다양한 2차원 나노물질 합성 및 응용

Abstract

In this work, we studied the synthesis of two-dimensional (2D) nanomaterials using chemical vapor deposition (CVD). Firstly, Tailored CVD graphene as a transparent and flexible gas barrier was synthesized by controling defect densities. Secondly, To resolve the bandgap problem of the graphene, we synthesized 2D hexagonal boron-carbon-nitride (h-BCN) materials and fabricated organic light emitting diodes (OLED) with h-BCN as a light emitter. Graphene with chemical inertness and complete impermeability to any gases can be used as a gas barrier against water and oxygen diffusion and protective layer to prevent the metal electrodes from oxidation, corrosion, and degradation in electrochemical systems. We use a combined approach of electro-chemical polishing (ECP) and two-step growth methods to improve the gas barrier property of graphene without an increase in the layer numbers or additional fabrication process. 2step-ECP graphene on PET exhibits the lowest water vapor transmission rate (WVTR) value of 0.665±0.046 g/m2-day, which is 60% less than bare PET due to large domains and improved graphene quality with minimized defects. The CVD graphene reported here could open up the possibility for exploring graphene-based gas barrier. Ternary h-BCN emerge as a new active materials owing to its interesting and attractive semiconductor properties with tunable energy bandgap which can be controlled by their chemical stoichiometry, atomic arrangement and geometry structure. We use a n-tri-methyl borazine (C3H12B3N3) as a precursor to grow high-quality h-BCN layers by CVD using Ni foils. Large area h-BCN layers were synthesized on Ni foils where the optical bandgap of h-BCN layers were found to be about 2 eV. Recently, the detailed opto-electrical studies of h-BCN synthesized by various approaches and the adoption of the field effect transistors (FET) using them have been introduced, but application of optical device has not yet reported until now. Therefore, we fabricate OLED using h-BCN as a light emitter for the first time. The current-voltage characteristics and electroluminescence (EL) performance exhibit that OLED fabricated by h-BCN layers well-operate and uniformly emit over the whole emission area.