In the past, pulsed electrically detected magnetic resonance experiments (pEDMR) with silicon dangling bonds (db) in hydrogenated microcrystalline silicon (mu c-Si:H) showed that at low temperatures, two db recombination mechanism,, exist where electrons are captured (i) by dbs directly (db-dc) or (ii) via band-tail states (tail-db). Here. similar experiments on hydrogenated amorphous silicon (a-Si:H) and crystalline silicon/silicondioxide interfaces (c-Si/SiO2) are presented. They show that at low temperatures, only the db-dc is detectable at dbs in the c-Si/SiO2 interface (Pb centers) while in a-Si:H, only tail-db processes are observed. (C) 2005 Elsevier B.V. All rights reserved.