초록 |
We present a novel method to fabricate 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 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 the construction of clay nanosheets barrier is strongly dependent on the surface charge density of the substrate, whereby the electrostatic repulsion and van der Waals attraction can be sophisticatedly balanced with each other. |