Synthesis and photovoltaic properties of octacarboxy-metallophthalocyanine dyes applied in dye-sensitized solar cells

Abstract

A series of octacarboxy-metallophthalocyanine dyes, i.e., MgOCPc, MnOCPc, FeOCPc and ZnOCPc with different central metal ions were designed and synthesized by microwave irradiation. The effects of the introduction of different metal ions with variant 3d orbitals (3d0, 3d5, 3d6, and 3d10, respectively) in the centre of the phthalocyanine rings on the thermal, photophysical, and electrochemical properties of octacarboxy-metallophthalocyanines were characterized and evaluated in details. The results showed that ZnOCPc and MgOCPc with closed-shell metal ions and FeOCPc with an open-shell metal ion had excellent thermal property. However, MnOCPc with a half-full-shell metal ion had a lowest decomposition temperature and largest Q band red shifts. By theoretical calculation, the energy gaps of MgOCPc, MnOCPc, FeOCPc and ZnOCPc were 0.11, 0.10, 0.20 and 0.22V, respectively. Applied in TiO2 nanocrystalline dye-sensitized solar cells (DSSC), the photovoltaic properties of the four dyes were obtained under AM1.5 irradiation (100 mW cm-2).

Keywords

• octacarboxy-metallophthalocyanine dyes
• 3d orbital
• photophysical properties
• electrochemical properties
• energy gaps
• DSSC