Broad excitation of Er luminescence in Er-doped HfO 2 films
In this paper, we investigated the broad sensitized luminescence properties of the Er-doped HfO2 films synthesized by pulsed laser deposition and ion implantation techniques, focusing on the mechanism of energy transfer in host matrix. The characteristics of photoluminescence (PL) in the Er-doped and undoped HfO2 films were analyzed with varied measuring temperatures. Based on the PL and PL excitation (PLE), we proposed that the O vacancy defects, ion implantation induced defects and Hf can act as sensitizers, which results in the broad band excitation of Er luminescence at 1540 nm. Cathode-luminescence (CL) measurements with hot electrons excitation show more features of the samples, and provide detailed information for the energy transfer and relaxation process.