Preparation 8.5%-efficient submodule using 5%-efficient DSSCs via three-dimensional angle array and light-trapping layer

Abstract

Expanding the application area of photovoltaics to urban environments demands high efficiency under low-intensity lighting conditions, as well as omnidirectional light trapping. Dye-sensitized solar cells are of particular interest in this regard, owing to their superior electricity production in dim light; however, an improvement in dye-sensitized solar cells efficiency is required for successful implementation. We developed a light-trapping layer within the photoanode of dye-sensitized solar cells and configured these cells into an angled three-dimensional (3D) array creating a submodule to improve efficiency. The light-trapping layer increases the travel distance of the light within the photoanode, thus improving electron generation by the photons of the omnidirectional incident light. The 3D angled array suppresses recombination and internal resistance losses, improving the collection efficiency by increasing the relative cell surface area with respect to the light projection area. Using the proposed configuration, we achieved a dye-sensitized solar cells submodule efficiency of 8.5% using 5%-efficient dye-sensitized solar cells with a pot-shaped light-trapping layer and a 60° angled 3D array for the submodule. Considering that there is room for further improvement, our proposed photovoltaics configuration is expected to overcome the current limitations of dye-sensitized solar cells, thus providing promising photovoltaics modules for urban environments.