Novel Fluorescent Silicon Carbide Growth Approach for White LEDs

The primary objective of the project, laboratory growth of the novel fluorescent silicon carbide (f-SiC) crystal using the liquid phase epitaxial (LPE) technology, has been successfully achieved. The f-SiC is one of the key materials for the fabrication of the novel monolithic white light-emitting diode (LED). The largest contribution to global greenhouse gas (GHG) abatement comes from energy efficiency, which is responsible for 49% of the savings in 2030, according to IEA special report in 2015. The project has explored the advanced LPE method to produce the f-SiC crystals in an environmental friendly way. The Al-N co-doped silicon carbide crystalline thin layer has been successfully grown on the 6H-SiC substrate. The room-temperature photoluminescence spectroscopy and the optical microscope examinations carried out at Department of Photonics Engineering, Technical University of Denmark, shown blue- and white-light emissions of the f-SiC samples. It is expected to save up at least 10-20% of energy for the f-SiC growth. It also provides the opportunity for the Norwegian research institutes in promoting the research with internationally leading scientific qualities and innovative research activities.

The research project will focus on the fundamental study on the growth of the novel fluorescent silicon carbide crystals by the liquid solution phase epitaxial technology. The LPE method is able to grow the Al-N co-doped monocrystalline SiC. The project will be carried out with respect to the following two parts: 1.Laboratory investigation of the LPE growth of Al-N co-doped SiC crystals, including: (i) The configurations of solution epitaxy growth setup, the optimization of the key experimental growth parameters such as growth rate (productivity), and controlling of defect density, surface morphology (quality) and donor impurity distributions will be the main subjects of the experimental studies. (ii) Advanced characterization techniques, i.e. transmission electron microscopy, Raman spectroscopy and secondary ion mass spectroscopy etc., will be used to characterize the samples and to reveal the influence of key growth parameters. (iii) Theoretical simulations will be used to promote the understanding of laboratory studies. Mesoscale modelling based on thermodynamic and fluid dynamic understandings of the LPE process will be implemented in the designing the experimental setup as well as in the optimization of the SiC growth conditions. 2.The laboratory grown Al-N co-doped SiC samples will be further optically characterized by photoluminescence efficiency measurements in order to examine the feasibility for the fabrication of monolithic white LED.