Optical excitation of Er3+ ions in a-SiN alloys

Photoluminescence excitation spectroscopy was carried out on the I13/24→4I15/2 transition from Er-doped amorphous silicon–nitrogen thin film alloys (a-SiN). The sample was prepared by cosputtering of a Si target partially covered with Er pellets. It is demonstrated that Er3+ ions may be excited by direct sharp-line intra-4f-shell absorption as well as by energy transfer from the a-SiN matrix. The effects of temperature and possible energy transfer mechanisms to Er ions are presented and discussed.