Synthesis of novel light harvesters based on perylene imides linked to triphenylamines for Dyes Sensitized Solar Cells

Abstract

Dye Sensitized Solar Cells (DSSCs) are promising optoelectronic devices that use renewable energy and organic or organometallic dyes as light harversters. They exhibit moderate overall efficiencies of power conversion that can be increased by improving the light-harvesting capacity of the organic dyes. Here, we report the synthesis, structural and electronic properties of two novel dyes based on perylene imides PI-1 and PI-2 as well as their application in DSSCs. In our design, design triphenylamine electron donors were linked to perylene-3,4,9,10-tetracarboxylic dianhydride derivative. The new dyes showed a broad absorption spectrum in the visible region as well as a strong push – pull electronic interaction determined computationally. Photovoltaic values for these dyes were not higher than previously reported compounds based on perylenes, with the best photovoltaic performance observed for the DSSCs based on PI-2, with an overall conversion efficiency of 1.3% under AM 1.5 irradiation (100 mW cm−2). Although the electron transport to the TiO2 surface for PI-1 and PI-2 was not efficient enough to result in a high photovoltaic behavior, our design has afforded dyes exhibiting a more efficient light capture in the visible region.