Deep level energy states in porous silicon and porous silicon carbide determined by space-charge-limited current measurements

We determined the density of states distribution near the Fermi level both fox porous silicon (PS) and for porous silicon carbide (PSC) from the analy sis of the current-voltage (J-V) characteristics in the space-charge-limite d current (SCLC) regime. The distribution of deep level energy states of PS can be described by a stretched exponential function, whereas that of PSC exhibits a simple exponential shape. Theoretical analysis well explains the J-V characteristics of both porous materials, which suggests that the curr ent flow is entirely controlled by localized states situated at the quasi-F ermi level. (C) 1999 Elsevier Science B.V. All rights reserved.