Green light emission at room temperature was achieved from nonhydrogenated amorphous silicon–nitrogen (a-SiN) thin films. The films were deposited by cosputtering a silicon target covered with metallic erbium platelets in anAr+N2atmosphere. According to the deposition conditions, the nitrogen concentration [N] reached∼40 at. &percent;rendering an optical gap of approximately 3.5 eV while the Er concentration [Er] was estimated to be∼10 at. &percent;in the present films. The high [Er] associated to the optical band gap allows the direct excitation ofEr3+ions. This optical excitation is more efficient at low temperatures as a consequence of the reduction in nonradiative processes, and when exciting the samples with the 488.0 nm line of anAr+laser which is in resonance with the4F7/2Er3+energy level. In addition to light emission at∼520and∼545 nm,transitions in the infrared energy region could be easily verified in as-deposited samples. ©1998 American Institute of Physics.