Executive Summary : | Photonic crystals (PhCs) are materials with varied refractive indices that can forbid light propagation and exhibit the photonic band gap (PBG). These materials are used in solar cells and light-emitting diodes. However, the fabrication of these materials in three-dimensional (3D) is not yet optimized. Typically, they are made using top-down lithographic or bottom-up assembly methods, which are cheaper and more convenient to scale up. Self-assembled colloidal crystals (CCs) are suitable candidates for PhCs due to their size and ability to interact with visible light. The construction of the desired structure is crucial, and the challenge lies in controlling interactions among building blocks at nanoscales. Deoxyribonucleic acid (DNA) is a suitable colloid functionalizing candidate for self-assembly due to its specificity of Watson-Crick base pairing. DNA-coated colloids (DNACCs) have been attempted to construct nanostructures using spherical colloids, but the low symmetry of an assembled CC and the efficient colloidal interactions due to flat anisotropic surfaces make them ideal for PhCs.
The project aims to develop design rules using different design parameters of DNA-coated anisotropically shaped colloids to achieve a targeted 3D structure with the targeted PBG. Due to the wide variety of design parameters, numerical simulations will be employed for experiments. A coarse-grained model will be developed, using the Monte Carlo technique for hybridization and molecular dynamics method for colloidal motion. Customized band structure determination software will be used to determine the PBG. |