| Popis: |
Photonic crystals are periodic structures that are formed from a material of certain refractive index organized into a regular lattice that is surrounded by a medium having a different refractive index. The difference between these refractive indices determines the nature of the so‐called photonic bandgap, which is analogous to the electronic bandgap in semiconductors. These materials are expected to find application in a range of new devices including “passives,” such as improved mirrors or filters, and “actives,” such as faster computers, higher‐band‐width communication systems, and even light‐harvesting structures that could improve the efficiency of solar cells. There are two approaches to forming photonic crystals: top‐down methods based on lithographically altering a starting material and bottom‐up methods, which use different techniques in order to assemble particles into ordered multilayers. Recent results obtained using the bottom up approach are described, with particular emphasis on the use of the Langmuir‐Blodgett method of producing photonic crystals in a highly controlled and reproducible manner. In addition, the use of advanced growth techniques such as atomic layer deposition and aerosol‐assisted chemical vapor deposition to infill the photonic crystals with different materials will be presented. |
