Layers of p-type porous SiC were fabricated by anodization of resistive p-type 6H-SiC samples using HF/ethylene glycol solution. Thin films of lithium and aluminium as donor and acceptor elements were vacuum-deposited and diffused onto SiC substrates prior to anodization. The aim here was to investigate the properties of the nanoporous SiC layer formed by this method and to deduce the effect of diffused lithium as donor and Al as acceptor atoms on their photoluminescence response. The profile distribution of lithium and aluminium diffused atoms was carried out using secondary ion mass spectrometry. The photoluminescence spectra of the anodized Al-diffused samples exhibited a broad emission band centered at about 475nm, while the Li-diffused samples exhibited luminescence with one broad peak located at 655nm, attributed to Li-related defect centers. In addition, the photoluminescence intensity of lithium-diffused samples varied with the etching time.

Effect of Metal Diffusion into Polycrystalline 6H-SiC Prior to its Anodization on Luminescence Response. A.Cheriet, A.Keffous, L.Guerbous, Y.Belkacem, M.Kechouane, H.Menari: Superlattices and Microstructures, 2012, 51[5], 563-70