Research objectives and content
We propose a systematic investigation of the luminescence behaviour of photonic microstructures in optical wavelengths over a wide range of material systems. The work will consist in the realisation and characterisation of microstructures in three lattice geometries, triangular, "graphite" and "boron nitride", in III-V and Il-VI materials, both with air holes in semiconductor and pillars of semiconductor in air. The samples will be patterned by electron beam lithography and dry-etching. Surface treatments after dry-etching, such as sulphide passivation or anodic oxidation will be investigated in order to improve the quality of the microstructures. Another challenge will be to increase the depth of etching in the microstructures and hardened silicon nitride could be used as a more robust mask instead of silica. Finally we shall introduce defects in the photonic structure. The samples will be characterised by several different methods including high resolution scanning electron microscopy, photoreflectance, photoluminescence and waveguide transmission experiments. We expect to see major effects on spontaneous emission produced by photonic microstructures. The impact of a defect on the transmission will be the possibility to obtain one emission mode allowed in the bandgap. This phenomenon is of great importance for laser and very narrow band filter applications of photonic microstructures . Training content (objective, benefit and expected impact)
- use of electron beam lithography and reactive ion etching and special requirements for the design of photonic microstructures: regularity of small (about 100nm in diameter), closely packed features. - investigation of different materials with different behaviour - high technology advantageous to the applicant's future career in research, in academic or industrial environment.
Links with industry / industrial relevance (22)
- Interest of British Telecom, which is partially funding work at Glasgow University on InP-based photonic microstructures. - Interest of the Defence Research Agency of the United Kingdom both in photonic bandgap effects and in the related field of quantum cryptography. - Possible applications such as very narrow band filters, thresholdless lasers,...