PHOTOLUMINESCENCE STUDY OF POROUS 4H-SiC
S. Keraï, K. Ghaffour*
Laboratoire Matériaux et Energies Renouvelables,Département d’Electronique
Faculté des Sciences de l’Ingénieur, Université Abou Bakr Belkaîd,
B.P 230, Pôle Chetouane,13000 Algérie
* Corresponding author. E-mail : k_ghaffour @mail.univ-tlemcen.dz
Received : 08 January 2003; revised version accepted : 01 June 2003
Porous silicon carbide exhibits better luminescence properties than those of bulk SiC at room temperature. In this paper we study the low temperature (9k) photoluminescence (PL) of porous 4H-SiC obtained by electrochemical etching of a region of crystalline 4H-SiC in hydrofluoric solution. A yellow-green luminescence has been observed in the both structures i.e. porous and initial material. Their spectra present the same morphology with two band emission resolved. However, PL spectrum of the bulk SiC is greater than that of porous region. This could be explained by the anodization procedure that minimizes the density of defect states participating in the radiative recombination.
Keywords: Porous 4H-SiC; Photoluminescence; Anodization; Surface states.