KR20120060602A - Method for designing transparent conductive material and method for producing single crystal of antimony doped barium tin oxide - Google Patents

Abstract

PURPOSE: A designing method of transparent conductive material is provided to provide transparent conductive material using for a transparent electrode of an electronic device. CONSTITUTION: A designing method of transparent conductive material comprises: a step of determining A_aB_bO_c, which has the conduction band gap of 1-5 eV, has plasma frequency of conduction electron which is lower than the minimum energy of visible light area, and has optical band gap energy higher than the maximum energy of visible light region, by calculation of energy band; and a step of determining A_aB_(b-x)C_xO_c of which optical band gap energy and conduction band gap is within the range of 80-100% from the optical band gap energy of the A_aB_bO_c, and the 70-100% from the conduction band gap, respectively, and of which Fermi energy is within the conduction band.

Description

Method for designing transparent conductive material and method for producing single crystal of antimony doped barium tin oxide}

The present invention relates to a method of designing a transparent conductive material that can be used as a transparent electrode of an electronic device, and to a method of manufacturing an antimony-doped barium tin oxide single crystal, which is one of the designed transparent conductive materials.

Indium tin oxide (ITO) in which tin is doped with indium oxide (In ₂ O ₃ ), which is a transparent conductive material, is used as a transparent electrode of electronic devices such as flat panel displays, solar cells, and transparent electronic devices. It is used. However, the use of ITO as an electrode due to the depletion of indium (In) has the disadvantage of increasing the cost. Thus, there is an increasing demand for transparent conductive materials that do not contain indium (In).

Although transparent conductive materials have been reported in impurity implanted binary oxides such as ZnO, SnO ₂ , TiO ₂ , CdO, Ga ₂ O ₃ and ternary oxides such as Cd ₂ SnO ₄ , these materials do not exceed the electrical conductivity of ITO. I can't. Therefore, there is a continuous need for securing a transparent conductive material having excellent electrical conductivity.

One object of the present invention is to provide a method of designing a transparent conductive material that can be used as a transparent electrode of an electronic device.

Another object of the present invention is to provide a method for producing antimony-doped barium tin oxide single crystal, which is one of the designed transparent conductive materials.

Disclosed is a method of designing a transparent conductive material in accordance with one aspect of the present invention. The method of designing the transparent conductive material may include optical band gap energy above the maximum energy in the visible region and plasma frequency of conduction electrons below the minimum energy in the visible region by energy band calculation. A _a B _b O _c having a plasma frequency and having a band width of 1 eV or more and less than 5 eV in the calculation of the conduction band (A and B are metal elements, respectively, and a, b, and c are 0≤a≤10, 0≤b≤10, and 0 <c≤10, and a and b are nonzero rational numbers at the same time). When A _a B _b O _c is determined, the optical bandgap energy and the band width of the conduction band are determined by the energy band calculation from the optical bandgap energy obtained by the band calculation of A _a B _b O _c and the band width of the conduction band, respectively. In the range of 100%, 70-100%, Fermi energy (Fermi energy) is located in the conduction band, the energy corresponding to the plasma frequency by the conduction electrons is more than 0.1eV and less than 1.8eV A _a B _bx C _x O _c (0 <x <1) is determined.

According to another aspect of the present invention, a method for preparing a single crystal of BaSn _{1 - X} Sb _X O ₃ is disclosed. The method for producing a single crystal of BaSn _{1 - X} Sb _X O ₃ forms a mixture by mixing a source material of Ba, a source material of Sn, a source material of Sb and a flux material. The mixture was heated up at a rate of 100-300 ° C./hr to form a single crystal of BaSn _{1 - X} Sb _X O ₃ , fixed at a temperature of 600-1300 ° C. for 6-24 hours, and then at 0.5-3 ° C./hr. The temperature is lowered to 600-1000 ° C. at a rate, and then cooled to room temperature at a rate of 100-300 ° C./hr. The single crystals of BaSn _{1 - X} Sb _X O ₃ are separated by acid treatment to remove the flux.

The source material of Ba comprises BaCO ₃ powder, and the source material of Sn is SnO ₂ Powder, wherein the source material of Sb is Sn ₂ O ₃ Powder, and the flux may include Cu ₂ O, KF or PbF ₂ powder. The source material and the flux material may be mixed such that the mole ratio of Ba: Sn: Sb: flux is 1: 1-x: x: y (0 <x ≦ 0.2, 3 <y ≦ 12).

When the flux material is Cu ₂ O, the temperature fixed for the 6-24 hours has a range of 1200-1300 ° C., and the target of temperature lowered at the rate of 0.5-3 ° C./hr is in the range of 900-1000 ° C. It can have When the flux material is KF, the temperature fixed for 6-24 hours has a range of 900-1160 ° C., and the target of temperature lowered at the rate of 0.5-3 ° C./hr has a range of 600-750 ° C. Can be. When the flux material is PbF ₂ , the temperature at which the flux is fixed for 6-24 hours is in the range of 1100-1200 ° C., and the target of the temperature lowered at the rate of 0.5-3 ° C./hr is in the range of 700-900 ° C. Can have

Nitric acid can be used in the acid treatment to remove the flux material to separate the single crystals of BaSn _{1 - X} Sb _X O ₃ .

In the design of transparent conductive materials, the theoretical methodology suggests that when the energy band calculation results have properties similar to those of ITO, they can be new transparent conductive materials.

Methods of making single crystals of the designed transparent conductive material can be presented to suggest possible properties of the transparent conductive material.

FIG. 1A is a graph showing a result of calculating an energy band of In ₂ O ₃ , and FIG. 1B is a graph showing a result of calculating an energy band of ITO doped with Sn of 6.5% in In ₂ O ₃ .
Figure 2a is a graph showing the results of the calculation of the energy band of BaSnO ₃ , Figure 2b is a graph showing the calculation results of the energy band of BaSn _0.875 Sb _0.125 O ₃ doped BaSnO ₃ 12.5% Sb.
3 is a lattice constant of BaSn _1-X Sb _X O ₃ according to the concentration of Sb obtained by calculation.
4 is a lattice constant of BaSn _1-X Sb _X O ₃ prepared according to the concentration of Sb.
5 is a flowchart for explaining a method for producing a single crystal of BaSn _1-X Sb _X O ₃ using the flux method.
6 is a heating cooling curve of the mixture for the preparation of single crystals of BaSn _1-X Sb _X O ₃ .
Figures 7a and 7b is a BaSn _{0 .95} Sb _{0 .05} O ₃ produced according to each Example Photomicrographs and polarization micrographs of single crystals are shown.
FIG. 8 is a graph of an XRD measurement in powder form of a BaSn _0.95 Sb _0.05 O ₃ single crystal sample prepared according to an embodiment.
9 is a graph showing the specific resistance of BaSn _0.95 Sb _0.05 O ₃ single crystal sample compared with the specific resistance of BaSn _1-x Sb _x O ₃ polycrystal sample.
10 is a graph showing the change in specific resistance of BaSn _0.95 Sb _0.05 O ₃ single crystal sample in comparison with the results of BaSn _1-x Sb _x O ₃ (x = 0.04, 0.1, 0.15) polycrystalline sample.
11 is BaSn _{0 .95} Sb _{0 .05} O ₃ It is a graph which computed the transmittance | permeability of the thin film computed from the absorption coefficient (alpha) obtained by the permeation experiment of the single crystal sample, and the said absorption coefficient (alpha).

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the present invention to those skilled in the art.

The visible light region has a wavelength range of about 400-700 nm and an energy range of 1.8-3.1 eV. The transparent conductive material is a material having electrical conductivity while transmitting light in the visible light region. The transparent conductive material may be formed by injecting a dopant into an insulator having an optical band gap energy of 3.1 eV or more that is transparent to the visible region. By injecting impurities, conductive electrons may be injected into the conduction band to have electrical conductivity.

In order to maintain the transmittance in the visible region even after the implantation of the impurity, the plasma frequency of the conduction electrons must be below the minimum energy of 1.8 eV in the visible region without significantly reducing the optical bandgap energy due to the implantation of the impurity. do.

In addition, in order to obtain high electrical conductivity, a band width (bandwidth: the difference between the lowest energy and the highest energy for one band) of the conduction band composed of ns orbitals (n is an integer) of a metal element is large. It is important to find a substance. Larger bands of conduction bands reduce the effective mass of the conduction electrons, thereby increasing electron mobility, resulting in higher electrical conductivity at the same concentration of conduction electrons.

Indium tin oxide (ITO), doped with tin (Sn) in a typical transparent conductive material, indium oxide (In ₂ O ₃ ) has an optical bandgap energy of about 3.7 eV similar to that of indium oxide (In ₂ O ₃ ) It has a high electrical conductivity of about 10 ⁴ S / cm.

A method for predicting the high electrical conductivity of indium tin oxide (ITO) from the energy band calculation results is presented below.

FIG. 1A is a graph showing a result of calculating an energy band of In ₂ O ₃ , and FIG. 1B is a graph showing a result of calculating an energy band of ITO doped with Sn of 6.5% in In ₂ O ₃ . (Source ON Mryasov and AJ Freeman, Physi Rev B 64, 233111 (2001))

In the graph of FIG. 1A, the band width W of the conduction band represented by the circle closest to the valence band is represented by about 2 eV. Of conduction band energy (and k is the momentum, m * is the effective ^{mass) E = m * v 2/} 2, k = m * v from ^{E = k 2 / (2m *} ) it can be written as. Since the conduction band of the graph of FIG. 1A has the form of a parabola, the slope of the parabola is proportional to 1 / (2m *) from E = k ² / 2m *. Therefore, the deeper the band width of the conduction band, the greater the inclination of the parabola, the smaller the effective mass m * of electrons. When the effective mass m * of electrons is small, the mobility of electrons becomes large. (Mobility, equation: μ = eτ / m *, e: charge of electron, τ: relaxation time)

The conduction band of the graph of FIG. 1A is formed from a 5s orbital of indium (In), and the conduction band is expected to have a large mobility when conduction electrons occur when the conduction band has a deep bandwidth of about 2 eV and a large parabolic slope. It is therefore expected to have high electrical conductivity due to large electron mobility. This shows that the electrical conductivity of the transparent conductive material can be predicted through the energy band calculation. However, the bandgap of the energy band calculation results is different from the optical bandgap actually measured. This difference comes from the fact that the calculation itself takes into account the factors calculated smaller than the actual bandgap and the absorption matrix element, so that the optical bandgap can be known, which means that the actual optical bandgap prediction of the material is difficult. It does not undermine the overall concept of predicting electrical conductivity from the calculation of energy bands.

In the graph of FIG. 1B, Fermi energy is present in the conduction band by doping Sn to In ₂ O ₃ . Therefore, the conduction electrons are filled in the conduction band, thereby increasing the electrical conductivity. On the other hand, the band width (W) of the conduction band represented by the circle closest to the valence band in the graph of FIG. 1B is smaller than that of FIG. 1A but appears to be about 2 eV. Since the dispersion of the conduction band of ITO is narrow, similar to the dispersion of the conduction band of In ₂ O ₃ , it can be predicted that the effective mass of the electron becomes smaller, resulting in higher electron mobility and consequently higher electrical conductivity.

The method of predicting the high electrical conductivity of ITO from the energy band calculation results as described above can be applied to design new transparent conductive materials. Hereinafter, a method of designing a new transparent conductive material will be described.

First, A _a B _b O _c by energy band calculation (A, B are metal elements, respectively, a, b, c are 0≤a≤10, 0≤b≤10, 0 <c≤10, and a and b are non-zero rational numbers) do. In this case, in order for A _a B _b O _c to be transparent to visible light, the optical bandgap energy must have a maximum energy of the visible light region or more, and the plasma frequency of the conduction electrons must have a frequency less than the minimum energy of the visible light region. In addition, the A _a B _b O _c in order to have a good electrical conductivity after doping of the other elements, the band width of the conduction band on the A _a B _b O _c band calculated to be at least 1eV. The upper limit of the calculation of the bandwidth of the conduction band may be 5 eV. This conduction band can be formed from the outermost s orbitals of element A or element B. In this case, the calculated energy gap of the material may be 1 eV or more, but the actual optical band gap energy may be 3.1 eV or more. On the other hand, the optical bandgap energy may be less than 7eV.

When A _a B _b O _c is determined, the optical bandgap energy and the band width of the conduction band are determined by the energy band calculation from the optical bandgap energy obtained by the band calculation of A _a B _b O _c and the band width of the conduction band, respectively. In the range of 100%, 70-100%, Fermi energy (Fermi energy) is located in the conduction band, the energy corresponding to the plasma frequency by the conduction electrons is more than 0.1eV and less than 1.8eV A _a B _{b - x} C _x O _c Determine (0 <x <1). The above conditions are conditions for A _a B _{b - x} C _x O _c formed by doping A _a B _b O _c to impart electrical conductivity while showing excellent electrical conductivity while maintaining transparency.

Hereinafter will be described the process for predicting the transparency and electrical conductivity properties from an energy band of barium tin oxide (BaSnO ₃₎ Antimony (Sb) is doped barium tin antimony oxide (Sb BaSn _{0 .875 0 .125} O _3).

Figure 2a is a graph showing a calculation result of the energy band of BaSnO _3, Fig. 2b is a graph showing the calculation result of the 12.5% of Sb doped BaSn _{0 .875} Sb _{0 .125} O ₃ energy band to BaSnO _3.

BaSnO ₃ has an optical bandgap energy of 3.1 eV and similar to In ₂ O ₃ in that the band width (W) of the conduction band made of 5s orbital of antimony (Sb) is about 2 eV as shown in FIG. Do. By optical bandgap energy of 3.1 eV, BaSnO ₃ is transparent to the visible region. When Sb ^{5 +} is introduced into the Sn ^{4 +} site of BaSnO ₃ , five electrons are provided, and the result of calculating the energy band structure at this time is shown in the graph of FIG. 2B.

If Figures 2a and FIG 2b, the dispersion of the conduction band of BaSnO ₃ Antimony (Sb) is doped BaSn _{0 .875} Sb _{0 .125} O _3, antimony (Sb) from a larger distribution of the conduction band of the undoped BaSnO ₃ Does not change Thus, conduction electrons of BaSn _{0 .875} Sb _{0 .125} O ₃ are predicted to have a high mobility. In addition, it can be seen from the graph of FIG. 2B that Fermi energy is present on the conduction band that the conduction electrons are filled in the conduction band. That is, as in the case of ITO, BaSnO ₃ has a large bandwidth of conduction band dispersion before and after doping of tin (Sb) impurities, and conduction electrons are filled in the conduction band after doping of tin (Sb) impurities. BaSn _{0 .875} Sb _{0 .125} O ₃ impurities are doped can be predicted to have a high electrical conductivity.

On the other hand, antimony (Sb) can also exist in the form of Sb ^{3 +} in the lattice (lattice), so knowing exactly whether the introduced antimony (Sb) is actually present as Sb ^{3 +} or Sb ^{5 +} to determine the properties of the material It is important to anticipate. In the calculation results using the energy band, it was predicted that the lattice became larger when antimony (Sb) was present as Sb ^{5 +} . This prediction result is consistent with the phenomenon that the lattice becomes larger as doping (x) of antimony (Sb) increases in BaSn _{1 - x} Sb _x O ₃ doped with antimony (Sb).

3 is a lattice constant of BaSn _1-X Sb _X O ₃ according to the concentration of antimony (Sb) present as Sb ^{5 +} obtained by calculation. Lattice constant values were obtained by calculating using the VASP (LDA) program. In the graph of FIG. 3, the lattice constant of BaSn _1-X Sb _X O ₃ increased as the concentration of antimony (Sb) increased.

4 is a lattice constant of BaSn _{1 - X} Sb _X O ₃ prepared according to the concentration of Sb. The lattice constants of the graph of FIG. 4 were obtained from XRD spectra of BaSn _{1 - X} Sb _X O ₃ samples with varying concentrations of Sb. Although smaller than the increasing slope of the lattice constant of the graph of FIG. 3, the lattice constant of BaSn _{1 - X} Sb _X O _{3 also} increased as the concentration of antimony (Sb) increased in the graph of FIG. 4. This shows some agreement between the calculation results and the experimental results. Of antimony (Sb) doped to BaSnO ₃ From these results it can be seen that the present as Sb ^{+ 5.}

As discussed above, the transparent conductivity of ITO can be predicted from the optical bandgap energy of the ITO and the band width of the conduction band are deep and the Fermi energy is in the conduction band. In addition, in the design of a transparent conductive material, it can be predicted that the material can be a transparent conductive material when the calculated energy band of the material has a shape similar to that of the ITO. That is, in the design of the transparent conductive material, a promising transparent conductive material can be found by calculating the energy band and comparing it with the energy band of ITO.

BaSn _{1 - X} Sb _X O ₃ of the energy band is in analogy to the energy band of the ITO, a high band gap from having the energy and the Fermi energy is located in a deep band width and the conduction band of the conduction band BaSn _{1 -} the _X Sb _X O ₃ transparent It can be expected that the characteristics of conductivity are excellent.

Describes an Sb _{X X} O ₃ measured characteristics of _- the following method for producing a transparent conductive energy band calculation is predicted BaSn _{X 1 -X} Sb O characteristics of the _third and by BaSn _1.

FIG. 5 is a flowchart illustrating a method of preparing single crystal BaSn _{1 - X} Sb _X O ₃ using a flux method.

Referring to FIG. 5, first, a source material of Ba, a source material of Sn, a source material of Sb, and a flux material are mixed (S110). BaCO ₃ may be used as the source material of Ba, for example SnO ₂ may be used as the source material of Sn, and Sb ₂ O ₃ may be used as the source material of Sb. As flux material, for example Cu ₂ O, KF or PbF ₂ can be used which can dissolve the metal source materials in the liquid state. The metal source materials and the flux material may use powder form. The molar ratio of each metal in the mixture is Ba: Sn: Sb = 1: 1-x: x (0 <x ≦ 0.2) and the flux material is a molar ratio of 1: y relative to Ba. 5 <y≤12 for Cu ₂ O, 6 <y≤12 for KF, and 3 <y≤7 for PbF ₂ .

Subsequently, the mixture is heated and then cooled (S120). The platinum crucible containing the mixture is placed in a high temperature furnace, and the temperature of the high temperature furnace is raised and then slowly lowered. 6 is a heating cooling curve of the mixture. Referring to FIG. 6, the temperature is raised at a rate of A ° C./hr at room temperature, and the temperature is fixed at B ° C. for C hours. Thereafter, the temperature is slowly lowered to E ° C at a rate of D ° C./hr, and then lowered to room temperature at a high rate of F ° C./hr. The source material of the metal is dissolved in the flux material by heating, and then BaSn _{1 - X} Sb _X O ₃ single crystal is formed in the flux material by cooling.

When Cu ₂ O is used as the flux, A may be 100-300, B may be 1200-1300, C may be 6-24, D may be 0.5-3, E may be 900-1000, and F may be 100-300. When using KF as a flux, A may be 100-300, B may be 900-1160, C may be 6-24, D may be 0.5-3, E may be 600-750, and F may be 100-300. When using PbF ₂ as flux, A may be 100-300, B may be 1100-1200, C may be 6-24, D may be 0.5-3, E may be 700-900, and F may be 100-300.

After removing the platinum crucible from the high temperature furnace, a solid flux material is dissolved with an acid to separate BaSn _{1 - X} Sb _X O ₃ single crystal (S130). The acid may use nitric acid, for example.

Example

Powders of BaCO ₃ : SnO ₂ : Sb ₂ O ₃ : Cu ₂ O were mixed evenly in a mole ratio of 1: 0.95: 0.025: 6. The mixed powder was placed in a platinum crucible, heated in a high temperature furnace, and cooled. The temperature was raised at a rate of 200 ° C./h at room temperature and heated at 1350 ° C. for 8 hours, the temperature was reduced to 950 ° C. at a rate of 1 ° C./h, and the temperature was reduced to room temperature at a rate of 100-300 ° C./h. Taking the Cu ₂ O is dissolved in the nitric acid solution was taken out over a platinum crucible at a high temperature BaSn _{0 .95} Sb _{0 .05} O ₃ Single crystals were separated.

The BaSn _{0 .95} Sb _{0 .05} O ₃ Optical micrographs of the single crystals were obtained, and X-ray diffraction (XRD), electrical conductivity, and transmittance were measured.

Optical micrograph

Figures 7a and 7b is a BaSn _{0 .95} Sb _{0 .05} O ₃ produced according to each Example Photographs of optical and polarized light microscopes of single crystals. From the photographs of FIGS. 7A and 7B, it can be seen that BaSn _0.95 Sb _0.05 O ₃ single crystal has a diameter of about 1 mm and a thickness of 0.5-1 mm and has a deep blue color or indigo blue color.

XRD (X- ray Diffraction )

8 is carried out at a BaSn _{0 .95} Sb _{0 .05} O ₃ prepared by Example XRD measurement graph in powder form for a single crystal sample. BaSn _{0 .95} from the graph of Figure 8 Sb _{0 .05} O ₃ It can be seen that the XRD peak of the single crystal sample coincides with the XRD peak of BaSnO ₃ , from which it can be seen that the BaSn _0.95 Sb _0.05 O ₃ single crystal sample was grown in a single phase without structurally other material phases.

Electrical conductivity

9 is BaSn_{0 .95}Sb_{0 .05}O₃ The resistivity of the single crystal sample (x = 0.05) is determined by BaSn._{One -x}Sb_xO₃It is a graph compared with the specific resistance of a polycrystal sample. BaSn_{One - x}Sb_xO₃ The composition ratio x of Sb of a polycrystal sample is 0.04, 0.1, and 0.15. BaSn in the graph of FIG._{0 .95}Sb_{0 .05}O₃ Single crystal The specific resistance of the sample is BaSn_{One - x}Sb_xO₃ (x = 0.04, 0.1, 0.15) 100 times lower than the resistivity of the polycrystalline sample. BaSn_{0 .95}Sb_{0 .05}O₃ Single crystal The specific resistance of the sample was 0.44 mΩ-cm at room temperature, and the electrical conductivity was 2260 S / cm.

10 is BaSn _{0 .95} Sb _{0 .05} O ₃ It is a graph showing the change of the specific resistance according to the temperature of the single crystal sample compared with the result of BaSn _{1- x} Sb _x O ₃ (x = 0.04, 0.1, 0.15) polycrystalline sample. The resistivity of each sample is expressed as a percentage of its resistivity at 300K. And FIG polycrystalline samples from the graph 10, like BaSn _{0 .95} Sb _{0 .05} O ₃ It can be seen that the variation of the specific resistance with temperature of the single crystal sample is not large from room temperature to a low temperature of 10K. On the other _{hand, BaSn 0 .95 Sb 0 .05 O} 3 polycrystalline samples prepared It can be seen that the specific resistance of the single crystal sample is remarkably low, because scattering due to grain boundary in the BaSn _1-x Sb _x O ₃ polycrystal sample acts to increase the specific resistance.

9 and 10 are results obtained from bulk samples but BaSn _{1 -x} Sb _x O ₃ Even when applied as a thin film, it is expected that excellent electrical conductivity can be obtained from a single crystal rather than a polycrystal.

Permeability

11 is BaSn _{0 .95} Sb _{0 .05} O ₃ It is a graph which calculated the absorption coefficient (alpha) with respect to the light energy of the visible light region obtained by the transmission experiment of the single crystal sample, and the transmittance | permeability with respect to the thin film computed from the said absorption coefficient. An absorption coefficient was obtained using a 29 μm thick BaSn _0.95 Sb _0.05 O ₃ single crystal sample, and the permeability was calculated for the 120 nm and 3 μm thick thin films. From the graph of FIG. 11, it is possible to predict 80% transmittance in the 120 nm single crystal thin film and 70% transmittance in the 3 μm single crystal thin film. The transmittance of 70% to 80% shows that BaSn _0.95 Sb _0.05 O ₃ can be sufficiently used as a transparent electrode of the electronic device.

The electrical and optical properties of an exemplary single crystal prepared by examples BaSn _{0 .95} Sb _{0 .05} O ₃ informs the range of possible characteristics BaSn _{0 .95} Sb _{0 .05} O _3, if a thin film is used as transparent electrodes of electronic devices.

Claims (20)

The band of conduction bands has an optical band gap energy above the maximum energy in the visible region and a plasma frequency of conduction electrons below the minimum energy in the visible region by energy band calculation. A _a B _b O _c greater than or equal to 1 eV and less than 5 eV Determining (A, B are metal elements, respectively, a, b, c are 0 ≦ a ≦ 10, 0 ≦ b ≦ 10, 0 <c ≦ 10, and a and b are non-zero rational numbers at the same time); And
The optical bandgap energy and the band width of the conduction band by the energy band calculation are in the range of 80-100% and 70-100% from the optical bandgap energy obtained in the band calculation of A _a B _b O _c and the band width of the conduction band, respectively. Fermi energy (Fermi energy) is located in the conduction band, the energy corresponding to the plasma frequency by the conduction electrons is at least 0.1 eV and less than 1.8 eV A _a B _{b - x} C _x O _c Determining (0 <x <1); and a method of designing a transparent conductive material. The method of claim 1, wherein the conduction band is formed from an outermost s orbital of the A element or the B element. The method of claim 1, wherein the element B comprises tin (Sn). The method of claim 1, wherein the element A comprises a Group 2 metal. The method of claim 1, wherein the optical bandgap energy is at least 3.1 eV and less than 7 eV. The method of claim 1, wherein the plasma frequency is greater than 0.1 eV and less than 1.8 eV. 2. The method of claim 1, wherein according to said X value A _a B _{b - x} C _x O _c of the change in the oxidation number of the element C in the lattice constant (lattice constant) of the actual crystal assumed by calculating A _a B _{b -} and comparing the change in lattice constant of _x C _x O _c to determine the ionized water of the C element. Mixing a source material of Ba, a source material of Sn, a source material of Sb and a flux material to form a mixture;
The mixture was heated up at a rate of 100-300 ° C./hr to form a single crystal of BaSn _{1 - X} Sb _X O ₃ , fixed at a temperature of 600-1300 ° C. for 6-24 hours, and then at 0.5-3 ° C./hr. Cooling down to room temperature at a rate of 100-300 ° C./hr, followed by a temperature down to 600-1000 ° C. at a rate;
The method of the Sb _{X X} O ₃ single _{crystal-BaSn 1} containing; _- the BaSn ₁ by acid treatment of the cooled output step of separating the single crystal _{X X} O ₃ Sb The method of claim 8, BaSn ₁ that the source material of the Ba comprises BaCO _{3 -} The method of the Sb _{X X} O ₃ single crystal. The method of claim 8, wherein the source material of Sn is SnO ₂ Method for producing a single crystal of BaSn _{1 - X} Sb _X O ₃ comprising a. The method of claim 8, wherein the source material of Sb is Sn ₂ O ₃ Method for producing a single crystal of BaSn _{1 - X} Sb _X O ₃ comprising a. 9. The method of claim 8 wherein the flux is a method of producing a BaSn _{1 -X} Sb _X O ₃ single crystal containing Cu ₂ O, CuO, KF or PbF _2. The source material of Ba according to claim 12, wherein the molar ratio of Ba: Sn: Sb: flux is 1: 1-x: x: y (0 <x ≦ 0.2, 3 <y ≦ 12). A method for producing a single crystal of BaSn _{1 - X} Sb _X O ₃ to determine the mixing ratio of the material, the source material of the Sb and the flux material. The single crystal of BaSn _{1 - X} Sb _X O ₃ according to claim 13, wherein the mixing ratio is determined such that the molar ratio of Ba: Cu is 1: y (5 <y ≦ 12) when the flux material is Cu ₂ O. Manufacturing method. The method for producing a single crystal of BaSn _{1 - X} Sb _X O ₃ according to claim 13, wherein the mixing ratio is determined such that the molar ratio of Ba: K is 1: y (6 <y ≦ 12) when the flux material is KF. . 14. The preparation of single crystal of BaSn _{1 - X} Sb _X O ₃ according to claim 13, wherein when the flux material is PbF ₂ , the mixing ratio is determined such that the molar ratio of Ba: Pb is 1: y (3 <y ≦ 7). Way. The method of claim 12, wherein when the flux material is Cu ₂ O, the temperature fixed for 6-24 hours has a range of 1200-1300 ℃, the target of the temperature lowered at the rate of 0.5-3 ℃ / hr Method for producing a single crystal of BaSn _{1 - X} Sb _X O ₃ having a range of 900-1000 ℃. 13. The method of claim 12, wherein when the flux material is KF, the temperature fixed for 6-24 hours has a range of 900-1160 ° C, and the target of temperature lowered at the rate of 0.5-3 ° C / hr is 600-. Method for producing a single crystal of BaSn _{1 - X} Sb _X O ₃ having a range of 750 ℃. 13. The method of claim 12, wherein, in the case of PbF ₂ , the temperature at which the flux material is fixed for 6-24 hours has a range of 1100-1200 ° C., and the target of temperature lowered at the rate of 0.5-3 ° C./hr is 700. Method for producing a single crystal of BaSn _{1 - X} Sb _X O ₃ having a range of -900 ℃. The method for producing a single crystal of BaSn _{1 - X} Sb _X O ₃ according to claim 8, wherein nitric acid is used in the acid treatment.

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