INTENSE VIOLET PHOTOLUMINESCENCE AT ROOM-TEMPERATURE IN AS-DEPOSITED A-SI-H-O FILMS

Three photoluminescence (PL) bands at similar to 355, similar to 415, and 740 nm were observed at room temperature in a-Si:H:O films fabrica ted by plasma-enhanced chemical vapor deposition without post-processi ng, The violet emission is intense and stable, and its intensity is cl osely related to the oxygen content in the films, which can be control led by the applied de bias on the sample substrates during deposition. The first two PL peaks are ascribed to oxygen-related color centers, and the last one to the quantum size effect of the crystallites embedd ed in a-Si:H:O matrix. (C) 1998 Elsevier Science B.V. All rights reser ved.