Semiconductor nanomaterials based photodetectors and organic light-emitting diodes for flexible integrated photonic systems

다국어 초록 (Multilingual Abstract)

In recent years, development of several types of flexible photonic devices has received much attention due to their promising applicability as one of basic components for flexible integrated photonic systems. It that regard, it is important to high-performance photonic devices such as photodetectors and organic light-emitting diodes (OLEDs) on flexible substrates. On basis of advance researches, flexible integrated photonic systems are demonstrated on the flexible substrates by combining those photonic devices through simple fabrication procedures. In this thesis, the photodetectors based on semiconductor nanomaterials and the OLEDs with amorphous ZnO-doped In2O3 anodes were fabricated on the flexible substrates and their characteristics were investigated in detail. And then, the flexible integrated photonic systems were developed by means of interconnection of the photonic devices with other photonic and electronic devices. In chapter 1, characteristics of the flexible photodetectors based on semiconductor nanomaterials and the flexible OLEDs were introduced with explanation of their demands for the flexible integrated photonic systems. Chapter 2 described experimental procedures for the fabrication of the photodetectors, the OLEDs, and the integrated photonic systems on the flexible substrates. In Chapter 3, modulation properties of the flexible integrated photonic systems, including investigation of characteristics of individual photonic and electrical devices, were discussed. The promising potential of flexible integrated photonic systems for next generation photonics was described in conclusion.

목차 (Table of Contents)

• Chapter 1. Introduction 1
• 1.1 Background and Motivation 2
• 1.2 Semiconductor Nanomaterials Based Flexible Photodetectors 8
• 1.2.1 Fundamental of Photodetectors 8
• 1.2.2 Semiconductor Nanomaterials Based Photodetectors for Flexible Substrates 13
• 1.2.3 Integration of Photodiode with Nanowires Based Field-Effect Transistor on Flexible Substrate 21
• 1.3 Flexible Organic Light-Emitting Diodes 23
• 1.3.1 Fundamental of Organic Light-Emitting Diodes 23
• 1.3.2 Organic Light-Emitting Diodes with Flexible Transparent Electrode for Flexible Substrates 26
• 1.3.3 Hybrid Light-Emitting Diodes with Nanoparticles for Flexible Substrates 29
• 1.3.4 Thermal Degradation of Organic Light-Emitting Diodes 36
• 1.3.5 Integration Organic Light-Emitting Diode with Nanowires Based Photodetector on Flexible Substrate 40
• Chapter 2. Experimental Procedures 43
• 2.1 Fabrication of Photodetectors Based on Nanoparticles Films and/or Nanowires for Flexible Substrates 44
• 2.1.1 Flexible Photodetector Composed of HgS Nanoparticles Film 44
• 2.1.2 Prototype Photodiode Composed of Cu2O Nanoparticles Film and Single ZnO Nanowire 45
• 2.1.3 Flexible Photodiode Composed of CdTe Nanoparticles Film and Single ZnO Nanowire 46
• 2.2 Fabrication of Organic Light-Emitting Diodes for Flexible Substrates 48
• 2.2.1 Flexible Transparent Electrode 48
• 2.2.2 Flexible Organic Light-Emitting Diode with a-IZO anode 48
• 2.2.3 Hybrid Light-Emitting Diode Composed of ZnO Nanoparticles Film as Buffer Layer 50
• 2.2.4 Hybrid Light-Emitting Diode Composed of CdSe/Cd/ZnS Core-Shell Nanoparticles Embedded in Conducting Polymer as Emissive Layer 52
• 2.2.5 Organic Light-Emitting Diodes with Various Electron Transport Layers 54
• 2.3 Fabrication of Integrated Photonic Systems on Flexible Substrates 58
• 2.3.1 ZnO film/Si NWs Photodiode Integrated with Si NWs Based Field-Effect Transistor on Flexible Substrate 58
• 2.3.2 Organic Light-Emitting Diode Integrated with Si Nanowires Based Photodetector on Flexible Substrate 62
• Chapter 3. Results and Discussion 65
• 3.1 Photocurrent Characteristics of Photodetectors Composed of Nanoparticles Films and/or Nanowires for Flexible Substrates 66
• 3.1.1 Flexible Photodetector Composed of HgS Nanoparticles Film 66
• 3.1.2 Prototype Photodiode Composed of Cu2O Nanoparticles Film and Single ZnO Nanowire 73
• 3.1.3 Flexible Photodiode Composed of CdTe Nanoparticles Film and Single ZnO Nanowire 81
• 3.2 Electroluminescence Characteristics of Organic Light-Emitting Diodes for Flexible Substrates 91
• 3.2.1 Flexible Transparent Electrode 91
• 3.2.2 Flexible Organic Light-Emitting Diode with a-IZO anode 99
• 3.2.3 Hybrid Light-Emitting Diode Composed of ZnO Nanoparticles Film as Buffer Layer 108
• 3.2.4 Hybrid Light-Emitting Diode Composed of CdSe/Cd/ZnS Core-Shell Nanoparticles Embedded in Conducting Polymer as Emissive Layer 114
• 3.2.5 Organic Light-Emitting Diodes with Various Electron Transport Layers 123
• 3.3 Modulation Characteristics of Integrated Photonic Systems on Flexible Substrates 134
• 2.3.1 ZnO film/Si NWs Photodiode Integrated with Si NWs Based Field-Effect Transistor on Flexible Substrate 134
• 2.3.2 Organic Light-Emitting Diode Integrated with Si Nanowires Based Photodetector on Flexible Substrate 146
• Chapter 4. Conclusions 156
• References 161