| 초록 |
Since on-current is proportional to carrier mobility and carrier density in the channel, one way to increase on-current at low voltage is to use high-k gate insulators, which enhance field induced carrier density. However, most high-k dielectric materials used for OTFT are inorganic materials and hence are usally brittle and expensive to prepare. In order to apply high-k gate insulator to flexible display, it is necessary to develop cheap and easy way to make gate insulator with high dielectric constant and mechanical flexibility. Therefore nanocomposite dielectric layers consisting of poly-4-vinyl phenol(PVP) and Ba0.65Sr0.35TiO3(BST) nanoparticles, high-k materials, were prepared for OTFT gate insulators. Although the primary particle size of BST are smaller than 50nm, these particles show broad size distribution because of aggregation and agglomerization of the primary particles. They were dispersed in the organic solvent and incoporated into polymer matrix homogeneously and then nanocomposites thin film were prepared using spin coating method. Since the surface roughness influences electrical performance of the device, BST nanoparticles which were dispersed in organic solvent were centrifuged to sort the size of particles and then nanocomposite thin film had low surface roughness and improved electrical properties compared with the film incorporated the bare BST nanoparticles. |
