LUMINESCENCE OF RARE EARTH DOPED Si/ZrO_2 CO-SPUTTERED FILMS

摘要

Er~(3+), Nd~(3+) and Tm~(3+) doped Si/ZrO_2 thin films have been prepared by rf co-sputtering. The films are 5 inches long and divided into 50 sections or positions, labeled from P1 to P50. The target configuration is such that the main target is ZrO_2 (181.46 cm~2), the rare earth (RE) oxide pellet (1.43 cm~2) is placed on the main target below the middle of section of the film and the Si chip (6.67 cm~2 or 6.00 cm~2) is placed on the main target below one end of the film (P40 to P50). The films were annealed to 700℃. The Er~(3+) ~4I_(13/2) → ~4I_(15/2) emission was detected but no ~4I_(11/2) → ~4I_(15/2) emission was detected. The ~4I_(13/2) → ~4I_(15/2) emision shows a narrow peak at 1527 nm (FWHM = 6.5 nm for P20) with two weaker side bands from 1430 nm to 1500 nm and from 1550 nm to 1600 nm. The Nd~(3+) ~4I_(3/2) → ~4I_(9/2), ~4I_(3/2) → ~4I_(11/2), and ~4I_(3/2) → ~4I_(13/2) emissions were detected being the ~4I_(3/2) → ~4I_(11/2) peaked at 1065 nm (FWHM = 39.5 nm for P30) the strongest. The ~4I_(3/2) → ~4I_(9/2) emission is relatively weak, less than one-fourth the peak intensity of the ~4I_(3/2) → ~4I_(11/2) emission but is broad (FWHM = 92 nm for P30). No Er~(3+) ~4I_(13/2) → ~4I_(15/2) emission or Nd~(3+) ~4F_(3/2) emissions were detected for the Si rich ends of the respective films, being the emission stronger from the Si poor end of the film towards the middle of the film. The maximum Er~(3+) ~4I_(13/2) → ~4I_(15/2) emission is for P20 and the maximum peak intensity for the Nd~(3+) ~4I_(3/2) → ~4I_(11/2) emission is for P30. The excitation wavelength dependence behavior for the Nd~(3+) ~4I_(3/2) → ~4I_(11/2) emission is that typical of energy transfer from the Si nanoparticles to the emitting Nd~(3+) ions. The excitation wavelength behavior for the Er~(3+) ~4I_(13/2) → ~4I_(15/2) emission reflects a mix of energy transfer from the Si nanoparticles and strong absorption for excitation wavelengths of 488.0 nm and 514.5 nm. The Tm~(3+) doped Si/ZrO_2 thin film does not exhibit infrared (IR) PL from the ~3H_4 → ~3F_4 emission or the ~3F_4 → ~3H_6 emission. The intense band from 500 nm to 800 nm observed for all of the RE doped Si/ZrO_2 films, due to defects in ZrO_2, barely permits the detection of the Tm~(3+) ~3H_4 → ~3H_6 emission which is best observed for P35.