Impacts of both temperature and condensation on the band gap of photonic crystals around the freezing point

This work investigated the phenomena and cause of photonic band gap (PBG) shift under an open environment at -10 degrees C similar to 20 degrees C for the three-dimensional (3D) photonic crystals (PCs). The 3D PCs were composed of polystyrene spheres using the self-assembly method. The reflective gloss of 3D PC sample underwent non-monotonous color change within the temperature region. PBG of PCs first red-shifted during the cooling from room temperature. Later, the PBG blue-shifted when the temperature decreased from about 0 degrees C. The average transmittance through the PC sample within the visible range also increased first and then decreased with ambient temperature reduction. Influences from structure dimension, optical constants of involved materials, condensation and its phase change on PBG were all quantitatively investigated.

Automated summary

The study investigated the phenomena and causes of photonic band gap (PBG) shift in three-dimensional photonic crystals under different temperatures. It was found that PBG red-shifted initially during cooling from room temperature, then blue-shifted as the temperature decreased further. The transmittance of the photonic crystals also showed a non-monotonous change with ambient temperature reduction. Structural dimensions, optical constants, condensation, and phase change were all quantitatively analyzed for their influences on PBG.