Invited review article in the special issue of Advanced Materials 12, (16), 1176 (2000)

Publisher: Wiley, 2000.

Synthetic opals can provide a simple and inexpensive template for obtaining optical photonic crystals, materials that are periodic on an optical length scale. Such structures are desirable since they have the potential to exhibit a complete photonic band gap. However, to achieve this, the photonic crystal must be made from a material with a high refractive index (>2.8). This requirement has been difficult to satisfy and has limited research on photonic band gap materials. Here, we review recent successes in combining synthetic opals with semiconductor infiltration methods to obtain high-refractive-index inverted opals. These structures should allow, for the first time, the existence of the photonic band gap to be fully explored in chemically-assembled materials. (51 References)