We show that arrays of emissive nanorod structures can exhibit strong photonic crystal behavior, via observations of the far-field luminescence from core-shell and quantum disc InGaN/GaN nanorods. The conditions needed for the formation of directional Bloch modes characteristic of strong photonic behavior are found to depend critically upon the vertical shape of the nanorod sidewalls. Index guiding by a region of lower volume-averaged refractive index near the base of the nanorods creates a quasi-suspended photonic crystal slab at the top of the nanorods which supports Bloch modes. Only diffractive behavior could be observed without this region. Slab waveguide modelling of the vertical structure shows that the behavioral regime of the emissive nanorod arrays depends strongly upon the optical coupling between the nanorod region and the planar layers below. The controlled crossover between the two regimes of photonic crystal operation enables the design of photonic nanorod structures formed on planar substrates that exploit either behavior depending on device requirements.
|Number of pages||7|
|Journal||Journal of Applied Physics|
|Early online date||24 Jul 2014|
|Publication status||Published - 31 Jul 2014|
FingerprintDive into the research topics of 'Strong photonic crystal behavior in regular arrays of core-shell and quantum disc InGaN/GaN nanorod light-emitting diodes'. Together they form a unique fingerprint.
- Department of Electronic & Electrical Engineering - Senior Lecturer
- Centre for Nanoscience and Nanotechnology
- Centre for Sustainable and Circular Technologies (CSCT)
- Condensed Matter Physics CDT
- Electronics Materials, Circuits & Systems Research Unit (EMaCS)
- Centre for Integrated Materials, Processes & Structures (IMPS)
Person: Research & Teaching, Core staff