Preparation of photonic crystal heterostructures composed of two TiO2 inverse opal films with different filling factors

A novel fabrication procedure for preparing TiO2 inverse opal heterostructures is presented in this paper. In this procedure, TiO2 inverse opal film was fabricated by filling a polystyrene (PS) opal photonic crystals template through a liquid-phase deposition (LPD) technique. The PS opal photonic crystals templates were fabricated using a room temperature floating self-assembly (RTFSA) method, which was recently developed in our lab. And a photonic crystal heterostructure composed of two TiO2 inverse opal films with different filling factors was fabricated through the sequential deposition, infiltration and removal of two PS opal template films. Herein, the two opal template films are assembled with PS microspheres of the same size. The inverse opal heterostructures with different photonic band structures can be easily fabricated by varying the deposition time of the LPD step.