Synthesis and spectral properties of double D–π–A mono-cyanines as well as preparation of near infrared silicon-based materials

Abstract

Three kinds of new double D–π–A mono-cyanines D1, D2 and D3 were synthesized for the surface modification of monocrystalline silicon to prepare near infrared silicon-based materials. There was a strong surface photovoltage response in the range of 900–1250 nm compared with silicon materials when double D–π–A mono-cyanines were bound on the monocrystalline silicon material surface. To explore the effect of the double D–π–A mono-cyanines on the light absorption characteristics of silicon materials, the absorption properties, films on monocrystalline silicon surfaces and the surface photovoltage response of three double D–π–A mono-cyanines were investigated. The results demonstrated that the order of the intensity of the surface photovoltage response was Si/D3 > Si/D2 > Si/D1, and no absorption properties of the silicon materials in the near infrared region were improved, yielding near infrared silicon-based materials.