Study on optical absorption and conductivity of hybrid ZnO nanorod/graphene

Abstract

The main keys in developing solar cells are their optical absorption and electron transfer (optical conductivity) levels. To enhance these two characteristics, an electron transport layer (ETL) was added to the solar cell, which is used to prevent electron recombination. Zinc oxide nanorod (ZnO NR) is one of the potential ETL candidates in the new generation of solar cells due to its high electron transfer. To optimize the use of ZnO NR in new generation solar cells, we combine NR ZnO with graphene, into a hybrid ZnO NR/graphene system. Optical absorption and conductivity of hybrid ZnO NR/graphene were studied using spectroscopic ellipsometry. A significant change in ellipsometry spectra has been observed, which increases with a higher number of graphene in the hybrid systems. Furthermore, the role of graphene on the optical absorption and conductivity of hybrid systems was investigated through fittings by applying the effective medium approximation (EMA) model. This study will provide a good understanding of optical absorption and optical conductivity of hybrid ZnO NR/graphene, which is an important key in the development of high-performance new generation solar cells.