Abstract

Within the growing solar cell market, the field of organic solar cells is one of the cutting-edge topics, because organic materials offer the possibility of low-cost, easy, and large-scale production. Besides other crucial aspects of organic solar cell performance enhancement, such as materials, material composition, and device design [1], light harvesting and therefore light management inside these cells is of utmost importance. Light management inside solar cells – not only organic ones – can be realized by so-called light-trapping structures (LTSs) which can be implemented inside the active layers of solar cells to provide the possibility to reflect the light multiple times, thereby elongating the optical path, or they can be applied externally on top of the cells to form as well an antireflective coating and a light collection unit. The fabrication of tailored LTSs for both cases can be realized by structuring of materials that are accessible to nonlinear refractive index changes [2]. Nonlinear azopolymer layers, e.g., can change their refractive index by light induced cis-trans isomerization processes [3].

© 2015 IEEE