Thermally tuning of the photonic band gap of SiO2 colloid-crystal infilled with ferroelectric BaTiO3

Abstract

SiO 2 colloid crystal infilled with BaTiO3 was synthesized by a process of self-assembly in combination of a sol–gel technique. It is found that infilling of the fully crystallized BaTiO3 into the colloid assembly can enhance the photonic band gap significantly. In the vicinity of the ferroelectric phase transition point of BaTiO3 (100–150 °C), the photonic band gap of the assembly exhibits a strong temperature dependence. At the Curie point, the band gap has a 20 nm redshift, and the optical transmittance reaches its minimum. Such a temperature-tuning effect in the photonic band gap should be of high interest in device applications.