Fe-doped GZO transparent conductive film and preparation method and application thereof

Abstract

The invention discloses a Fe-doped GZO transparent conductive film and a preparation method and application thereof. The invention belongs to the field of transparent conductive films. The invention aims to provide a Fe-doped GZO transparent conductive film as well as a preparation method and application thereof. The method comprises the following steps: firstly, carrying out presintering, pressing and secondary sintering on Fe2O3 powder, Ga2O3 powder and ZnO powder to prepare a composite ceramic target material; and then the composite ceramic target is used as a sputtering target, deposition is carried out on the surface of a substrate through magnetron sputtering, annealing treatment is carried out in a nitrogen atmosphere after deposition is finished, and the Fe-doped GZO transparent conductive thin film is obtained. According to the method, low-cost replacement of ITO can be achieved, the resistivity and the light transmittance of the Fe-doped GZO transparent conductive thin film can be effectively improved, the method can be applied to photoelectric devices, and low-cost and large-area production is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of transparent conductive films, and particularly relates to an Fe-doped GZO transparent conductive film, a preparation method thereof and an application thereof. Background Art

[0002] A transparent conductive film is a thin film material with a wide bandgap, high visible light transmittance and low resistivity, and is widely used in energy-saving glass, liquid crystal displays, and optoelectronic devices. Among them, indium tin oxide (ITO) has a resistivity as low as 10 -4 -10 -5 Ω·cm, and the average visible light transmittance > 85%. The technology is relatively mature and widely used in the industry. However, the scarcity of indium and tin resources, the toxicity of indium, and the large brittleness of the film limit its application in flexible electronics.

[0003] Zinc oxide (ZnO) is a wide bandgap semiconductor material (~3.37 eV). ZnO has more grain boundary scattering. When undoped, its resistivity is about 10 -1 -10 2 Ω·cm. The resistivity of AZO (aluminum-doped zinc oxide) can be reduced to 10 -3 -10 -4 Ω·cm, and it is expected to become an important alternative material for ITO. However, in a humid and hot environment, Al 3+ may precipitate from the lattice position, and excessive Al doping is prone to segregation, forming an insulating phase, resulting in a decline in film quality and conductivity. GZO (gallium-doped zinc oxide) can better reduce the resistivity and improve the transmittance. However, the cost of Ga element is relatively high. Therefore, there is an urgent need to develop a transparent conductive film with excellent comprehensive performance and low cost and its preparation process. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an Fe-doped GZO transparent conductive film, a preparation method thereof and an application thereof. This method can achieve a low-cost replacement of ITO. The resistivity and transmittance of the Fe-doped GZO transparent conductive film can be effectively improved, and it can be applied to energy-saving glass and optoelectronic devices to achieve low-cost and large-area production.

[0005] The technical solution of the present invention is as follows:

[0006] One of the purposes of the present invention is to provide a preparation method of an Fe-doped GZO transparent conductive film, and the method is carried out according to the following steps:

[0007] S1: Grind Fe2O3 powder, Ga2O3 powder and ZnO powder with acetone, first perform pre-sintering, then grind and press again, and then perform secondary sintering to make a composite ceramic target;

[0008] S2: Using the composite ceramic target as the sputtering target, deposition is performed on the substrate surface by magnetron sputtering. After the deposition, the Fe-doped GZO transparent conductive film is obtained by annealing in a nitrogen atmosphere.

[0009] It is further defined that the composite ceramic target in S1 has a Fe2O3 powder content of 1-4 wt%, a Ga2O3 powder content of 1-4 wt%, and the balance is ZnO powder.

[0010] It is further defined that the ZnO powder content in the composite ceramic target in S1 is 95 wt %.

[0011] Further defined, S1 was ground with acetone for 5-7 h.

[0012] It is further defined that the pre-sintering temperature in S1 is 700-900° C. and the time is 7-9 hours.

[0013] It is further defined that the pressing pressure in S1 is 30-40 MPa.

[0014] It is further defined that the secondary sintering temperature in S1 is 900-1100° C. and the time is 3-5 h.

[0015] It is further defined that the magnetron sputtering parameters in S2 are: argon flow rate 20-30 sccm, working gas pressure 0.3-1 Pa, sample stage rotation speed 5-20 rpm, target substrate distance 70-80 mm, power 150-180 W, and time 20-35 min.

[0016] It is further defined that the annealing temperature in S2 is 500-700° C. and the time is 0.5-1.5 h.

[0017] The second object of the present invention is to provide a Fe-doped GZO transparent conductive film prepared by the above method, wherein the film thickness is 200-300nm and the resistivity is less than 1.7×10 -3 Ω·cm, transmittance in the visible light range is >85%.

[0018] A third object of the present invention is to provide an application of the Fe-doped GZO transparent conductive film prepared by the above method in energy-saving glass and optoelectronic devices.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] The present invention adopts iron-gallium doped zinc oxide as target material, utilizes radio frequency magnetron sputtering in argon atmosphere, and co-dopes zinc oxide with different concentrations of iron and gallium to prepare zinc oxide transparent conductive film with low resistivity, high transmittance and wide band gap. The resistivity of the prepared zinc oxide transparent conductive film is better than 1.7×10 -3Ω·cm, the light transmittance in the visible light range is >85%. It can be applied to transparent conductive films such as energy-saving glass and optoelectronic devices, which is beneficial to improving conductivity and optical transmittance and reducing production costs. Description of the Drawings

[0021] Figure 1 SEM of the Fe-doped GZO film prepared in Example 1;

[0022] Figure 2 Light transmittance of the Fe-doped GZO film prepared in Example 1. Detailed Description of the Invention

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] The experimental methods used in the following embodiments are all conventional methods unless otherwise specified. The materials, reagents, methods and instruments used, unless otherwise specified, are all conventional materials, reagents, methods and instruments in this field, and those skilled in the art can obtain them through commercial channels.

[0025] The terms "comprising", "including", "having", "containing" or any other variation thereof used in the following embodiments are intended to cover non-exclusive inclusion. For example, a composition, step, method, article or device containing the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article or device.

[0026] When an equivalent, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, this should be understood to specifically disclose all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is separately disclosed. For example, when the range "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values and all integers and fractions within the range. In the specification and claims of this application, range limitations may be combined and / or interchanged, and if not otherwise stated, these ranges include all sub-ranges contained therein.

[0027] Example 1. The preparation method of the Fe-doped GZO transparent conductive film in this example includes the following steps:

[0028] (1) Target preparation

[0029] Mix Fe2O3 powder (mass fraction 1 wt%, purity 99.99%), Ga2O3 powder (mass fraction 4 wt%, purity 99.99%), and ZnO powder (mass fraction 95 wt%, purity 99.99%) in a mortar, grind them with acetone for 6 h, and sinter them in a sintering furnace at 800 °C for 8 h. Again, press the ground powder into a disk with a diameter of 1.5 cm under 35 MPa and sinter it at 1000 °C for 4 h.

[0030] (2) Substrate cleaning

[0031] First, place the glass substrate successively into acetone, deionized water, soapy water (concentration 20%), and deionized water, and clean it for 15 min, 10 min, 15 min, and 10 min respectively, then dry it with nitrogen (purity 99.99%) to obtain a clean glass substrate.

[0032] (3) Obtain Fe-doped GZO transparent conductive film by magnetron sputtering

[0033] Place the glass substrate prepared in step (2) on the sample stage of the PVD coating equipment, with the target-substrate distance of 75 mm, pump the background vacuum to 3×10 -4 Pa, then introduce Ar gas with a flow rate of 30 sccm, and use the ion source to clean the glass substrate. During coating, the Ar gas flow rate is 30 sccm, the working pressure is 0.7 Pa, the rotation speed of the sample stage is 5 r / min, the target is sputtered with a radio frequency power of 150 W for 30 min, and the film thickness is 280 nm.

[0034] (4) Annealing treatment

[0035] Under nitrogen atmosphere, the annealing temperature is 600 °C and the annealing time is 1 h.

[0036] Example 2: The preparation method of the Fe-doped GZO transparent conductive film in this example includes the following steps:

[0037] (1) Target preparation

[0038] Mix Fe2O3 powder (mass fraction 2 wt%, purity 99.99%), Ga2O3 powder (mass fraction 3 wt%, purity 99.99%), and ZnO powder (mass fraction 95 wt%, purity 99.99%) in a mortar, grind them with acetone for 6 h, and sinter them in a sintering furnace at 800 °C for 8 h. Again, press the ground powder into a disk with a diameter of 1.5 cm under 35 MPa and sinter it at 1000 °C for 4 h.

[0039] (2) Substrate cleaning

[0040] First, place the glass substrate successively into acetone, deionized water, soapy water (concentration 20%), and deionized water, and clean it for 15 min, 10 min, 15 min, and 10 min respectively, then dry it with nitrogen (purity 99.99%) to obtain a clean glass substrate.

[0041] (3) Obtain the Fe-doped GZO transparent conductive film by magnetron sputtering

[0042] Place the glass substrate prepared in step (2) on the sample stage of the PVD coating equipment, with the target-substrate distance of 75 mm, pump the base vacuum to 3×10 -4 Pa, then introduce Ar gas with a flow rate of 30 sccm, and use the ion source to clean the glass substrate. During coating, the Ar gas flow rate is 30 sccm, the working pressure is 0.7 Pa, the rotation speed of the sample stage is 5 r / min, the target is sputtered with a radio frequency power of 150 W for 30 min, and the film thickness is 280 nm.

[0043] (4) Annealing treatment

[0044] Under a nitrogen atmosphere, the annealing temperature is 600 °C and the annealing time is 1 h.

[0045] Example 3: The preparation method of the Fe-doped GZO transparent conductive film in this example includes the following steps:

[0046] (1) Target preparation

[0047] Mix Fe2O3 powder (mass fraction 4 wt%, purity 99.99%), Ga2O3 powder (mass fraction 1 wt%, purity 99.99%), and ZnO powder (mass fraction 95 wt%, purity 99.99%), grind them with acetone in a mortar for 6 h, and sinter them in a sintering furnace at 800 °C for 8 h. Again, press the ground powder into a disc with a diameter of 1.5 cm under 35 MPa, and sinter it at 1000 °C for 4 h.

[0048] (2) Substrate cleaning

[0049] First, place the glass substrate successively into acetone, deionized water, soapy water (concentration 20%), and deionized water, and clean it for 15 min, 10 min, 15 min, and 10 min respectively, then dry it with nitrogen (purity 99.99%) to obtain a clean glass substrate.

[0050] (3) Obtain the Fe-doped GZO transparent conductive film by magnetron sputtering

[0051] Place the glass substrate prepared in step (2) on the sample stage of the PVD coating equipment, with the target-substrate distance of 75 mm, pump the base vacuum to 3×10 -4First, the glass substrate was cleaned using an ion source with an Ar gas flow rate of 30 sccm after pumping down to a pressure of Pa. During film deposition, the Ar gas flow rate was 30 sccm, the working pressure was 0.7 Pa, the rotation speed of the sample stage was 5 r / min, and the target was sputtered with a radio frequency power of 150 W for 30 min, resulting in a film thickness of 280 nm.

[0052] (4) Annealing treatment

[0053] Under a nitrogen atmosphere, the annealing temperature was 600 °C and the annealing time was 1 h.

[0054] Comparative example: The preparation method of the ZnO transparent conductive film in this comparative example includes the following steps:

[0055] (1) Substrate cleaning

[0056] First, the glass substrate was successively placed in acetone, deionized water, soapy water (concentration 20%), and deionized water, and cleaned for 15 min, 10 min, 15 min, and 10 min respectively, and then dried with nitrogen (purity 99.99%) to obtain a clean glass substrate.

[0057] (2) Magnetron sputtering to obtain a ZnO transparent conductive film

[0058] The glass substrate prepared in step (1) was placed on the sample stage of the PVD coating equipment with a ZnO target substrate distance of 75 mm. The background vacuum was pumped down to 2×10 -4 Pa, then an Ar gas flow rate of 30 sccm was introduced, and the glass substrate was cleaned using an ion source. During film deposition, the Ar gas flow rate was 30 sccm, the working pressure was 0.7 Pa, the rotation speed of the sample stage was 5 r / min, and the ZnO target was sputtered with a radio frequency power of 120 W for 30 min, resulting in a film thickness of 263 nm.

[0059] (3) Annealing treatment

[0060] Under a nitrogen atmosphere, the annealing temperature was 600 °C and the annealing time was 1 h.

[0061] The performance results of the doped transparent conductive films obtained in Examples 1 - 3 and the undoped ZnO transparent conductive film obtained in the comparative example are shown in Table 1.

[0062] Table 1 Optical and electrical performance characteristics of the ZnO transparent conductive films in Examples 1 - 3 and the comparative example

[0063]

[0064] The above are only the preferred specific embodiments of the present invention. These specific embodiments are all different implementation manners based on the overall concept of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A preparation method of Fe-doped GZO transparent conductive film, characterized in that, The method: S1: Grind the Fe2O3 powder, Ga2O3 powder and ZnO powder with acetone, first perform pre-sintering, then grind and press again, and then perform secondary sintering to prepare a composite ceramic target; S2: Use the composite ceramic target as the sputtering target, deposit on the substrate surface by magnetron sputtering, and perform annealing treatment in a nitrogen atmosphere after deposition to obtain an Fe-doped GZO transparent conductive film.

2. The method according to claim 1, wherein In the composite ceramic target in S1, the content of Fe2O3 powder is 1-4wt%, the content of Ga2O3 powder is 1-4wt%, and the balance is ZnO powder.

3. The method according to claim 2, characterized in that, In the composite ceramic target in S1, the content of ZnO powder is 95wt%.

4. The method according to claim 1, wherein In S1, the pre-sintering temperature is 700-900°C and the time is 7-9h.

5. The method according to claim 1, characterized in that In S1, the pressing pressure is 30-40MPa, the secondary sintering temperature is 900-1100°C, and the time is 3-5h.

6. The method according to claim 1, wherein In S2, the magnetron sputtering parameters: argon gas flow rate 20-30 sccm, working gas pressure 0.3-1 Pa, sample stage rotation speed 5-20 rpm, target-substrate distance 70-80 mm, power 150-180 W, time 20-35 min.

7. The method according to claim 1, characterized in that In S2, the annealing temperature is 500-700°C and the time is 0.5-1.5h.

8. An Fe-doped GZO transparent conductive film prepared by the method according to any one of claims 1-7.

9. The thin film according to claim 8, characterized in that, The thickness of the thin film is 200 - 300 nm, and the resistivity is < 1.7×10 -3 Ω·cm, and the light transmittance in the visible light range is > 85%.

10. Application of the Fe-doped GZO transparent conductive film prepared by the method according to any one of claims 1-7 in energy-saving glass and liquid crystal display screens.

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