High-Efficiency Cu–In–S Quantum-Dot-Light-Emitting Device Exceeding 7%

We report on the unique synthesis of heterostructured core/shell Cu–In–S (CIS)/ZnS quantum dots (QDs) from a shelling perspective and fabrication of high-efficiency QD light-emitting diodes (QLEDs) with a standard device architecture. Onto CIS core QDs ZnS shelling of extraordinarily long duration is attempted along with the multiple injections of shell precursors. Three CIS/ZnS QDs obtained through different shelling periods of time are prepared and then individually employed as an emitting layer (EML) of solution-processed, multilayered QLED comprising a hole transport layer of poly((9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-s-butylphenyl))diphenyl-amine) (TFB) and an electron transport layer of ZnO nanoparticles. We observe a remarkable dependence of device performance on the type of QDs and attribute this presumably to different QD heterostructural details as a function of shelling duration. Our best device integrated with the longest-shelled QDs displays excellent current efficiency of 18.2 cd/A ...

[1]  NoSoung Myoung,et al.  Highly Efficient, Color-Reproducible Full-Color Electroluminescent Devices Based on Red/Green/Blue Quantum Dot-Mixed Multilayer. , 2015, ACS nano.

[2]  P. Holloway,et al.  Stable and efficient quantum-dot light-emitting diodes based on solution-processed multilayer structures , 2011 .

[3]  Haizheng Zhong,et al.  Hydroxyl-Terminated CuInS2 Based Quantum Dots: Toward Efficient and Bright Light Emitting Diodes , 2016 .

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

[5]  Jingkang Wang,et al.  Near‐Band‐Edge Electroluminescence from Heavy‐Metal‐Free Colloidal Quantum Dots , 2011, Advanced materials.

[6]  Jaehyun Park,et al.  CuInS2/ZnS core/shell quantum dots by cation exchange and their blue-shifted photoluminescence , 2011 .

[7]  Zhan'ao Tan,et al.  Highly Emissive and Color‐Tunable CuInS2‐Based Colloidal Semiconductor Nanocrystals: Off‐Stoichiometry Effects and Improved Electroluminescence Performance , 2012 .

[8]  Sergio Brovelli,et al.  Breakdown of volume scaling in Auger recombination in CdSe/CdS heteronanocrystals: the role of the core-shell interface. , 2011, Nano letters.

[9]  X. Zhong,et al.  Color-Tunable Highly Bright Photoluminescence of Cadmium-Free Cu-Doped Zn-In-S Nanocrystals and Electroluminescence , 2014 .

[10]  Ki-Heon Lee,et al.  Highly efficient, color-pure, color-stable blue quantum dot light-emitting devices. , 2013, ACS nano.

[11]  D. Y. Yoon,et al.  Bright and efficient full-color colloidal quantum dot light-emitting diodes using an inverted device structure. , 2012, Nano letters.

[12]  Ki-Seok An,et al.  Performance Improvement of Quantum Dot-Light-Emitting Diodes Enabled by an Alloyed ZnMgO Nanoparticle Electron Transport Layer , 2015 .

[13]  Jian Xu,et al.  Employing heavy metal-free colloidal quantum dots in solution-processed white light-emitting diodes. , 2011, Nano letters.

[14]  J. Hwang,et al.  Cu−In−Ga−S quantum dot composition-dependent device performance of electrically driven light-emitting diodes , 2014 .

[15]  V. Bulović,et al.  High-efficiency quantum-dot light-emitting devices with enhanced charge injection , 2013, Nature Photonics.

[16]  Kookheon Char,et al.  InP@ZnSeS, Core@Composition Gradient Shell Quantum Dots with Enhanced Stability , 2011 .

[17]  K. Char,et al.  Gram-Scale One-Pot Synthesis of Highly Luminescent Blue Emitting Cd1-xZnxS/ZnS Nanocrystals , 2008 .

[18]  Heesun Yang,et al.  All-solution-processed, multilayered CuInS₂/ZnS colloidal quantum-dot-based electroluminescent device. , 2014, Optics letters.

[19]  Alexander L Efros,et al.  Suppression of auger processes in confined structures. , 2010, Nano letters.

[20]  P. Holloway,et al.  High-efficiency light-emitting devices based on quantum dots with tailored nanostructures , 2013, Nature Photonics.

[21]  Yixing Yang,et al.  Efficient and bright colloidal quantum dot light-emitting diodes via controlling the shell thickness of quantum dots. , 2013, ACS applied materials & interfaces.

[22]  H. Chae,et al.  Improved electroluminescence of quantum dot light-emitting diodes enabled by a partial ligand exchange with benzenethiol , 2016, Nanotechnology.

[23]  Myeongjin Park,et al.  Influence of Shell Thickness on the Performance of Light‐Emitting Devices Based on CdSe/Zn1‐XCdXS Core/Shell Heterostructured Quantum Dots , 2014, Advanced materials.

[24]  H. Chae,et al.  Polymer and small molecule mixture for organic hole transport layers in quantum dot light-emitting diodes. , 2013, ACS applied materials & interfaces.

[25]  K. Char,et al.  Highly efficient cadmium-free quantum dot light-emitting diodes enabled by the direct formation of excitons within InP@ZnSeS quantum dots. , 2013, ACS nano.

[26]  Nathan T. Shewmon,et al.  High-efficiency, low turn-on voltage blue-violet quantum-dot-based light-emitting diodes. , 2015, Nano letters.

[27]  Heesun Yang,et al.  Synthesis of color-tunable Cu–In–Ga–S solid solution quantum dots with high quantum yields for application to white light-emitting diodes , 2012 .

[28]  Lazaro A. Padilha,et al.  Controlling the influence of Auger recombination on the performance of quantum-dot light-emitting diodes , 2013, Nature Communications.

[29]  Kookheon Char,et al.  Single-Step Synthesis of Quantum Dots with Chemical Composition Gradients , 2008 .

[30]  Zhenghong Lu,et al.  Colloidal CuInSe2 Nanocrystals in the Quantum Confinement Regime: Synthesis, Optical Properties, and Electroluminescence , 2011 .

[31]  Yongwoo Kwon,et al.  Over 40 cd/A efficient green quantum dot electroluminescent device comprising uniquely large-sized quantum dots. , 2014, ACS nano.