TiO2-CNT composites를 광전극에 적용한 염료감응형 태양전지 제조

Abstract

염료감응형 태양전지(DSSCs,Dye-Sensitized Solar Cells)는 가시광선을 흡수하여 전자-홀 쌍을 생성할 수 있는 염료분자와 생성된 전자를 전달하는 전이금속 산화물을 구성 재료로 하는 광 전기화학적 태양전지이다. 염료감응형 태양전지에서 중요한 구성요소 중 하나인 광 전극은 투명하면서도 전극 역할을 할 수 있을 만큼 전기 전도도가 높은 소재가 사용되며, 가장 널리 사용되는 광 전극 물질은 TiO2이다. 탄소나노튜브(CNT)는 탄소가 육각형의 구조를 유지하면서 튜브 형태로 이루어져 화학적 안정성이 우수하다. 전기적으로는 전자 전도도가 우수하고 높은 전류밀도를 가지며 열적으로도 매우 안정 할 뿐만 아니라 넓은 표면적 때문에 적정량을 포함할 때 광수확 입자를 고정시키는 골격의 역할을 할 수 있다. 따라서 본 연구에서는 상기 두 가지 물질을 복합하여 나노구조체를 제조하여 염료감응형 태양전지의 광 전극으로의 활용성을 알아보았다. 계면활성제인 Triton X-100을 이용하여 TiO2가 CNT 표면에 코팅된 TiO2-CNT 나노구조체를 제조하였다. 제조된 TiO2-CNT 나노구조체를 염료감응형 태양전지의 광 전극 물질로 적용시키면 TiO2만의 염료감응형 태양전지보다 Short circuit current density (Jsc) 와 fill factor (FF)가 향상되어 결과적으로 염료감응 태양전지의 변환 효율이 증가함을 확인하였다. |Multiwalled carbon nanotube (MWCNT)-TiO2 powder prepared by a modified sol-gel polymerization and fabricated DSSCs based on TiO2-CNT composites as a photoanode using a surfactant,Triton X-100. The morphology and the structure of the composites were investigated with a scanning electron microscopy (SEM) and a transmission electron microscopy (TEM). As a result, it was verified that TiO2-CNT composites were successfully prepared and MWCNT was coated with TiO2. Fourier transform infra-red (FT-IR) and Wide angle X-ray diffraction (WAXD) were also used to investigate the micro structural properties. The photovoltaic performances of the TiO2-CNT composites with various ratios for a photoanode of DSSCs were compared with the conversional DSSC. Short circuit current density (Jsc), fill factor (FF) and conversion efficiency (η) of the TiO2-CNT composites were improved compared to conversional DSSC. The highest efficiency of the DSSCs in this study was 4.43%. Consequently, it can be explained by the fact that these types of nanostructures are efficient materials as a photoanode for DSSCs.; Multiwalled carbon nanotube (MWCNT)-TiO2 powder prepared by a modified sol-gel polymerization and fabricated DSSCs based on TiO2-CNT composites as a photoanode using a surfactant,Triton X-100. The morphology and the structure of the composites were investigated with a scanning electron microscopy (SEM) and a transmission electron microscopy (TEM). As a result, it was verified that TiO2-CNT composites were successfully prepared and MWCNT was coated with TiO2. Fourier transform infra-red (FT-IR) and Wide angle X-ray diffraction (WAXD) were also used to investigate the micro structural properties. The photovoltaic performances of the TiO2-CNT composites with various ratios for a photoanode of DSSCs were compared with the conversional DSSC. Short circuit current density (Jsc), fill factor (FF) and conversion efficiency (η) of the TiO2-CNT composites were improved compared to conversional DSSC. The highest efficiency of the DSSCs in this study was 4.43%. Consequently, it can be explained by the fact that these types of nanostructures are efficient materials as a photoanode for DSSCs.