Dye-Sensitized Solar Cells with Designable Encryption

Abstract

Current thin-film solar cells only serve as power generators. Enabling the thin-film solar cells to carrying optical information usually involves sacrificing the area of the light-absorbing layers. This makes the power generation and carrying the information irreconcilable. In this paper, the photoanode surface of the dye-sensitized solar cells (DSSCs) is structured by using laser direct writing assisted nanoimprint technology. The structured photoanodes (SPH) appear visually resemble conventional photoanodes, but contain encrypted information at the microscopic level. The encrypted information is designed according to the principles of diffraction optics, which will be revealed only under laser illumination. The structured surface increases the surface roughness of photoanodes, which enhances dye adsorption by 15.0%, resulting in a 14.8% improvement in power conversion efficiency of DSSCs. The incident photon-to-current conversion efficiency and UV-vis spectrophotometer tests further confirm that the increase in power conversion efficiency is attributable to the enhancement of dye adsorption.

Keywords: DSSCs, Encrypted information, Efficiency improvement, Micro/nano Fabrication