Theoretical Demonstration of Efficiency Enhancement of Dye-Sensitized Solar Cells with Double-Inverse Opal as Mirrors

Herein we describe the employment of double-inverse opal (DIO) as a novel optical element and present a theoretical analysis of the efficiency enhancement of the designed DSSCs. We find that, compared to inverse opal (IO) as the optical element, the presence of small spheres in 10 (i.e., DIO structure) produces a great light-scattering effect and broader reflection region, leading to considerable enhancement of the photocurrent efficiency of cells. Dye-sensitized solar cells (DSSCs) with one DIO layer as a mirror has a photocurrent efficiency enhancement up to 47%, which is a large improvement compared to that of the IO-coupled one (28%). More remarkably, double DIO layers as a scattering layer lead to efficient enhancement of the absorptances of DSSCs in the whole visible spectrum range (400-800 nm) and a distinct increment of about 80% of photocurrent efficiency with respect to standard ones. In this work, the optimum structural parameters of such DIO optical elements needed to achieve an efficient photocurrent efficiency enhancement are provided.