Spontaneous Silver Doping and Surface Passivation of CsPbI3 Perovskite Active Layer Enable Light-Emitting Devices with an External Quantum Efficiency of 11.2.

Lead halide perovskite nanocrystals are currently under intense investigation as components of solution-processed light-emitting devices (LEDs). We demonstrate LEDs based on Ag doped-passivated CsPbI3 perovskite nanocrystals with external quantum efficiency of 11.2% and an improved stability. Ag and trilayer MoO3/Au/MoO3 structure were used as cathode and anode, respectively, which reduce the electron injection barrier and ensure the high transparency and low resistance of the anode. Silver ions diffuse into perovskite film from the Ag electrode, as confirmed by the elemental mapping, the presence of Ag 3d peaks in the X-ray photoelectron spectrum, and the peak shift in the X-ray diffraction patterns of CsPbI3. In addition to doping, silver ions play the beneficial role of passivating surface defect states of CsPbI3 nanocrystals, which results in increased photoluminescence quantum yield, elongated emission lifetime, and improved stability of perovskite films.

[1]  Xueming Li,et al.  Organolead Halide Perovskite Nanocrystals: Branched Capping Ligands Control Crystal Size and Stability. , 2016, Angewandte Chemie.

[2]  Jing Cao,et al.  Synthesis of novel Z-scheme AgI/Ag/AgBr composite with enhanced visible light photocatalytic activity , 2012 .

[3]  Manas R. Parida,et al.  Engineering Interfacial Charge Transfer in CsPbBr3 Perovskite Nanocrystals by Heterovalent Doping. , 2017, Journal of the American Chemical Society.

[4]  Wasim J. Mir,et al.  Can B-Site Doping or Alloying Improve Thermal- and Phase-Stability of All-Inorganic CsPbX3 (X = Cl, Br, I) Perovskites? , 2018 .

[5]  Ashley R. Marshall,et al.  Quantum dot–induced phase stabilization of α-CsPbI3 perovskite for high-efficiency photovoltaics , 2016, Science.

[6]  Yuya Takeda,et al.  High-Efficiency Perovskite Quantum-Dot Light-Emitting Devices by Effective Washing Process and Interfacial Energy Level Alignment. , 2017, ACS applied materials & interfaces.

[7]  R. Friend,et al.  Amine-Based Passivating Materials for Enhanced Optical Properties and Performance of Organic-Inorganic Perovskites in Light-Emitting Diodes. , 2017, The journal of physical chemistry letters.

[8]  Changling Yu,et al.  Enhancement of the visible light activity and stability of Ag2CO3 by formation of AgI/Ag2CO3 heterojunction , 2014 .

[9]  Xiaogang Peng,et al.  Ideal CdSe/CdS Core/Shell Nanocrystals Enabled by Entropic Ligands and Their Core Size-, Shell Thickness-, and Ligand-Dependent Photoluminescence Properties. , 2017, Journal of the American Chemical Society.

[10]  Angshuman Nag,et al.  Beyond Colloidal Cesium Lead Halide Perovskite Nanocrystals: Analogous Metal Halides and Doping , 2017 .

[11]  Aram Amassian,et al.  Hybrid organic-inorganic inks flatten the energy landscape in colloidal quantum dot solids. , 2017, Nature materials.

[12]  Jasmina A. Sichert,et al.  Colloidal lead halide perovskite nanocrystals: synthesis, optical properties and applications , 2016 .

[13]  William W. Yu,et al.  Fine‐Tuned Multilayered Transparent Electrode for Highly Transparent Perovskite Light‐Emitting Devices , 2018, Advanced electronic materials.

[14]  H. Zeng,et al.  Stabilizing Cesium Lead Halide Perovskite Lattice through Mn(II) Substitution for Air-Stable Light-Emitting Diodes. , 2017, Journal of the American Chemical Society.

[15]  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.

[16]  Hongwei Song,et al.  Doping Lanthanide into Perovskite Nanocrystals: Highly Improved and Expanded Optical Properties. , 2017, Nano letters.

[17]  V. Klimov,et al.  Mn2+-Doped Lead Halide Perovskite Nanocrystals with Dual-Color Emission Controlled by Halide Content. , 2016, Journal of the American Chemical Society.

[18]  Ru‐Shi Liu,et al.  High-Performance CsPb1-x Snx Br3 Perovskite Quantum Dots for Light-Emitting Diodes. , 2017, Angewandte Chemie.

[19]  Noah D Bronstein,et al.  Essentially Trap-Free CsPbBr3 Colloidal Nanocrystals by Postsynthetic Thiocyanate Surface Treatment. , 2017, Journal of the American Chemical Society.

[20]  N. Wang,et al.  Interfacial Control Toward Efficient and Low‐Voltage Perovskite Light‐Emitting Diodes , 2015, Advanced materials.

[21]  Heng Zhang,et al.  Over 100 cd A−1 Efficient Quantum Dot Light‐Emitting Diodes with Inverted Tandem Structure , 2017 .

[22]  Youngsik Kim,et al.  Highly Stable Cesium Lead Halide Perovskite Nanocrystals through in Situ Lead Halide Inorganic Passivation , 2017 .

[23]  Chieh-Wei Chen,et al.  Top-emitting organic light-emitting devices using surface-modified Ag anode , 2003 .

[24]  D. Chung,et al.  Phase Stabilized α‐CsPbI3 Perovskite Nanocrystals for Photodiode Applications , 2018 .

[25]  H. Zeng,et al.  Surface Chemistry of All Inorganic Halide Perovskite Nanocrystals: Passivation Mechanism and Stability , 2018 .

[26]  Bright-Exciton Fine-Structure Splittings in Single Perovskite Nanocrystals. , 2016, Physical review letters.

[27]  William W. Yu,et al.  Bright Perovskite Nanocrystal Films for Efficient Light-Emitting Devices. , 2016, The journal of physical chemistry letters.

[28]  Yi Luo,et al.  Ce3+-Doping to Modulate Photoluminescence Kinetics for Efficient CsPbBr3 Nanocrystals Based Light-Emitting Diodes. , 2018, Journal of the American Chemical Society.

[29]  Wanjung Kim,et al.  Potassium Incorporation for Enhanced Performance and Stability of Fully Inorganic Cesium Lead Halide Perovskite Solar Cells. , 2017, Nano letters.

[30]  Sara Bals,et al.  Highly Emissive Divalent-Ion-Doped Colloidal CsPb1–xMxBr3 Perovskite Nanocrystals through Cation Exchange , 2017, Journal of the American Chemical Society.

[31]  Luyi Sun,et al.  Room-Temperature Synthesis of Mn-Doped Cesium Lead Halide Quantum Dots with High Mn Substitution Ratio. , 2017, The journal of physical chemistry letters.

[32]  Q. Akkerman,et al.  Fluorescent Alloy CsPbxMn1–xI3 Perovskite Nanocrystals with High Structural and Optical Stability , 2017, ACS energy letters.

[33]  E. Namdas,et al.  ITO‐free top emitting organic light emitting diodes with enhanced light out‐coupling , 2014 .

[34]  E. Waclawik,et al.  Visible‐Light‐Induced Selective Photocatalytic Oxidation of Benzylamine into Imine over Supported Ag/AgI Photocatalysts , 2014 .

[35]  H. Zeng,et al.  CsPbX3 Quantum Dots for Lighting and Displays: Room‐Temperature Synthesis, Photoluminescence Superiorities, Underlying Origins and White Light‐Emitting Diodes , 2016 .

[36]  Yizheng Jin,et al.  Solution-processed, high-performance light-emitting diodes based on quantum dots , 2014, Nature.

[37]  L. Quan,et al.  Highly Efficient Visible Colloidal Lead-Halide Perovskite Nanocrystal Light-Emitting Diodes. , 2018, Nano letters.

[38]  Chih-Jen Shih,et al.  Colloidal CsPbX3 (X = Cl, Br, I) Nanocrystals 2.0: Zwitterionic Capping Ligands for Improved Durability and Stability , 2018, ACS energy letters.

[39]  Lih Y. Lin,et al.  Highly stable cesium lead iodide perovskite quantum dot light-emitting diodes. , 2017, Nanotechnology.

[40]  Slow Auger Recombination of Charged Excitons in Nonblinking Perovskite Nanocrystals without Spectral Diffusion. , 2016, Nano letters.