New Phenoxazine-Based Organic Dyes with Various Acceptors for Dye-Sensitized Solar Cells: Synthesis, Characterization, DSSCs Fabrications and DFT Study

Abstract

As sensitizers, a series of organic dyes containing phenoxazine is synthesized for use in dye-sensitized solar cells (DSSCs). The dyes were characterized using FT-IR, NMR and UV experiments. Quantum chemical calculations were used to gain insight into the structural, electronic and photophysical properties including its as-synthesized sensitizers, as well as to allocate experimental spectroscopic results. It has been observed that increasing the electron-donor potential and the [Formula: see text]-conjugated bridge of the dyes would increase the photovoltaic performance. The obtained two dyes have substantially higher efficiency of 6.6 and 6.4%, respectively, under the modeled AM1.5G conditions. Efficient electron injection from the excited sensitizer to the conduction band of TiO2 film occurs due to further delocalizing electrons in the [Formula: see text]-conjugated bridge and donor areas of the dyes. Using cyclic voltammetry, the electrochemical efficiency of BPA and BPCA was evaluated, and reversible oxidation signals were reported.