Effect of annealing treatment on Nd-SiO x thin film properties

Abstract

The series of Nd 3+ -doped Si-rich SiO 2 thin films with different excess Si content were deposited by magnetron co-sputtering of three different (SiO 2 , Si and Nd 2 O 3 ) targets under a plasma of pure argon at 500 °C. The Si excess content in the samples was monitored via a power applied on Si cathode. The films were submitted to the rapid thermal annealing (RTA) at 900, 1000 and 1100 °C, respectively. It was observed a phase separation and a formation of Si nanoclusters embedded in oxide host. The Si excess, remaining after a RTA-1100 °C annealing, was found to be negligible, confirmed nearly complete phase separation. The Nd 3+ photoluminescence (PL) property was explored as a function of Si excess and/or annealing temperature. The most efficient Nd 3+ PL emission was found for the samples with about 4.7% of Si excess. These optimal samples, submitted to RTA-900 °C-1 min treatment and conventional annealing at 900°C for 1 h in nitrogen flow, demonstrated comparable Nd 3+ PL intensities. This offers future application of RTA treatment to achieve an efficient emission from the materials doped with rare-earth ions.