Visible and Infrared Luminescence and Applications of Er-doped AlN Thin Films

An Er³⁺-doped AlN film has been prepared by radio frequency magnetron sputtering and its photoluminescence (PL) characteristics were studied. It shows high PL efficiency in a wide range of the visible (540 and 560 nm) and infrared (817, 864, 980 and 1534 nm) ranges. In the transition of 4f levels of Er³⁺, the PL from ²H11/2 →⁴I15/2 and ⁴S3/2 → ⁴I15/2 shows obvious temperature dependence, which exhibits a functional relationship between their PL intensity ratio I540nm/I560nm and temperature over 100-550 K. It has a relatively high sensitivity (little above 0.01 K^-1) among the currently researched temperature sensing materials and can be used as a new contactless temperature sensor in a harsh environment. In the field of infrared luminescence, 864 and 1534 nm are the low loss transmission window in silica fibers and suitable for communication systems.