PEDOT:PSS 정공 수송층에 금 나노입자를 첨가한 유기태양전지의 제작 및 특성 연구

Fabrication and Characterization of Organic Solar Cells with Gold Nanoparticles in PEDOT:PSS Hole Transport Layer

본 논문은 캐리어의 이동도 및 전도도를 개선하고, 흡수된 빛의 이동 경로를 증가시켜 광흡수도를 높이기 위하여 정공 수송층 재료에 금 나노입자를 첨가하여 유기태양전지를 제작하였다. 광활성층으로는 P3HT와 PCBM의 bulkheterojunction 구조를 사용하였다. 유기태양전지에서 금 나노입자를 첨가한 정공 수송층의 효과를 관찰하기 위하여 금 나노입자의 첨가량(0, 0.5, 1.0 wt% Au)과 열처리온도(상온, 110℃, 130℃, 150℃)에 따른 광학적·전기적 특성을 조사하였다. 최대전력변환효율을 갖는 유기태양전지는 0.5 wt% 금 나노입자 첨가한 소자와 130℃에서 열처리한 소자에서 관찰되었다. 이때 유기태양전지의 전기적 특성은 금 나노입자를 0.5 wt% 첨가한 경우, 단락전류밀도, 곡선인자 및 전력변환효율은 각각 10.2 mA/cm², 55.8% 및 3.1%로 나타났으며, 130℃에서 열처리한 경우, 12.0 mA/cm²의 단락전류밀도와 64.2%의 곡선인자를 가지며, 4.0%의 전력변환효율이 관찰되었다.

In this paper, organic solar cells(OSCs) based on bulk-heterojunction structures were fabricated by spin coating method using polymer P3HT and fullerene PCBM as a photoactive layer. The fabricated OSCs had a simple glass/ITO/PEDOT:PSS/P3HT:PCBM/Al structures. The photoactive layer of mixed P3HT:PCBM was formed with 1:1 weight ratio. The hole transport layer(HTL) was used conducting polymer PEDOT:PSS concentration with gold nanoparticles. The annealing temperature and concentration of nanoparticles in HTL were verified to improve the OSC characterization. The percentage of gold nanoparticles in HTL were 0.5 wt% and 1.0 wt%, and the surface morphology, electrical properties and absorption intensities were investigated. The devices were 0.5 wt%, and the highest 3.1% of the powder conversion efficiency(PCE), 10.2 mA/cm² of the maximum short circuit current density(JSC), 0.535V of the open circuit voltage(VOC) and 55.8% of the fill factor(F.F) could be obtained when the nanoparticle concertration was 0.5 wt%. The annealing temperature of HTL was 110℃, 130℃, 150℃ in vacuum oven and measured the absorption intensities, surface morphology, crystallinity and electrical properties were investigated. The best property was obtained in HTL annealed at 130℃ for gold nanoparticles of 0.5 wt%, showing that JSC, VOC, F.F and PCE were about 12.0 mA/cm², 0.525V, 64.2% and 4.0%, respectively.