Photonic crystals is one of the hottest scientific topics today. A photonic crystal could make it possible to manipulate light in much the same way as we handle electrons in a semiconductor crystal. Realization of photonic crystals in semiconductors would open the way towards photonic integration with ensuing increases in functionality and compactness. Our primary fabrication technology for two-dimensional photonic crystal devices is by dry etching nanometer sized holes in a semiconductor slab, developed both for deeply etched photonic crystals and for membranes. The group is a pioneer in deep-etching of photonic crystals in InP-based structures and has demonstrated several devices or device-concepts such as lasers, filters, negative-refraction etc. The group has also made significant contributions on the understanding of the physical mechanisms in nanofabrication of photonic crystals and its implication on electrical conduction and carrier-lifetimes.
Nanophotonics for energy is an emerging field. The need for efficient light generation and light harvesting devices will continue to be a major driving force both for research and for business. Our research focuses on the investigations of new concepts in light-matter interaction together with disruptive technologies for efficient photovoltaic and light emitters. This includes research on nano-wire/nano-pillar solar cells in III-Vs and Si, low-cost nanostructuring methods and plasmonic solar cells.
With increasing complexity and decreasing dimensions of structures the need for advanced characterization is obvious. Methods to spatially map with nanoscale lateral resolution a whole range of electrical and optical properties of devices have to be developed. We have focused on scanning probe techniques, in particular scanning capacitance microscopy (SCM), scanning spreading resistance microscopy (SSRM) and Kelvin force probe microscopy techniques for nanoscale characterization of the electrical properties of materials and devices. In addition, the a whole range of structural, optical, and electrical characterization tools such as high resolution x-ray diffraction, electron microcopies, micro-PL, micro-Raman etc are continuously refined and applied to all of the project areas mentioned above.