Effect of deposition method on the optical and microstructural properties of vacuum-deposited MgF2 thin films

Acta Metall. Sin. (Engl. Lett.)

et al. 2016

The chemical structures, optical properties and laser-induced damage thresholds of magnesium fluoride films annealed at different temperatures were investigated. The results showed that the stoichiometry of MgF 2 film changed a little with the increase in annealing temperature. Analysis of the optical properties indicated that excellent antireflection behavior of the film in the range of 200-400 nm can be obtained by the samples coated with MgF 2 film. The refractive index increased and the extinction coefficient decreased with increasing annealing temperature. Compared with the asdeposited films, the laser-induced damage threshold was improved after annealing process and decreased with the increase in annealing temperature, which was probably due to the denser film and more absorption centers under higher annealing temperature.

“…The F 1s peak and the O 1s peak (Fig. 2b, c) were located at 686.5 and 530.4 eV, respectively, corresponding to Mg-F bonds and Mg-O bonds [1,11].…”

Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Annealing Effects on Structural, Optical Properties and Laser-Induced Damage Threshold of MgF2 Thin Films

Tan

Acta Metall. Sin. (Engl. Lett.)

et al. 2016

“…Cid, et al [6] deposited MgF 2 /ZnS bilayer film on the surface of Si solar cell with vacuum evaporation, and successfully prepared broadband antireflection film. Jahanbakhsh, et al [7] deposited MgF 2 on the glass substrate with electron beam evaporation and found that the measured spectrum of the sample was relatively consistent with that of the theory, and the film had the effect of increasing transmittance in the band of 400-1000 nm. Hannes, et al [8] prepared MgF 2 sol at low temperature, and deposited the sol on glass to get porous MgF 2 film, of which refractive index measured by ellipsometry was 1.38, in good agreement with that of the MgF 2 bulk crystal.…”

mentioning

confidence: 63%

Sputtering Power on the Microstructure and Properties of MgF₂ Thin Films Prepared with Magnetron Sputtering

Zhao

Journal of Inorganic Materials

et al. 2020

To reduce the F deficiency defect in MgF 2 thin films deposited with magnetron sputtering, SF 6 was added to the working gas Ar 2 as the reactive gas, and MgF 2 thin films were prepared on quartz glass substrates with radio frequency (RF) magnetron sputtering. The effects of sputtering power on the chemical compositions, microstructure and optical properties of MgF 2 thin film were investigated. The results show that with sputtering power increase from 115 to 220 W, the atomic ratio of F to Mg increased continuously, and reached 2.02 at 185 W, close to ideal stoichiometric ratio of 2 : 1. The crystallinity of MgF 2 film improved first, then decreased, and finally changed into amorphous state. Profile of particles composing MgF 2 film became clearer at first, and finally became blurred. Refractive index of MgF 2 film decreased firstly and then increased, and got the lowest value at 185 W, 1.384 at 550 nm wavelength which is very close to that of MgF 2 bulk crystal. The integral transmittance of the coated glass within 300-1100 nm (hereinafter referred to as the transmittance of the thin film) increased first and then decreased, and reached 94.99% at 185 W, higher than that of the bare glass substrate by 1.79%.

“…Cid et al deposited MgF 2 /ZnS bilayer film on the surface of silicon solar cell with vacuum evaporation, and successfully prepared broadband antireflection film [8]. Jahanbakhsh et al deposited MgF 2 on the glass substrate with electron beam evaporation and they found that the measured spectrum of the sample was relatively consistent with the theory, and the film had the effect of increasing transmittance in the band of 400-1000 nm [9]. Gholampour et al deposited MgF 2 /ZnS thin films on ZnS substrates by physical vapor deposition (PVD), the three-layer film of MgF 2 /ZnS/MgF 2 increased the average transmittance of the double-side coated sample in the wavelength range of 8-12 μm by about 26% [10].…”

Section: Introductionmentioning

confidence: 93%

Preparation of wide optical spectrum and high antireflection MgF₂ thin film with SF₆ as reactive gas

Zhao

et al. 2020

Mater. Res. Express

In order to suppress F-deficiency, SF 6 was added into the working gas Ar 2 as the reaction gas to deposit MgF 2 thin film on quartz glass substrate with radio frequency (RF) magnetron sputtering, and the effects of working pressure on the chemical compositions, microstructure and property of MgF 2 thin film were investigated. The results show that with the working pressure increase from 1.0 to 2.5 Pa, the atomic ratio of F: Mg decreased continuously, and reached 2.02 at 2.0 Pa, very close to the ideal stoichiometric ratio of 2:1; the crystallinity of MgF 2 film improved first then decreased, and finally changed into amorphous state; the particles' profile of MgF 2 film became clearer and their size increased significantly at first, but finally their profile became blurred. The refractive index of MgF 2 film decreased first and then increased, and got the lowest value at 2.0 Pa, 1.384, almost equal to that of MgF 2 bulk crystal. The transmittance of the coated glass within 300-1100 nm (hereinafter referred to as the transmittance of the thin film) increased first and then decreased. The transmittance of all films was higher than that of the bare glass substrate (93.2%), that is to say, all films had antireflection effect. The film transmittance reached 94.99% at 2.0 Pa, higher than that of the bare glass substrate by 1.79%, and higher than the simulated value calculated with G-Solver software by about 0.5%.