Chemical approaches to three-dimensional semiconductor photonic crystals

We review recent efforts to make three-dimensional semiconductor photonic crystals using self-assembly techniques. These approaches, which utilize a synthetic opal as a template to shape the semiconductor material (see Figure), provide a simple and inexpensive alternative to lithographic methods. Since the resulting structures can, in principle, have a complete photonic bandgap - a property that would allow ultimate control over the flow of light - these materials may have serious implications for modern photonics.