Room temperature luminescence of Er doped nc-Si/SiO2 superlattices

Amorphous Si/SiO2 superlattices with a 80 nm top oxide are implanted with v arious erbium doses (1.2 x 10(15-5.2) x 10(16) cm(-2)). The effect of Si na nocrystals in the vicinity of the Er ions is investigated. We found that th e luminescence intensity is increased compared to an a-SiO2 film implanted with the same erbium dose. The Si layers are completely crystallized with a n average crystal size of 5.7 nm after annealing at 800 degrees C. Room tem perature luminescence is found at 1.54 mu m, and the intensity scales with the annealing time. Increasing the implantation dose decreases the room tem perature luminescence intensity. Over the whole range of 7-300 K the lumine scence quenches below one order of magnitude. Luminescence at 2, 2.55 and 3 .0 eV is assigned to interface defects at the nanocrystal surface and to im plantation damage in the SiO2. (C) 2000 Elsevier Science B.V. All rights re served.