Novel Photonic Applications of Silicon Carbide

International audienceSilicon carbide (SiC) is emerging rapidly in novel photonic applications thanks to its unique photonic properties facilitated by the advances of nanotechnologies such as nanofabrication and nanofilm transfer. This review paper will start with the introduction of exceptional optical properties of silicon carbide. Then, a key structure, i.e., silicon carbide on insulator stack (SiCOI), is discussed which lays solid fundament for tight light confinement and strong light-SiC interaction in high quality factor and low volume optical cavities. As examples, microring resonator, microdisk and photonic crystal cavities are summarized in terms of quality (Q) factor, volume and polytypes. A main challenge for SiC photonic application is complementary metal-oxide-semiconductor (CMOS) compatibility and low-loss material growth. The state-of-the-art SiC with different polytypes and growth methods are reviewed and a roadmap for the loss reduction is predicted for photonic applications. Combining the fact that SiC possesses many different color centers with the SiCOI platform, SiC is also deemed to be a very competitive platform for future quantum photonic integrated circuit applications. Its perspectives and potential impacts are included at the end of this review paper

Review of Sublimation Growth of SiC Bulk Crystals

The review on bulk growth of SiC includes a basic overview on the widely used physical vapor transport method for processing of 4H-SiC boules as well as the discussion of three current research topics: (a) Sublimation bulk growth of large area, freestanding cubic SiC, (b) in-situ Visualization of the PVT Process using 2D and 3D X-ray based imaging and (c) prediction of dislocation formation and motion in SiC using a continuum model of dislocation dynamics (CDD)

New Approaches and Understandings in the Growth of Cubic Silicon Carbide

In this review paper, several new approaches about the 3C-SiC growth are been presented. In fact, despite the long research activity on 3C-SiC, no devices with good electrical characteristics have been obtained due to the high defect density and high level of stress. To overcome these problems, two different approaches have been used in the last years. From one side, several compliance substrates have been used to try to reduce both the defects and stress, while from another side, the first bulk growth has been performed to try to improve the quality of this material with respect to the heteroepitaxial one. From all these studies, a new understanding of the material defects has been obtained, as well as regarding all the interactions between defects and several growth parameters. This new knowledge will be the basis to solve the main issue of the 3C-SiC growth and reach the goal to obtain a material with low defects and low stress that would allow for realizing devices with extremely interesting characteristics.Funding Agencies|European UnionEuropean Commission [720827]</p

How do regulated and voluntary carbon-offset schemes compare?

The Kyoto Protocol's Clean Development Mechanism (CDM) has become a key instrument for climate change mitigation. Parties with emission targets are using it to buy greenhouse gas (GHG) emission reductions for compliance against the Protocol's emission reduction targets. In parallel, the purchase of emission reductions through a voluntary carbon market has become a mainstream practice across business and individuals who, although not having any regulatory mandate, aim to offset their emissions. This voluntary market relies on mitigation projects which may or may not follow the standards of the CDM. This review compares these two instruments and traces similarities and differences in terms of project types, offset quality and contribution to sustainable development. It is shown that both mechanisms support a wide range of mitigation options and technologies, and differ considerably in the contribution of forestry and industrial gas offsets to their markets. There is not enough empirical data to assess the actual additionality and quality of produced offsets and their contribution to national and local sustainable development also requires further empirical assessment. Large scale mitigation options provide a substantial percentage of GHG reductions in both markets, with methane-based mitigation and fuel switching dominating over renewable investments such as solar and tidal. Africa remains the least benefited continent in both schemes. The review supports proposals towards reforming the CDM so that the least developed countries can also participate in a transition towards a decarbonised global society. Voluntary markets, in turn, are likely to remain driven by investors' willingness to support projects which are in line with poor countries' demands and priorities