12, 336 doi: 10.1038/s41467-020-20555-9
[6]
Chu Z, Ye Q, Zhao Y, et al. Perovskite light-emitting diodes with external quantum efficiency exceeding 22% via small-molecule passivation. Adv Mater, 2021, 33, 2007169 doi: 10.1002/adma.202007169
[7]
Qin C, Matsushima T, Potscavage W J, et al. Triplet management for efficient perovskite light-emitting diodes. Nat Photonics, 2020, 14, 70 doi: 10.1038/s41566-019-0545-9
[8]
Yuan M, Quan L N, Comin R, et al. Perovskite energy funnels for efficient light-emitting diodes. Nat Nanotechnol, 2016, 11, 872 doi: 10.1038/nnano.2016.110
[9]
Qin C, Sandanayaka A S D, Zhao C, et al. Stable room-temperature continuous-wave lasing in quasi-2D perovskite films. Nature, 2020, 585, 53 doi: 10.1038/s41586-020-2621-1
[10]
Ma D, Lin K, Dong Y, et al. Distribution control enables efficient reduced-dimensional perovskite LEDs. Nature, 2021, 599, 594 doi: 10.1038/s41586-021-03997-z
[11]
Fang Z, Chen W, Shi Y, et al. Dual passivation of perovskite defects for light-emitting diodes with external quantum efficiency exceeding 20%. Adv Funct Mater, 2020, 30, 1909754 doi: 10.1002/adfm.201909754
[12]
Chu Z, Zhao Y, Ma F, et al. Large cation ethylammonium incorporated perovskite for efficient and spectra stable blue light-emitting diodes. Nat Commun, 2020, 11, 4165 doi: 10.1038/s41467-020-17943-6
[13]
Zhang D, Fu Y, Liu C, et al. Domain controlling by compound additive toward highly efficient quasi-2D perovskite light-emitting diodes. Adv Funct Mater, 2021, 31, 2103890 doi: 10.1002/adfm.202103890
[14]
Yantara N, Jamaludin N F, Febriansyah B, et al. Designing the perovskite structural landscape for efficient blue emission. ACS Energy Lett, 2020, 5, 1593 doi: 10.1021/acsenergylett.0c00559
[15]
Kong L, Zhang X, Li Y, et al. Smoothing the energy transfer pathway in quasi-2D perovskite films using methanesulfonate leads to highly efficient light-emitting devices. Nat Commun, 2021, 12, 1246 doi: 10.1038/s41467-021-21522-8
[16]
Akkerman Q A, Rainò G, Kovalenko M V, et al. Genesis, challenges and opportunities for colloidal lead halide perovskite nanocrystals. Nat Mater, 2018, 17, 394 doi: 10.1038/s41563-018-0018-4
[17]
Ye J, Byranvand M M, Martínez C O, et al. Defect passivation in lead-halide perovskite nanocrystals and thin films: toward efficient LEDs and solar cells. Angew Chem Int Ed, 2021, 133, 21804 doi: 10.1002/ange.202102360
[18]
Liu Z, Qiu W, Peng X, et al. Perovskite light-emitting diodes with EQE exceeding 28% through a synergetic dual-additive strategy for defect passivation and nanostructure regulation. Adv Mater, 2021, 33, 2103268 doi: 10.1002/adma.202103268
[19]
Peng X, Yang X, Liu D, et al. Targeted distribution of passivator for polycrystalline perovskite light-emitting diodes with high efficiency. ACS Energy Lett, 2021, 6, 4187 doi: 10.1021/acsenergylett.1c01753
[20]
Zhao C, Wu W, Zhan H, et al. Phosphonate/phosphine oxide dyad additive for efficient perovskite light-emitting diodes. Angew Chem Int Ed, 2022, e202117374 doi: 10.1002/anie.202117374
Fig. 1.  (Color online) (a) Competition between radiative recombination and nonradiative recombination for domains with different n. Reproduced with permission[13], Copyright 2021, Wiley. (b) The strategy to form intermediate domains for emissive quasi-2D perovskite films. Reproduced with permission[14], Copyright 2020, American Chemical Society. (c) Effect of MeS on domain distribution in quasi-2D perovskite films. Reproduced with permission[15], Copyright 2021, Springer Nature. (d) Domain distribution controlling by using TFPPO. Reproduced with permission[10], Copyright 2021, Springer Nature.

Fig. 2.  (Color online) (a) Degradation mechanisms and edge-stabilization strategy via P=O bonds. Reproduced with permission[4], Copyright 2020, Springer Nature. (b) Schematic illustration of crystal structure change and defect passivation by crown and MPEG-MAA. Reproduced with permission[18], Copyright 2021, Wiley. (c) Passivation mechanism of ionic liquid additive with C=N bond. Reproduced with permission[19], Copyright 2021, American Chemical Society. (d) PE-TPPO-modified PeLED. Reproduced with permission[20], Copyright 2022, Wiley.

[1]
Kim H S, Lee C R, Im J H, et al. Lead iodide perovskite sensitized all-solid-state submicron thin film mesoscopic solar cell with efficiency exceeding 9%. Sci Rep, 2012, 2, 591 doi: 10.1038/srep00591
[2]
Wang N, Cheng L, Ge R, et al. Perovskite light-emitting diodes based on solution-processed self-organized multiple quantum wells. Nat Photonics, 2016, 10, 699 doi: 10.1038/nphoton.2016.185
[3]
Cho H, Jeong S H, Park M H, et al. Overcoming the electroluminescence efficiency limitations of perovskite light-emitting diodes. Science, 2015, 350, 1222 doi: 10.1126/science.aad1818
[4]
Quan L N, Ma D, Zhao Y, et al. Edge stabilization in reduced-dimensional perovskites. Nat Commun, 2020, 11, 170 doi: 10.1038/s41467-019-13944-2
[5]
Jiang Y, Cui M, Li S, et al. Reducing the impact of Auger recombination in quasi-2D perovskite light-emitting diodes. Nat Commun, 2021, 12, 336 doi: 10.1038/s41467-020-20555-9
[6]
Chu Z, Ye Q, Zhao Y, et al. Perovskite light-emitting diodes with external quantum efficiency exceeding 22% via small-molecule passivation. Adv Mater, 2021, 33, 2007169 doi: 10.1002/adma.202007169
[7]
Qin C, Matsushima T, Potscavage W J, et al. Triplet management for efficient perovskite light-emitting diodes. Nat Photonics, 2020, 14, 70 doi: 10.1038/s41566-019-0545-9
[8]
Yuan M, Quan L N, Comin R, et al. Perovskite energy funnels for efficient light-emitting diodes. Nat Nanotechnol, 2016, 11, 872 doi: 10.1038/nnano.2016.110
[9]
Qin C, Sandanayaka A S D, Zhao C, et al. Stable room-temperature continuous-wave lasing in quasi-2D perovskite films. Nature, 2020, 585, 53 doi: 10.1038/s41586-020-2621-1
[10]
Ma D, Lin K, Dong Y, et al. Distribution control enables efficient reduced-dimensional perovskite LEDs. Nature, 2021, 599, 594 doi: 10.1038/s41586-021-03997-z
[11]
Fang Z, Chen W, Shi Y, et al. Dual passivation of perovskite defects for light-emitting diodes with external quantum efficiency exceeding 20%. Adv Funct Mater, 2020, 30, 1909754 doi: 10.1002/adfm.201909754
[12]
Chu Z, Zhao Y, Ma F, et al. Large cation ethylammonium incorporated perovskite for efficient and spectra stable blue light-emitting diodes. Nat Commun, 2020, 11, 4165 doi: 10.1038/s41467-020-17943-6
[13]
Zhang D, Fu Y, Liu C, et al. Domain controlling by compound additive toward highly efficient quasi-2D perovskite light-emitting diodes. Adv Funct Mater, 2021, 31, 2103890 doi: 10.1002/adfm.202103890
[14]
Yantara N, Jamaludin N F, Febriansyah B, et al. Designing the perovskite structural landscape for efficient blue emission. ACS Energy Lett, 2020, 5, 1593 doi: 10.1021/acsenergylett.0c00559
[15]
Kong L, Zhang X, Li Y, et al. Smoothing the energy transfer pathway in quasi-2D perovskite films using methanesulfonate leads to highly efficient light-emitting devices. Nat Commun, 2021, 12, 1246 doi: 10.1038/s41467-021-21522-8
[16]
Akkerman Q A, Rainò G, Kovalenko M V, et al. Genesis, challenges and opportunities for colloidal lead halide perovskite nanocrystals. Nat Mater, 2018, 17, 394 doi: 10.1038/s41563-018-0018-4
[17]
Ye J, Byranvand M M, Martínez C O, et al. Defect passivation in lead-halide perovskite nanocrystals and thin films: toward efficient LEDs and solar cells. Angew Chem Int Ed, 2021, 133, 21804 doi: 10.1002/ange.202102360
[18]
Liu Z, Qiu W, Peng X, et al. Perovskite light-emitting diodes with EQE exceeding 28% through a synergetic dual-additive strategy for defect passivation and nanostructure regulation. Adv Mater, 2021, 33, 2103268 doi: 10.1002/adma.202103268
[19]
Peng X, Yang X, Liu D, et al. Targeted distribution of passivator for polycrystalline perovskite light-emitting diodes with high efficiency. ACS Energy Lett, 2021, 6, 4187 doi: 10.1021/acsenergylett.1c01753
[20]
Zhao C, Wu W, Zhan H, et al. Phosphonate/phosphine oxide dyad additive for efficient perovskite light-emitting diodes. Angew Chem Int Ed, 2022, e202117374 doi: 10.1002/anie.202117374
  • Search

    Advanced Search >>

    GET CITATION

    shu

    Export: BibTex EndNote

    Article Metrics

    Article views: 1612 Times PDF downloads: 119 Times Cited by: 0 Times

    History

    Received: 09 March 2022 Revised: Online: Uncorrected proof: 14 March 2022Published: 01 May 2022

    Catalog

      Email This Article

      User name:
      Email:*请输入正确邮箱
      Code:*验证码错误
      Dezhong Zhang, Chuanjiang Qin, Liming Ding. Domain controlling and defect passivation for efficient quasi-2D perovskite LEDs[J]. Journal of Semiconductors, 2022, 43(5): 050201. doi: 10.1088/1674-4926/43/5/050201 ****D Z Zhang, C J Qin, L M Ding. Domain controlling and defect passivation for efficient quasi-2D perovskite LEDs[J]. J. Semicond, 2022, 43(5): 050201. doi: 10.1088/1674-4926/43/5/050201
      Citation:
      Dezhong Zhang, Chuanjiang Qin, Liming Ding. Domain controlling and defect passivation for efficient quasi-2D perovskite LEDs[J]. Journal of Semiconductors, 2022, 43(5): 050201. doi: 10.1088/1674-4926/43/5/050201 ****
      D Z Zhang, C J Qin, L M Ding. Domain controlling and defect passivation for efficient quasi-2D perovskite LEDs[J]. J. Semicond, 2022, 43(5): 050201. doi: 10.1088/1674-4926/43/5/050201

      Domain controlling and defect passivation for efficient quasi-2D perovskite LEDs

      DOI: 10.1088/1674-4926/43/5/050201
      More Information
      • Dezhong Zhang:got his BS in 2013 and PhD in 2019 from Jilin University. Then he joined Chuanjiang Qin Group at Changchun Institute of Applied Chemistry (CAS) as an assistant professor. His research focuses on perovskite solar cells and light-emitting diodes
      • Chuanjiang Qin:got his PhD from Changchun Institute of Applied Chemistry (CAS) in 2008. Then he worked as a postdoc at Hong Kong Baptist University and National Institute for Materials Science (Japan). Since 2014, he worked with Chihaya Adachi at Center for Organic Photonics and Electronics Research, Kyushu University as a research associate professor. In 2019, he joined Changchun Institute of Applied Chemistry as a full professor. His research focuses on perovskite materials and optoelectronic devices, including perovskite lasers, light-emitting diodes and solar cells
      • Liming Ding:got his PhD from University of Science and Technology of China (was a joint student at Changchun Institute of Applied Chemistry, CAS). He started his research on OSCs and PLEDs in Olle Ingans Lab in 1998. Later on, he worked at National Center for Polymer Research, Wright-Patterson Air Force Base and Argonne National Lab (USA). He joined Konarka as a Senior Scientist in 2008. In 2010, he joined National Center for Nanoscience and Technology as a full professor. His research focuses on innovative materials and devices. He is RSC Fellow, the nominator for Xplorer Prize, and the Associate Editor for Journal of Semiconductors
      • Corresponding author: cjqin@ciac.ac.cnding@nanoctr.cn
      • Received Date: 2022-03-09
        Available Online: 2022-04-27

      Catalog

        /

        DownLoad:  Full-Size Img  PowerPoint
        Return
        Return