Photocurrent Enhancement of Gold Nanoparticle Incorporated in ZnO as Electron Transport Layer in Hybrid Bulk Heterojunction Solar Cell Muhammad Cikal Merdeka (a*), Nur Fadhilah Syarif (a**), Priastuti Wulandari (a***)
a) Physics of Magnetism and Photonic Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10 Bandung 40132, West Java, Indonesia
Organic solar cells are currently one of the most popular researches related to renewable energy because the devices produced are lighter, more flexible, cheaper to produce, and relatively easy to manufacture in comparison to solar cells with inorganic semiconductor crystalline materials. Various solar cell structures have been developed either by using organic-inorganic hybrids, donor-acceptor blends in bulk heterojunction structures, or using inverted configurations in an effort to improve the performance efficiency of the device. However, there are still some problem in development of organic solar cells such as low efficiency and stability of the device that comes from the photocurrent generation mechanism in the structure of organic solar cells. In this study, we investigate the effect of localized surface plasmon resonance (LSPR) from gold nanoparticles incorporated into the electron transport layer (ETL) of Zinc Oxide in order to enchance the performance of bulk-heterojunction solar cell.
Synthesis of gold nanoparticles by capping 3-mercaptopropionic acid (AuMPA) was carried out by a modified reduction method following our previous method. TEM image shows the spherical shape of nanoparticles with a diameter size of ~51 nm. The absorbance spectra shows the surface plasmon peak of AuMPA in solution at ~527 nm. The fabrication of solar cells with the structure of ITO/ZnO:AuMPA/P3HT:PCBM/PEDOT:PSS/Ag was carried out using spin coating and thermal evaporation techniques. Incorporation of AuMPA into ZnAc solution was stable enough for AuMPA concentration in ZnAc less than 5 wt%. The fabricated solar cell reveals the enhancement in current density at short circuit condition (Jsc) from 13.5 mA/cm2 to 18.7 mA/cm2 with the addition of 0.88 wt% AuMPA in ZnAc solution along with the enhancement of power conversion efficiency (PCE) from 1.42% to 1.66% as characterized by J-V measurement. Upon further increasing the Au NPs content to 1.76 wt%, the device performance starts to decrease accompanied by decrease in both Jsc and Voc.
