Ultrathin nanoclay films with tunable thickness as barrier layers in organic light emitting devices

다국어 초록 (Multilingual Abstract)

Barrier films have been extensively used, such as in food packaging, flexible electronics and prescription medicines. Recently, clay films complexed with polymeric medium have received much attention as a promising candidate due to their outstanding physicochemical barrier properties. In this work, we employ the clay nanosheets film as an effective blocking layer for enhancing life-time and stability of OLED devices. Conventional OLED devices, in which PEDOT:PSS complexes are used as a hole transporting material, shows disadvantageous aspects in a view of the life-time of devices, primarily due to the diffusion of sulfonate moieties from dopant to emitting layer, eventually leading to a failure of devices or a gradual loss in the luminance efficiency. However, when the clay nanosheets film is inserted as a barrier layer between PEDOT:PSS and luminance material, interfacial diffusion and mixing can be significantly reduced without sacrificing the hole transport mechanism, which enables to obtain the enhanced device stability. Additionally, we reveal that the construction of clay nanosheets barrier is strongly dependent on the surface charge density of the substrate, whereby the electrostatic interaction and van der Waals attraction can be sophisticatedly balanced with each other.

목차 (Table of Contents)

• List of Figures 1
• Abstract 3
• 1.Introduction 5
• 2. Experimental 15
• A. Preparation of ultrathin nanoclay films 15
• B. Fabrication of Hybrid OLEDs 17
• C. Measurements 19
• 3. Results and Discussions 21
• 4. Conclusion 36
• 5. References 38