White Light Emission from Fluorescent SiC with Porous Surface

Abstarct We report for the first time a NUV light to white light conversion in a N-B co-doped 6H-SiC (fluorescent SiC) layer containing a hybrid structure. The surface of fluorescent SiC sample contains porous structures fabricated by anodic oxidation method. After passivation by 20 nm thick Al 2 O 3 , the photoluminescence intensity from the porous layer was significant enhanced by a factor of more than 12. Using a porous layer of moderate thickness (~10 µm), high-quality white light emission was realized by combining the independent emissions of blue-green emission from the porous layer and yellow emission from the bulk fluorescent SiC layer. A high color rendering index of 81.1 has been achieved. Photoluminescence spectra in porous layers fabricated in both commercial n-type and lab grown N-B co-doped 6H-SiC show two emission peaks centered approximately at 460 nm and 530 nm. Such blue-green emission phenomenon can be attributed to neutral oxygen vacancies and interface C-related surface defects generated dring anodic oxidation process. Porous fluorescent SiC can offer a great flexibility in color rendering by changing the thickness of porous layer and bulk fluorescent layer. Such a novel approach opens a new perspective for the development of high performance and rare-earth element free white light emitting materials.