A Multifunctional Self‐Assembled Monolayer for Highly Luminescent Pure‐Blue Quasi‐2D Perovskite Light‐Emitting Diodes

Quasi‐2D perovskite materials have promise to unlock the full potential of blue perovskite light‐emitting diodes (PeLEDs). However, the efficiency of blue emissive PeLEDs still lags behind the green‐ and red‐emitting counterparts. Here, a multifunctional passivating molecule of (2‐(3,6‐dichloro‐9H‐carbazol‐9‐yl)ethyl)phosphonic acid (36ClCzEPA) that can form a self‐assembled monolayer (SAM) on the indium tin oxide (ITO) electrode is reported. The 36ClCzEPA SAM facilitates hole injection by increasing the work function of ITO through the strong interfacial dipole layer formation at the interface between the perovskite emitter and the ITO electrode. Moreover, it allows a pure‐blue emission and reduces the exciton quenching of luminescence in the perovskite emitter considerably because of its neutral nature, compared to the commonly used acidic PEDOT:PSS. Furthermore, chlorine atoms in the 36ClCzEPA promote well‐ordered crystalline 2D perovskite phases and decrease interfacial trap‐assisted deactivation channels by interfacial passivation. These beneficial characteristics of the 36ClCzEPA SAM yield the excellent luminescence property of PeLEDs with a maximum luminance of 1253 cd m−2 and a peak external quantum efficiency of 4.80% at 473 nm. This work demonstrates that a well‐designed molecule forming an interfacial SAM can be an important component for enhancing the luminescence property of pure‐blue PeLEDs.

[1]  R. Chen,et al.  High-Performance Blue Quasi-2D Perovskite Light-Emitting Diodes via Balanced Carrier Confinement and Transfer , 2022, Nano-Micro Letters.

[2]  Moritz H. Futscher,et al.  Reduced Barrier for Ion Migration in Mixed-Halide Perovskites , 2021, ACS applied energy materials.

[3]  Hong‐Bin Yao,et al.  High Color Purity and Efficient Green Light-Emitting Diode Using Perovskite Nanocrystals with the Size Overly Exceeding Bohr Exciton Diameter. , 2021, Journal of the American Chemical Society.

[4]  Andrew H. Proppe,et al.  Distribution control enables efficient reduced-dimensional perovskite LEDs , 2021, Nature.

[5]  R. Friend,et al.  Efficient and Spectrally Stable Blue Perovskite Light‐Emitting Diodes Employing a Cationic π‐Conjugated Polymer , 2021, Advanced materials.

[6]  Zhiqun Lin,et al.  Robust Molecular Dipole-Enabled Defect Passivation and Control of Energy Level Alignment for High-Efficiency Perovskite Solar Cells. , 2021, Angewandte Chemie.

[7]  Y. Qi,et al.  Interfacial toughening with self-assembled monolayers enhances perovskite solar cell reliability , 2021, Science.

[8]  T. Anthopoulos,et al.  18.4% Organic Solar Cells Using a High Ionization Energy Self-Assembled Monolayer as Hole Extraction Interlayer. , 2021, ChemSusChem.

[9]  Cathy Y. Wong,et al.  Ligand-engineered bandgap stability in mixed-halide perovskite LEDs , 2021, Nature.

[10]  R. Friend,et al.  Comprehensive defect suppression in perovskite nanocrystals for high-efficiency light-emitting diodes , 2021 .

[11]  M. Nazeeruddin,et al.  Applications of Self‐Assembled Monolayers for Perovskite Solar Cells Interface Engineering to Address Efficiency and Stability , 2020, Advanced Energy Materials.

[12]  S. Kwak,et al.  Sky Blue-Emissive Perovskite Light-Emitting Diodes: Crystal Growth and Interfacial Control Using Conjugated Polyelectrolytes as Hole-Transporting Layer. , 2020, ACS nano.

[13]  Rawad K. Hallani,et al.  Self-Assembled Monolayer Enables Hole Transport Layer-Free Organic Solar Cells with 18% Efficiency and Improved Operational Stability , 2020 .

[14]  Jingshan Luo,et al.  Toward Efficient and Stable Perovskite Solar Cells: Choosing Appropriate Passivator to Specific Defects , 2020, Solar RRL.

[15]  X. W. Sun,et al.  Simultaneous Low-Order Phase Suppression and Defect Passivation for Efficient and Stable Blue Light-Emitting Diodes , 2020 .

[16]  S. Zakeeruddin,et al.  Compositional and Interface Engineering of Organic-Inorganic Lead Halide Perovskite Solar Cells , 2020, iScience.

[17]  Jin Young Kim,et al.  Functionalized PFN-X (X = Cl, Br, I) for Balanced Charge Carriers of Highly Efficient Blue Light-Emitting Diodes. , 2020, ACS applied materials & interfaces.

[18]  M. Baranowski,et al.  Revealing Excitonic Phonon Coupling in(PE)2(MA)n-1PbnI3n+12D Layered Perovskites. , 2020, The journal of physical chemistry letters.

[19]  Zhenghong Lu,et al.  Chlorine Vacancy Passivation in Mixed Halide Perovskite Quantum Dots by Organic Pseudohalides Enables Efficient Rec. 2020 Blue Light-Emitting Diodes , 2020, ACS Energy Letters.

[20]  Jianbin Xu,et al.  An Interlayer with Strong Pb-Cl Bond Delivers Ultraviolet-Filter-Free, Efficient, and Photostable Perovskite Solar Cells , 2019, iScience.

[21]  Dawei Di,et al.  Efficient blue light-emitting diodes based on quantum-confined bromide perovskite nanostructures , 2019, Nature Photonics.

[22]  Su Seok Choi,et al.  Conjugated Polyelectrolytes as Multifunctional Passivating and Hole‐Transporting Layers for Efficient Perovskite Light‐Emitting Diodes , 2019, Advanced materials.

[23]  K. Uvdal,et al.  Rational molecular passivation for high-performance perovskite light-emitting diodes , 2019, Nature Photonics.

[24]  Christoph Wolf,et al.  Fine Control of Perovskite Crystallization and Reducing Luminescence Quenching Using Self‐Doped Polyaniline Hole Injection Layer for Efficient Perovskite Light‐Emitting Diodes , 2018, Advanced Functional Materials.

[25]  K. Lee,et al.  Reversible, Full-Color Luminescence by Post-treatment of Perovskite Nanocrystals , 2018, Joule.

[26]  Andrew H. Proppe,et al.  Compositional and orientational control in metal halide perovskites of reduced dimensionality , 2018, Nature Materials.

[27]  Liang Gao,et al.  Color-stable highly luminescent sky-blue perovskite light-emitting diodes , 2018, Nature Communications.

[28]  Q. Quan,et al.  Reducing Architecture Limitations for Efficient Blue Perovskite Light‐Emitting Diodes , 2018, Advanced materials.

[29]  Cherie R. Kagan,et al.  Electrons, Excitons, and Phonons in Two-Dimensional Hybrid Perovskites: Connecting Structural, Optical, and Electronic Properties. , 2018, The journal of physical chemistry letters.

[30]  S. Barlow,et al.  Electrode Work Function Engineering with Phosphonic Acid Monolayers and Molecular Acceptors: Charge Redistribution Mechanisms , 2018 .

[31]  R. Friend,et al.  Highly Efficient Light-Emitting Diodes of Colloidal Metal-Halide Perovskite Nanocrystals beyond Quantum Size. , 2017, ACS nano.

[32]  Rachel C. Kurchin,et al.  Searching for “Defect-Tolerant” Photovoltaic Materials: Combined Theoretical and Experimental Screening , 2017 .

[33]  Lin-wang Wang,et al.  High Defect Tolerance in Lead Halide Perovskite CsPbBr3. , 2017, The journal of physical chemistry letters.

[34]  Oleksandr Voznyy,et al.  Perovskite energy funnels for efficient light-emitting diodes. , 2016, Nature nanotechnology.

[35]  Himchan Cho,et al.  Metal halide perovskite light emitters , 2016, Proceedings of the National Academy of Sciences.

[36]  Baicheng Zhang,et al.  External Heavy-Atom Effect via Orbital Interactions Revealed by Single-Crystal X-ray Diffraction. , 2016, The journal of physical chemistry. A.

[37]  Sergei Tretiak,et al.  High-efficiency two-dimensional Ruddlesden–Popper perovskite solar cells , 2016, Nature.

[38]  Edward H. Sargent,et al.  Perovskite photonic sources , 2016, Nature Photonics.

[39]  K. Handrup,et al.  An Experimental Investigation of the Adsorption of a Phosphonic Acid on the Anatase TiO2(101) Surface , 2016 .

[40]  Richard H. Friend,et al.  Overcoming the electroluminescence efficiency limitations of perovskite light-emitting diodes , 2015, Science.

[41]  Christopher H. Hendon,et al.  Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, and I): Novel Optoelectronic Materials Showing Bright Emission with Wide Color Gamut , 2015, Nano letters.

[42]  Felix Deschler,et al.  Bright light-emitting diodes based on organometal halide perovskite. , 2014, Nature nanotechnology.

[43]  Nigel J. Alley,et al.  Stable organic photovoltaics using Ag thin film anodes , 2012 .

[44]  Tae-Woo Lee,et al.  Self‐Organized Gradient Hole Injection to Improve the Performance of Polymer Electroluminescent Devices , 2007 .