유연한 유기태양전지의 수분 투습 방지를 위해 원자층 증착법으로 제조된 Al 2 O 3 박막에 대한 연구

A moisture barrier layer with high density and uniformity is essential for increasing the lifespan of optoelectronic devices such as flexible organic solar cells, LEDs, and photodetectors. In this study, various surface pre-treatments (O2 plasma, UVO treatment, Al seed layer, and thermal annealing process) were performed on a polyethylene naphthalate (PEN) film to form a functional group of chemical adsorption with the atomic layer deposition (ALD) precursor. We investigated the effect of the surface pre-treatment of a PEN substrate for a deposition of Al2O3 thin film in terms of the deposition uniformity and water vapor transmittance rate (WVTR). For example, the root mean square roughness of the bare PEN film/Al2O3 was RRMS=3.26 nm, whereas the O2 plasma treated PEN film/Al2O3 had RRMS=0.99 nm because of the presence of a functional group. As a result, WVTR of bare PEN film/Al2O3 was 0.83 g/m²/day, whereas that of O2 plasma treated PEN film/Al2O3 decreased to 0.38 g/m²/day.