CN100383275C - A kind of preparation method of gold-silver nanoparticle dispersed oxide optical film - Google Patents

Abstract

The present invention provides a method for preparing optical films of dispersal oxide with gold-silver nanometer particles, which belongs to the technical field of metal nanometer particles and inorganic non-metal material composite materials. Three sputtering targets of Au, Ag and the oxide are arranged in a sputtering device simultaneously, and shielding plates are respectively arranged in front of each sputtering target and a basal plate. Through the independent control of the deposition rate of metal and the oxide, the composite films of the dispersal oxide with the gold-silver pure-metal nanometer particles having the characteristics of nanometer layer shapes are prepared. The present invention comprises the specific steps that firstly, single-layer films of the Au or Ag nanometer particles are prepared; the oxide films are deposited; then, the single-layer films of the Au or Ag nanometer particles are deposited, and one layer of the oxide films are deposited. According to the sequences, alternating deposition is carried out, and the films of the dispersal oxide of the gold-silver pure-metal nanometer particles having layer structures can be manufactured. The present invention has the advantage that the present invention has good non-linear optical characteristics.

Description

A kind of preparation method of gold-silver nanoparticle dispersed oxide optical film

technical field

The invention belongs to the technical field of composite materials of metal nanoparticles and inorganic non-metallic materials, and in particular provides a design and preparation process of gold and silver pure metal nanoparticles dispersed oxide multilayer nonlinear optical film.

Background technique

Nano-metal particles dispersed oxide film, due to the surface effect and quantum size effect of metal nanoparticles are very significant, surface plasmon resonance occurs under the interaction of electrons and light near the surface of nano-metal particles, and selectively absorbs and transmits incident light waves. Pass. Functional thin films with such nonlinear optical properties have broad application prospects in the field of optical communications as optical wave splitters and optical switches.

In order to obtain strong nonlinear optical effects, it is generally achieved by changing the size, shape, dispersion concentration and microstructure of metal particles. Most of the systems currently studied are pure metal particles dispersed oxide films, such as (Au, Ag, Cu)/(SiO ₂ , TiO ₂ , Al ₂ O ₃ , MgF ₂ , BaTiO ₃ , Nd ₂ O ₃ , BaO, LiNbO ₃ , La ₂ O ₃ ), etc., the preparation techniques used include melt quenching method, ion implantation method, sol-gel method, sputtering method, etc. It is difficult to increase and control the volume fraction of metal dispersed particles by melting quenching method, ion implantation method, and sol-gel method; by using single target sputtering method, due to the large difference in the deposition rate of metal and oxide, it is difficult to increase the volume of metal particles Scores are also difficult. Recently, the applicant has made progress in the study of increasing the volume fraction of metal particles by using the multi-target magnetron sputtering method. By introducing a layered structure into the composite film, a wide range of control of the metal phase content has been achieved. The related preparation process has been Apply for a national patent [patent application number: 03156142.X]. Combined with the post-heat treatment process, the metal phase content of the precursor film with nano-layered characteristics can still have a good dispersion structure and surface plasmon resonance absorption peak when the metal phase content is as high as 85%. report on this result. However, our patent applications and research are limited to a gold nanoparticle or silver nanoparticle dispersed oxide system, and reports on gold-silver composite metal particle dispersed oxide films are relatively rare. The currently available reports on gold-silver composite nanoparticle dispersed oxide films include: Huazhong Shi, Lide Zhang and Weiping Cai: JOURNAL OF APPLIED PHYSICS, 87 [3] (2002) 1572-1574, they prepared by sol-gel method Ag _x Au _1-x /SiO ₂ (0.2<x<0.8) dispersed film, after 973K, 2h annealing treatment, Ag and Au form alloy particles, and a surface plasmon resonance absorption peak is observed in the optical absorption spectrum, with the Ag The position of the absorption peak red shifted from 524nm to 400nm with the increase of content; B.Prevel, J.Lerme, M.Gaudry, E.Cottancin, M.Pellarin, M.Treilleux, P.Melinon, A.Perez, JLVialle and M. Broyer: Scripta mater.44 (2001) 1235-1238, they prepared (Au _0.5 Ag _0.5 ) _N /Al ₂ O ₃ thin films by low-energy particle beam deposition technology, Ag and Au form alloy particles, and the absorption spectrum is at 420nm and 500nm An independent plasmon resonance absorption peak was observed; Xie Zibin, Wang Ququan, Zhou Zhengguo, Xiong Guiguang: Journal of Wuhan University, 45 [1] (1999) 84-86, they prepared Ag by radio frequency magnetron sputtering _x Au _1-x /SiO ₂ composite metal particle film, Au and Ag alloy particles were obtained after annealing, only one absorption peak appeared between 410nm and 537nm; Chen Haibo, Jiang Changzhong, Shi Ying, Fu Qiang: Functional Materials, 34 [6] 714-718, they implanted Ag and Au ions into SiO ₂ glass successively to obtain alloyed Au and Ag nanoparticles, and there was only one absorption peak in the light absorption spectrum. Conditions can adjust the position of the plasmon resonance absorption peak; in the above documents, the metal multi-element particles dispersed in the oxide film are all alloy particles, although the position of the plasmon resonance absorption peak will change, they are all one Independent plasmon resonance absorption peaks. In addition, Moskovits, Srnova-Sloufova and Vlckova: Journal of Chemical Physics, 116 (2002) 10435, using sol-gel coating technology to prepare Ag(Au) or Au(Ag) particles with core-shell structure, plasmon resonance The absorption peak is still characterized by an independent plasmon resonance absorption peak.

Contents of the invention

The object of the present invention is to provide a method for preparing an oxide optical film dispersed with gold and silver nanoparticles. Preparation of gold and silver nanoparticles dispersed oxide optical thin films by sputtering technique. The working gas pressure is low, the pollution to the film is less, the film forming quality is stable, the film forming speed can be precisely controlled, and it is suitable for the preparation of nanoscale particles and nano film.

In the current field of research on gold-silver composite nanoparticles dispersed oxide optical films, researchers can only obtain gold-silver alloy particles, and there is only one absorption peak in the light absorption spectrum. A multi-layer dispersion process designed by us can make gold and silver particles not in the form of alloy, but separately dispersed in the oxide in the form of pure metal, and the prepared film has two plasmon resonance absorption peaks in the optical absorption spectrum .

In the present invention, three sputtering targets of gold, silver and oxide are installed in the sputtering chamber at the same time, and shutters are respectively set in front of each sputtering target and substrate, and through the separate control of the deposition speed of gold, silver and oxide, In this way, the precise control of parameters such as the particle size, dispersion state, and film thickness of gold and silver particles can be realized, and a gold-silver nano-particle dispersed oxide composite optical film with nano-layered characteristics can be prepared. Specific process flow:

Au or Ag nano particle monolayer film is firstly prepared, then oxide film is deposited, then Au or Ag nano particle monolayer film is deposited, and then an oxide film is deposited. Alternate deposition according to the above sequence to form a layered structure film; Au or Ag nano particle monolayer films are separated by a layer of oxide film. This allows gold and silver to exist as pure metals without forming alloys.

The dispersed oxides described in the present invention are SiO ₂ , TiO ₂ , Al ₂ O ₃ , BaTiO _{3 ,} etc.; the diameter of gold and silver nano metal particles is 2-50 nm, and the dispersion is uniform; the thickness of the oxide layer is between 5-500 nm The composition of gold and silver is described by the chemical formula Au _x Ag _1-x /SiO ₂ , x represents the volume percentage of gold particles, which is between 5% and 85%; the film structure is composed of gold nanoparticle layer, silver nanoparticle layer and oxide layer alternating layered structure.

The preparation process parameters of the above-mentioned multilayer nonlinear optical film made of nano-metal particle materials are as follows: the film-forming substrate pressure is 1×10 ^-5 ~5×10 ^-4 Pa, the film-forming pressure is 0.1-1 Pa; the gold nanoparticle layer film-forming The process parameters are argon flow rate of 5-30 cubic centimeters per minute, oxygen flow rate of 5-10 cubic centimeters per minute, sputtering target power of 50-300W, high-frequency inductor coil power of 50-300W, and film-forming time of 50 ~300 seconds; silver nanoparticle layer film forming process parameters are argon flow rate of 5-30 cubic centimeters per minute, oxygen flow rate of 5-10 cubic centimeters per minute, sputtering target power of 50-300W, high-frequency inductor coil power 50-300W, film-forming time is 50-300 seconds; oxide nano-layer film-forming process parameters: argon flow rate is 5-30 cubic centimeters/minute, oxygen flow rate is 5-10 cubic centimeters/minute, sputtering target The power of the coil is 50-300W, the power of the high-frequency inductance coil is 50-300W, and the film-forming time is 5-60 minutes.

The treatment process of the present invention aims to directly realize the particle size, dispersion state, volume percentage and film thickness of the metal particles in the film-forming process without a heat treatment process through the separate control of the deposition speed of gold and silver nano-metal particles and oxides. Precise control of such parameters, and on the basis of the above, a gold-silver nanoparticle-dispersed oxide optical composite film with nano-layered characteristics was prepared.

The advantage of the present invention is that: the gold and silver nanoparticles dispersed oxide optical composite film prepared by the present invention has a nano-layered structure, and the two kinds of metal particles of gold and silver exist in the state of pure metal instead of the state of alloy, and the two kinds of particles of gold and silver exist in the state of alloy. The diameters are all in the range of 2-50nm, and the dispersion is uniform. Two absorption peaks can be observed in the absorption spectrum of the prepared thin film, which has excellent nonlinear characteristics.

Description of drawings

Fig. 1 is a schematic diagram of the nanometer metal particle dispersed oxide multilayer film designed in the present invention. Wedge 1 is the substrate, wedge 2 and wedge 3 are the Au or Ag nanoparticle layer, respectively, and wedge 4 is the oxide layer.

Fig. 2 is a cross-sectional transmission electron micrograph of gold and silver nanoparticles dispersed oxide multilayer film. Wedge 1 is a nano-Au particle layer, wedge 2 is a nano-Ag particle layer with a particle diameter of 6-8nm, wedge 3 is a _SiO2 layer with a thickness of about 10nm, and wedge 4 is a substrate.

Detailed ways

The _{AuxAg1 -x} / _SiO2 system gold-silver nanoparticle dispersed oxide multilayer film of the present invention is composed of several layers or even hundreds of layers of gold-silver nano-metal particle layers and oxides, and the diameter of the gold-silver nanoparticle is 2 ~50nm, the thickness of the oxide layer is several nanometers to tens of nanometers. Fig. 2 represents the cross-sectional transmission electron micrograph of the nano-layered morphology of the gold-silver multilayer film (wherein the Au nanoparticle layer is 3 layers, the Ag nanoparticle layer is 3 layers, and the SiO ₂ layer is 7 layers). As shown in Fig. 2, the nano metal particle layer is completely parallel and evenly spaced in a large area, and the thickness of the entire film is 70nm. The thickness of the _SiO2 layer is 10nm, and the diameter of the gold and silver nanoparticles is 6-8nm. The thin film is prepared by sputtering technique.

Its specific technological process is:

1. Au, Ag and SiO ₂ sputtering targets have a diameter of 50mm and a purity of 99.99%.

2. Clean the quartz substrate ultrasonically in acetone for 5-10 minutes, and then put it into the sputtering chamber.

3. After the substrate pressure in the sputtering chamber is less than 1×10 ^-6 ~ 5×10 ^-4 Pa, introduce oxygen and argon, and the flow rates are 5-10 cubic centimeters/minute and 5-30 cubic centimeters/minute, respectively. The film forming pressure is kept between 0.1-1Pa, and the power of the Au and Ag sputtering targets and the high-frequency inductance coil is set at 50-300W. The power of SiO ₂ sputtering target and high frequency inductance coil is set at 50-300W. Wait for the plasma to stabilize for 3 to 10 minutes.

4. Open the shutter in front of the Au or Ag sputtering target and the substrate, deposit the Au or Ag film, and the deposition time is 5-300 seconds. Then, close the shutter in front of the Au or Ag sputtering target and the substrate.

5. Open the shutter in front of the SiO ₂ sputtering target and the substrate, and deposit the SiO ₂ film, and the deposition time is 5 to 60 minutes. Then, close the shutter in front of the _SiO2 sputtering target and substrate.

6. Open the shutter in front of the Au or Ag sputtering target and the substrate, and deposit the Au or Ag film. The deposition time is 5-300 seconds. Then, close the shutter in front of the Au or Ag sputtering target and the substrate.

7. Repeat step 5.

8. Repeat steps (4) (5) (6) (7) to alternately deposit Au or Ag films and SiO ₂ films to prepare multilayer Au _x Ag _1-x /SiO ₂ films.

Table 1 has provided several preferred embodiments of the present invention:

Table 1 preferred embodiment

continued

In summary, the preparation process designed in the present invention can prepare gold and silver pure metal nanoparticles dispersed oxide multilayer nonlinear optical film with nano-layered structure.

Claims (1)

1. A gold-silver nanoparticle dispersed oxide optical film preparation method is characterized in that: three sputtering targets of Au, Ag and oxide are installed in the sputtering equipment simultaneously, and are respectively set before each sputtering target and substrate The shroud, through separate control of the deposition rate of metal and oxide, prepares a gold and silver pure metal nanoparticle dispersed oxide composite film with nano-layered characteristics; the specific steps are: first prepare Au or Ag nanoparticle monolayer film, and then Deposit an oxide film, then deposit an Au or Ag nanoparticle monolayer film, and then deposit an oxide film; the composition of gold and silver is controlled by the number of layers of the Au or Ag nanoparticle monolayer film. According to the above-mentioned alternate deposition mode, the Form a gold and silver pure metal nanoparticle dispersed oxide film with layered structure characteristics; the process parameters are: the film-forming substrate pressure is 1×10 ^-5 ~5×10 ^-4 Pa, the film-forming pressure is 0.1-1Pa; the gold nanoparticle layer The flow rate of argon gas in the film forming process is 5-30 cubic centimeters per minute, the flow rate of oxygen is 5-10 cubic centimeters per minute, the power of the sputtering target is 50-300W, the power of the high-frequency inductor coil is 50-300W, and the film-forming time is 50 ~300 seconds; silver nanoparticle layer film forming process parameters are argon flow rate of 5-30 cubic centimeters per minute, oxygen flow rate of 5-10 cubic centimeters per minute, sputtering target power of 50-300W, high-frequency inductor coil power 50-300W, film-forming time is 50-300 seconds; oxide nano-layer film-forming process parameters: argon flow rate is 5-30 cubic centimeters/minute, oxygen flow rate is 5-10 cubic centimeters/minute, sputtering target The power of the high-frequency induction coil is 50-300W, the power of the high-frequency inductor coil is 50-300W, and the film-forming time is 5-60 minutes; the oxides are SiO ₂ , TiO ₂ , Al ₂ O ₃ , BaTiO ₃ , Nd ₂ O ₃ , BaO, LiNbO ₃ , La ₂ O ₃ ; the diameter of gold nanoparticles is 2-50nm, and the dispersion is uniform; the diameter of silver nanoparticles is 2-50nm, and the dispersion is uniform; the thickness of the oxide layer is between 5-500nm; The composition is described by the chemical formula Au _x Ag _1-x /SiO ₂ , x represents the volume percentage of gold particles, between 5% and 85%; the film structure is an alternating layer composed of gold nanoparticle layers, silver nanoparticle layers and oxide layers shape structure.

Images