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Thin Films|13 Article(s)
Studies on the Preparation and Properties of Nanocrystalline ZnSX Thin Films by RF Magnetron Sputtering Technique at Room Temperature
Yang YANG, Gang LI, Kewu JING, Tianqi WANG, Saiao PENG, Tingting YAO, and Shuyong CHEN
In order to obtain high-performance transparent dielectric thin films， nanocrystalline zinc-rich ZnS films were prepared on glass substrates by radio frequency magnetron sputtering with a ZnS ceramic target at room temperature， and the effect of the radio frequency power on the structural， surface morphology and optical properties of the films were studied using X-ray diffraction， field emission scanning electron microscopy， micro-Raman spectroscopy， ultraviolet-visible spectroscopy and spectroscopic ellipsometry. It is found that the radio frequency power has an important impact on the phase formation and crystallinity of the ZnSX films. With the increase in the radio frequency power， the atomic ratio of zinc to sulfur， intensity of the characteristic Raman peak and refraction index first increase and then decrease， the optical band gap of the film deceases from 3.86 eV to 3.76 eV systematically. Among the various radio frequency power values investigated， 150 W is optimal for the growth of highly crystalline ZnSX films with the cubic phase， the ratio of Zn/S of film is 1.23 close to the standard stoichiometric ratio， the average transmittance is more than 80% at visible light， and the optical refractive index of ZnSX film is 2.03 at 550 nm. In order to obtain high-performance transparent dielectric thin films， nanocrystalline zinc-rich ZnS films were prepared on glass substrates by radio frequency magnetron sputtering with a ZnS ceramic target at room temperature， and the effect of the radio frequency power on the structural， surface morphology and optical properties of the films were studied using X-ray diffraction， field emission scanning electron microscopy， micro-Raman spectroscopy， ultraviolet-visible spectroscopy and spectroscopic ellipsometry. It is found that the radio frequency power has an important impact on the phase formation and crystallinity of the ZnSX films. With the increase in the radio frequency power， the atomic ratio of zinc to sulfur， intensity of the characteristic Raman peak and refraction index first increase and then decrease， the optical band gap of the film deceases from 3.86 eV to 3.76 eV systematically. Among the various radio frequency power values investigated， 150 W is optimal for the growth of highly crystalline ZnSX films with the cubic phase， the ratio of Zn/S of film is 1.23 close to the standard stoichiometric ratio， the average transmittance is more than 80% at visible light， and the optical refractive index of ZnSX film is 2.03 at 550 nm.
Acta Photonica Sinica
- Publication Date: Jul. 25, 2021
- Vol. 50, Issue 7, 230 (2021)
Thermochromic Film Based on VO2@SiO2 Core-shell Nanoparticles
Xin WANG, Wenjie HU, and Yao XU
A thermochromic film was prepared with VO2@SiO2 core-shell nanoparticles to enhance the visible light transmittance and weather resistance of thermochromic film and also decrease the agglomeration of VO2 nanoparticles prepared by thermal decomposition method. VO（OH）2@SiO2 core-shell nanoparticles were prepared by coating SiO2 layer on the surface of VO（OH）2 nanoparticles via the surface electric interaction between nagatively charged VO（OH）2 nanoparticles and positively charged NH2 groups of aminopropyltriethoxylsilane. Then a normal heat treatment of VO（OH）2@SiO2 under Ar atmosphere was utilized to obtain VO2@SiO2 nanoparticles. Subsequently optical film with good thermochromic property was prepared by coating the resin dispersion of VO2@SiO2 on well cleaned glass. The thermochromic property and the weather resistance of thermochromic film were studied . From TEM images， we find that SiO2 shell prevents the agglomeration of VO（OH）2 during heat treatment. Research on the optical properties of the film shows that the SiO2 and air of low refractive index can improve the optical properties of thermochromic films，and when the mass fraction of VO2@SiO2 nanoparticles is 10wt%， the optical performance of the composite film is the best. The protective effect of the SiO2 shell to the VO2 core obviously improves the oxidation resistance and corrosion resistance of VO2 in damp heating and acidic environment， which makes longer life of VO2 thermochromic film. A thermochromic film was prepared with VO2@SiO2 core-shell nanoparticles to enhance the visible light transmittance and weather resistance of thermochromic film and also decrease the agglomeration of VO2 nanoparticles prepared by thermal decomposition method. VO（OH）2@SiO2 core-shell nanoparticles were prepared by coating SiO2 layer on the surface of VO（OH）2 nanoparticles via the surface electric interaction between nagatively charged VO（OH）2 nanoparticles and positively charged NH2 groups of aminopropyltriethoxylsilane. Then a normal heat treatment of VO（OH）2@SiO2 under Ar atmosphere was utilized to obtain VO2@SiO2 nanoparticles. Subsequently optical film with good thermochromic property was prepared by coating the resin dispersion of VO2@SiO2 on well cleaned glass. The thermochromic property and the weather resistance of thermochromic film were studied . From TEM images， we find that SiO2 shell prevents the agglomeration of VO（OH）2 during heat treatment. Research on the optical properties of the film shows that the SiO2 and air of low refractive index can improve the optical properties of thermochromic films，and when the mass fraction of VO2@SiO2 nanoparticles is 10wt%， the optical performance of the composite film is the best. The protective effect of the SiO2 shell to the VO2 core obviously improves the oxidation resistance and corrosion resistance of VO2 in damp heating and acidic environment， which makes longer life of VO2 thermochromic film.
Acta Photonica Sinica
- Publication Date: Jul. 25, 2021
- Vol. 50, Issue 7, 220 (2021)
Influence of Substrate Temperature on Properties of ZnSe Thin Films Deposited by Electron-beam Evaporation
Guangyu ZHAO, Li XU, Jie FAN, Jiabin ZHANG, Yunping LAN, Yonggang ZOU, and Xiaohui MA
In order to study the influence of substrate temperature on the microstructure and optical properties of ZnSe thin films， a single layer of ZnSe thin films was prepared on K9 glass substrate by electron beam evaporation. By studying the X-ray diffraction spectrum， transmission spectrum characteristics， surface morphology and roughness of the thin film， the variation rules of the microstructure and optical properties of the thin film under different substrate temperatures were analyzed. The experimental results show that the ZnSe films prepared in the range of substrate temperature from 20℃ to 200℃ are all single crystal films with （111） crystallographic texture. With the increase of substrate temperature， the kinetic energy obtained by atoms on the substrate increases， resulting in the increase of grain size， internal strain and dislocation density of the films. The optical properties of thin films are also different at different substrate temperatures. With the increase of substrate temperature， the refractive index and extinction coefficient decrease， the optical band gap increases， and the surface roughness of thin films decreases. It is concluded that the decrease of refractive index is caused by the increase of the proportion of the pores in the film， and the decrease of extinction coefficient is caused by the increase of crystallinity and the reduction of internal defects. In order to study the influence of substrate temperature on the microstructure and optical properties of ZnSe thin films， a single layer of ZnSe thin films was prepared on K9 glass substrate by electron beam evaporation. By studying the X-ray diffraction spectrum， transmission spectrum characteristics， surface morphology and roughness of the thin film， the variation rules of the microstructure and optical properties of the thin film under different substrate temperatures were analyzed. The experimental results show that the ZnSe films prepared in the range of substrate temperature from 20℃ to 200℃ are all single crystal films with （111） crystallographic texture. With the increase of substrate temperature， the kinetic energy obtained by atoms on the substrate increases， resulting in the increase of grain size， internal strain and dislocation density of the films. The optical properties of thin films are also different at different substrate temperatures. With the increase of substrate temperature， the refractive index and extinction coefficient decrease， the optical band gap increases， and the surface roughness of thin films decreases. It is concluded that the decrease of refractive index is caused by the increase of the proportion of the pores in the film， and the decrease of extinction coefficient is caused by the increase of crystallinity and the reduction of internal defects.
Acta Photonica Sinica
- Publication Date: Jun. 25, 2021
- Vol. 50, Issue 6, 209 (2021)
Preparation and Photoelectrocatalytic Properties of WO3/Pt Composite Film
Yujian ZHOU, Xue YANG, Jikai YANG, Decai NIE, Shurui YU, Nan XIAO, Zhipeng HOU, Yiming ZHAO, Xin WANG, Guozheng WANG, Kewei HUAN, and Wenxin LIU
WO3 nano-rods were synthesized on the FTO substrate by hydrothermal method. Pt nanoparticles with different deposition time（40 s， 80 s， 120 s） was loaded onto WO3 nano-rods by an electrodeposition method to prepare WO3/Pt composite film photoanodes. Characterization of samples was conducted by scanning electron microscopy and X-ray diffraction， the results show that the WO3/Pt composite films have been synthesized. Diffuse reflectance spectra show that the WO3/Pt composite film has more strong absorption than pure WO3 nano-rods film. Electrochemical impedance spectroscopy shows that the WO3/Pt composite film enhances a charge transfer efficiency compared with pure WO3 nano-rods film. The photoelectric properties of the samples were obtained from the photocurrent and the photoelectric catalysis. The WO3/Pt composite film samples have higher photocurrent and photoelectric catalytic （PEC） activity than pure WO3， and the sample obtained by depositing for Pt nanoparticles at 80 s （WO3/Pt-80 s） has the highest photocurrent and photoelectric photoelectric catalytic activity. Meanwhile， the photoelectric catalytic activity of WO3/Pt-80s composite film is higher than direct photocatalysis or electric catalysis of WO3/Pt-80s composite film. WO3 nano-rods were synthesized on the FTO substrate by hydrothermal method. Pt nanoparticles with different deposition time（40 s， 80 s， 120 s） was loaded onto WO3 nano-rods by an electrodeposition method to prepare WO3/Pt composite film photoanodes. Characterization of samples was conducted by scanning electron microscopy and X-ray diffraction， the results show that the WO3/Pt composite films have been synthesized. Diffuse reflectance spectra show that the WO3/Pt composite film has more strong absorption than pure WO3 nano-rods film. Electrochemical impedance spectroscopy shows that the WO3/Pt composite film enhances a charge transfer efficiency compared with pure WO3 nano-rods film. The photoelectric properties of the samples were obtained from the photocurrent and the photoelectric catalysis. The WO3/Pt composite film samples have higher photocurrent and photoelectric catalytic （PEC） activity than pure WO3， and the sample obtained by depositing for Pt nanoparticles at 80 s （WO3/Pt-80 s） has the highest photocurrent and photoelectric photoelectric catalytic activity. Meanwhile， the photoelectric catalytic activity of WO3/Pt-80s composite film is higher than direct photocatalysis or electric catalysis of WO3/Pt-80s composite film.
Acta Photonica Sinica
- Publication Date: Mar. 25, 2021
- Vol. 50, Issue 3, 201 (2021)
Study on Passivation of Monocrystalline Silicon by Tandem Hydrogenated Amorphous Silicon Film
Yueke DING, and Shihua HUANG
Studies on the passivation of monocrystalline silicon wafers by using plasma enhanced chemical vapor deposition for the deposition of monolayer intrinsic hydrogenated amorphous silicon films show that increasing the hydrogen dilution ratio is beneficial to reducing the defects in the films and enhancing the passivation effect. Excessive hydrogen dilution ratio can lead to the epitaxial growth of amorphous silicon on the silicon wafer surface and reduce the passivation effect. Annealing results in the increase of the degree of crystallization of amorphous silicon and the reduce of passivation effect. Meanwhile， annealing improves the quality of thin films and changes the way of H bonding and enhances the passivation effect. Therefore， the best passivation effect of monolayer hydrogenated amorphous silicon can be obtained only at appropriate hydrogen dilution ratio and annealing temperature. In order to improve the passivation effect of amorphous silicon film on silicon wafer， tandem intrinsic amorphous silicon film with high and low hydrogen dilution ratio is used to passivate silicon wafer. Therefore， the epitaxial growth of amorphous silicon on the silicon wafer surface can be avoided by stacking amorphous silicon thin films with high hydrogen dilution ratio on the thin films with low hydrogen dilution ratio. In the annealing process， the hydrogen in the film with high hydrogen dilution ratio diffuses into the film with low hydrogen dilution ratio， effectively passivating the suspension bonds on the surface of amorphous silicon and monocrystalline silicon， and improving the interface quality of amorphous silicon/silicon wafer. After the tandem passivation of the silicon wafer， the effective minority carrier lifetime is 7.36 ms， and the implied open-circuit voltage is 732 mV. Studies on the passivation of monocrystalline silicon wafers by using plasma enhanced chemical vapor deposition for the deposition of monolayer intrinsic hydrogenated amorphous silicon films show that increasing the hydrogen dilution ratio is beneficial to reducing the defects in the films and enhancing the passivation effect. Excessive hydrogen dilution ratio can lead to the epitaxial growth of amorphous silicon on the silicon wafer surface and reduce the passivation effect. Annealing results in the increase of the degree of crystallization of amorphous silicon and the reduce of passivation effect. Meanwhile， annealing improves the quality of thin films and changes the way of H bonding and enhances the passivation effect. Therefore， the best passivation effect of monolayer hydrogenated amorphous silicon can be obtained only at appropriate hydrogen dilution ratio and annealing temperature. In order to improve the passivation effect of amorphous silicon film on silicon wafer， tandem intrinsic amorphous silicon film with high and low hydrogen dilution ratio is used to passivate silicon wafer. Therefore， the epitaxial growth of amorphous silicon on the silicon wafer surface can be avoided by stacking amorphous silicon thin films with high hydrogen dilution ratio on the thin films with low hydrogen dilution ratio. In the annealing process， the hydrogen in the film with high hydrogen dilution ratio diffuses into the film with low hydrogen dilution ratio， effectively passivating the suspension bonds on the surface of amorphous silicon and monocrystalline silicon， and improving the interface quality of amorphous silicon/silicon wafer. After the tandem passivation of the silicon wafer， the effective minority carrier lifetime is 7.36 ms， and the implied open-circuit voltage is 732 mV.
Acta Photonica Sinica
- Publication Date: Mar. 25, 2021
- Vol. 50, Issue 3, 194 (2021)
Light Trapping Enhancement of Composite Rough Surface ZnO:Al Gratings in Thin Film Silicon Solar Cells
Ren-chen LIU, Jing LU, He-ping CHENG, Zhao-ming LIANG, and Yang LIU
This paper discussed the influence of composite rough surface aluminum-doped zinc oxide (ZnO:Al) gratings on light trapping efficiency of thin film silicon solar cells. Rough surface was characterized by correlation length (lcor) and average height (have), and superimposed on a one-dimension sine ZnO:Al grating with 980 nm period and 160 nm groove depth. The short-circuit current was higher when front electrode AZO grating had smaller lcor and larger have. As lcor=0.01, short-circuit current raised with the increase of have value, from 21.93 mA/cm2 of have=0.05 to 23.80 mA/cm2 of have=0.80. When used as back electrode, the short-circuit current decreased with the increase of have, from 25.50 mA/cm2 of have=0.05 to 24.81 mA/cm2 of have=0.80. Composite rough surface ZnO:Al grating and non-rough surface ZnO:Al grating were fabricated by chemical etching and direct current sputter respectively. Reflectivity results showed that total reflection of composite rough surface ZnO:Al grating (8.3%) was 1.9% lower than that of non-rough surface ZnO:Al grating (10.2%), and specular reflection of composite rough surface ZnO:Al grating (4.7%) was 2.1% lower than that of non-rough surface ZnO:Al grating (6.8%). Rigorous coupled wave method was used to simulate reflection of ZnO:Al grating with and non- rough surface. Results further confirmed that composite rough ZnO:Al grating was more suitable for front electrode of thin film solar cells due to its better anti-reflection effect and could obtain a larger short-circuit current. Non-rough surface ZnO:Al grating could reflect more photons back to silicon absorption layer due to its higher reflection and was more suitable for back electrode. This paper discussed the influence of composite rough surface aluminum-doped zinc oxide (ZnO:Al) gratings on light trapping efficiency of thin film silicon solar cells. Rough surface was characterized by correlation length (lcor) and average height (have), and superimposed on a one-dimension sine ZnO:Al grating with 980 nm period and 160 nm groove depth. The short-circuit current was higher when front electrode AZO grating had smaller lcor and larger have. As lcor=0.01, short-circuit current raised with the increase of have value, from 21.93 mA/cm2 of have=0.05 to 23.80 mA/cm2 of have=0.80. When used as back electrode, the short-circuit current decreased with the increase of have, from 25.50 mA/cm2 of have=0.05 to 24.81 mA/cm2 of have=0.80. Composite rough surface ZnO:Al grating and non-rough surface ZnO:Al grating were fabricated by chemical etching and direct current sputter respectively. Reflectivity results showed that total reflection of composite rough surface ZnO:Al grating (8.3%) was 1.9% lower than that of non-rough surface ZnO:Al grating (10.2%), and specular reflection of composite rough surface ZnO:Al grating (4.7%) was 2.1% lower than that of non-rough surface ZnO:Al grating (6.8%). Rigorous coupled wave method was used to simulate reflection of ZnO:Al grating with and non- rough surface. Results further confirmed that composite rough ZnO:Al grating was more suitable for front electrode of thin film solar cells due to its better anti-reflection effect and could obtain a larger short-circuit current. Non-rough surface ZnO:Al grating could reflect more photons back to silicon absorption layer due to its higher reflection and was more suitable for back electrode.
Acta Photonica Sinica
- Publication Date: Jan. 01, 2020
- Vol. 49, Issue 9, 0931002 (2020)
Infrared Indium Oxide Hf-doped Transparent Conductive Films
Feng TIAN, Ran BI, Wen-yuan ZHAO, Feng-bo HAN, Ya-dan LI, Chuan-tao ZHENG, and Yi-ding WANG
High-quality indium Hf-doped oxide (IHfO) films were prepared on quartz and ZnSe substrates by RF magnetron sputtering and annealing. The doping ratio of In2O3:HfO2 was 98wt.%:2wt. %. The composition of the film and the photoelectric properties of the 3~5 μm infrared band were tested and analyzed. The effects of annealing temperature, film thickness and oxygen flow rate on the properties of the film were analyzed. The results of XRD, SEM and XPS show that the prepared IHfO film has the stereo-structure of indium oxide. The doping of germanium does not affect the growth direction of indium oxide, but it leads to the decrease of lattice spacing, and the new hybridization of germanium and indium electrons track. The FTIR test results show that the transmittance of IHfO film in the 3~5 μm band decreases with the increase of annealing temperature, and the film deposited on the ZnSe substrate has a more stable transmittance. When the film thickness is 100 nm, the average transmission rate in the 3~5 μm is around 68%. The Hall Effect test results show that with the increase of oxygen flow rate, the resistivity of IHfO film increases gradually, the carrier concentration decreases, and the Hall mobility changes little. The analysis shows that grain boundary scattering is the main factor affecting the mobility of IHfO film. The optimal resistivity of the film is 3.3×10-2Ω·cm when the oxygen flow rate is 0.3 sccm. Compared with the commercial visible-band Indium Tin Oxide (ITO) thin films, the IHfO thin films prepared in this paper can be better applied in gas detection, infrared guidance and other related fields in the 3~5 μm infrared band. High-quality indium Hf-doped oxide (IHfO) films were prepared on quartz and ZnSe substrates by RF magnetron sputtering and annealing. The doping ratio of In2O3:HfO2 was 98wt.%:2wt. %. The composition of the film and the photoelectric properties of the 3~5 μm infrared band were tested and analyzed. The effects of annealing temperature, film thickness and oxygen flow rate on the properties of the film were analyzed. The results of XRD, SEM and XPS show that the prepared IHfO film has the stereo-structure of indium oxide. The doping of germanium does not affect the growth direction of indium oxide, but it leads to the decrease of lattice spacing, and the new hybridization of germanium and indium electrons track. The FTIR test results show that the transmittance of IHfO film in the 3~5 μm band decreases with the increase of annealing temperature, and the film deposited on the ZnSe substrate has a more stable transmittance. When the film thickness is 100 nm, the average transmission rate in the 3~5 μm is around 68%. The Hall Effect test results show that with the increase of oxygen flow rate, the resistivity of IHfO film increases gradually, the carrier concentration decreases, and the Hall mobility changes little. The analysis shows that grain boundary scattering is the main factor affecting the mobility of IHfO film. The optimal resistivity of the film is 3.3×10-2Ω·cm when the oxygen flow rate is 0.3 sccm. Compared with the commercial visible-band Indium Tin Oxide (ITO) thin films, the IHfO thin films prepared in this paper can be better applied in gas detection, infrared guidance and other related fields in the 3~5 μm infrared band.
Acta Photonica Sinica
- Publication Date: Jan. 01, 2020
- Vol. 49, Issue 9, 0931001 (2020)
Preparation and Optoelectronic Properties of Semi-transparent Cu2O/ZnO Heterojunction
Jin-zhu LI, Ai-ling TIAN, Bing-cai LIU, Hong-jun WANG, and Xue-liang ZHU
In order to study the semi-transparent thin film solar cell with better material stability, use direct current magnetron sputtering technique to deposit cuprous oxide(Cu2O) thin film and zinc oxide(ZnO) thin film, forming the Cu2O/ZnO heterojunction. By using scanning electron microscope, X-ray diffractometer, raman spectrometer, thin film measurement instrument and solar simulator, the influence caused by Cu2O layer prepared under different Ar/O2 gas flow ratio on material properties, optical properties and photoelectric properties of heterojunction is studied. Results show that the Cu2O/ZnO heterojunctions produced under the certain Ar/O2 gas flow ratios have certain photoelectric conversion ability under the standard simulated sunlight of AM1.5, which can be used as the energy conversion unit of the semi-transparent solar cell. In order to study the semi-transparent thin film solar cell with better material stability, use direct current magnetron sputtering technique to deposit cuprous oxide(Cu2O) thin film and zinc oxide(ZnO) thin film, forming the Cu2O/ZnO heterojunction. By using scanning electron microscope, X-ray diffractometer, raman spectrometer, thin film measurement instrument and solar simulator, the influence caused by Cu2O layer prepared under different Ar/O2 gas flow ratio on material properties, optical properties and photoelectric properties of heterojunction is studied. Results show that the Cu2O/ZnO heterojunctions produced under the certain Ar/O2 gas flow ratios have certain photoelectric conversion ability under the standard simulated sunlight of AM1.5, which can be used as the energy conversion unit of the semi-transparent solar cell.
Acta Photonica Sinica
- Publication Date: Aug. 25, 2020
- Vol. 49, Issue 8, 0831003 (2020)
Study on Properties of Fluorine-oxide Composite Films
Yun-yun SHI, Jun-qi XU, and Jun-hong SU
SiO2/YF3 and TiO2/YF3 composite films were prepared by SiO2, YF3, TiO2 single-component materials respectively, the changes of optical, mechanical and laser damage resistance properties of the composite films were explored. Two kinds of fluorine-oxide composite films with a mixing molar ratio of 1:1 were prepared by controlling the deposition rate of the materials during evaporation through dual-source co-evaporation technique, the refractive index, extinction coefficient, transmission characteristics, surface morphology and roughness of the composite films were investigated, and laser damage resistance performance was studied. The results show that the refractive indexes of SiO2/YF3 and TiO2/YF3 composite films are 1.478 7 and 1.864 6(wavelength 550 nm) respectively, which are between the single-component materials(YF3 1.493 6, SiO2 1.465 1, TiO2 2.048 3), and all present normal dispersion distribution; the results of ZYGO interference measurement show that the stress value of SiO2/YF3 film is 1.9 GPa, which is larger than the 0.4 GPa of the single-component materials SiO2 and YF3 but less roughness; the stress value of TiO2/YF3 film is 0.8 GPa, which is smaller than the 3.9 GPa stress of TiO2 but larger than YF3, both of them show a more obvious stress adjustment effect. The laser-induced damage threshold of SiO2/YF3 composite film is 9.2 J/cm2, which is 2.2% higher than single-component SiO2 and 39.2% higher than YF3; the laser-induced damage threshold of TiO2/YF3 is 7.8 J/cm2, for the single-component TiO2 film, it increases by 85.6%, compared with YF3 by 17.4%. The fluorine-oxide composite films are deposited by dual-source co-evaporation technology with small absorption and adjustable film refractive index; SiO2/YF3 and TiO2/YF3 composite films are better than single-component materials in resisting laser damage; the doping of YF3 can significantly reduce the stress of the single TiO2 material, but the stress of SiO2/YF3 is larger than that of single-component SiO2 and YF3 films. SiO2/YF3 and TiO2/YF3 composite films were prepared by SiO2, YF3, TiO2 single-component materials respectively, the changes of optical, mechanical and laser damage resistance properties of the composite films were explored. Two kinds of fluorine-oxide composite films with a mixing molar ratio of 1:1 were prepared by controlling the deposition rate of the materials during evaporation through dual-source co-evaporation technique, the refractive index, extinction coefficient, transmission characteristics, surface morphology and roughness of the composite films were investigated, and laser damage resistance performance was studied. The results show that the refractive indexes of SiO2/YF3 and TiO2/YF3 composite films are 1.478 7 and 1.864 6(wavelength 550 nm) respectively, which are between the single-component materials(YF3 1.493 6, SiO2 1.465 1, TiO2 2.048 3), and all present normal dispersion distribution; the results of ZYGO interference measurement show that the stress value of SiO2/YF3 film is 1.9 GPa, which is larger than the 0.4 GPa of the single-component materials SiO2 and YF3 but less roughness; the stress value of TiO2/YF3 film is 0.8 GPa, which is smaller than the 3.9 GPa stress of TiO2 but larger than YF3, both of them show a more obvious stress adjustment effect. The laser-induced damage threshold of SiO2/YF3 composite film is 9.2 J/cm2, which is 2.2% higher than single-component SiO2 and 39.2% higher than YF3; the laser-induced damage threshold of TiO2/YF3 is 7.8 J/cm2, for the single-component TiO2 film, it increases by 85.6%, compared with YF3 by 17.4%. The fluorine-oxide composite films are deposited by dual-source co-evaporation technology with small absorption and adjustable film refractive index; SiO2/YF3 and TiO2/YF3 composite films are better than single-component materials in resisting laser damage; the doping of YF3 can significantly reduce the stress of the single TiO2 material, but the stress of SiO2/YF3 is larger than that of single-component SiO2 and YF3 films.
Acta Photonica Sinica
- Publication Date: Aug. 25, 2020
- Vol. 49, Issue 8, 0831002 (2020)
Structure and Luminescence Properties of Eu3+ and Dy3+ Co-implanted AlN Films
Hai MA, Xiao-dan WANG, Xiang LI, Dan WANG, Hong-min MAO, and Xiong-hui ZENG
Dy3+ and Eu3+ ions with different doses were implanted into AlN thin films grown by hydride vapor phase epitaxy method. For Dy doped AlN, results of X-ray diffraction and Raman scattering show that the compressive stress of the sample increases with the increase of Dy3+ dose. When the Dy3+ dose increases from 5×1014 at/cm2 to 1×1015 at/cm2, the compressive stress of samples is close to saturation. For Dy3+ and Eu3+ co-doped AlN, according to the cathodoluminescence spectra, a possible energy transfer process between Dy3+ and Eu3+ is proposed. In addition, through changing the dose ratio of Dy3+ respect to Eu3+ ions, the chromaticity coordinates and color temperatures of Dy3+ and Eu3+ co-doped AlN can be effectively regulated. Dy3+ and Eu3+ ions with different doses were implanted into AlN thin films grown by hydride vapor phase epitaxy method. For Dy doped AlN, results of X-ray diffraction and Raman scattering show that the compressive stress of the sample increases with the increase of Dy3+ dose. When the Dy3+ dose increases from 5×1014 at/cm2 to 1×1015 at/cm2, the compressive stress of samples is close to saturation. For Dy3+ and Eu3+ co-doped AlN, according to the cathodoluminescence spectra, a possible energy transfer process between Dy3+ and Eu3+ is proposed. In addition, through changing the dose ratio of Dy3+ respect to Eu3+ ions, the chromaticity coordinates and color temperatures of Dy3+ and Eu3+ co-doped AlN can be effectively regulated.
Acta Photonica Sinica
- Publication Date: Aug. 25, 2020
- Vol. 49, Issue 8, 0831001 (2020)
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