GREEN PHOTOLUMINESCENCE FROM ER-CONTAINING AMORPHOUS SIN THIN-FILMS

Green light emission at room temperature was achieved from nonhydrogen ated amorphous silicon-nitrogen (a-SiN) thin films. The films were dep osited by cosputtering a silicon target covered with metallic erbium p latelets in an Ar+N-2 atmosphere. According to the deposition conditio ns, the nitrogen concentration [N] reached similar to 40 at. % renderi ng an optical gap of approximately 3.5 eV while the Er concentration [ Er] was estimated to be similar to 10 at. % in the present films. The high [Er] associated to the optical band gap allows the direct excitat ion of Er3+ ions. This optical excitation is more efficient at low tem peratures as a consequence of the reduction in nonradiative processes, and when exciting the samples with the 488.0 nm line of an Ar+ laser which is in resonance with the (F7/2Er3+)-F-4 energy level. In additio n to light emission at similar to 520 and similar to 545 nm, transitio ns in the infrared energy region could be easily verified in as-deposi ted samples. (C) 1998 American institute of Physics.