JP2013065664A - Nano-heterostructure pn-junction element and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pn-junction element having a nanostructure and excellent in photoelectric conversion efficiency such as light-emitting efficiency.SOLUTION: The nano-heterostructure pn-junction element comprises: a nano-heterostructure body, having a three-dimensional periodic structure in which an average value of a unit length of the repeated structure is 1 to 100nm, and in a matrix composed of one inorganic component out of a p-type semiconductor material and an n-type semiconductor material, the other inorganic component, out of the p-type semiconductor material and the n-type semiconductor material, having a shape selected from a group composed of a columnar shape, a gyroid shaped, and a layer shape, is arranged three-dimensionally and periodically; a p-type semiconductor material; and an n-type semiconductor material. The nano heterostructure body is sandwiched between the p-type semiconductor layer and the n-type semiconductor layer so that an end part of a pn junction surface formed with the p-type semiconductor material and the n-type semiconductor material in the nano-heterostructure body is brought in contact with at least one of surfaces of semiconductor layers out of the p-type semiconductor layer and the n-type semiconductor layer.

Description

  The present invention relates to a pn junction element having a nanoheterostructure and a method for manufacturing the same.

  A pn junction element formed by joining a p-type semiconductor material and an n-type semiconductor material has a property of conducting electricity only in one direction (rectification action), converts electrical energy into light energy, It has the property of converting into electric energy (photoelectric conversion action) and is used in various electronic devices such as diodes, light emitting elements, and solar cells.

  For example, Japanese Unexamined Patent Application Publication No. 2007-294972 (Patent Document 1) discloses a light emitting element including a semiconductor light emitting structure having a pn junction structure on a substrate having a nanostructure. In this light emitting device, when a photon generated in a semiconductor light emitting structure is emitted to the outside of the light emitting device by applying a voltage, the photon that has traveled to the substrate is refracted or scattered by the nanostructure formed on the surface of the substrate. Thus, the amount of photons emitted to the outside of the light emitting element is increased to improve the light emission characteristics of the light emitting element.

JP 2007-294972 A

  However, since the pn junction structure of the semiconductor light emitting structure constituting the light emitting element described in Patent Document 1 is a single junction in which a p-type semiconductor layer and an n-type semiconductor layer are stacked, the pn junction area is small, and the semiconductor light emission The luminous efficiency of the structure itself is not always sufficient.

  The present invention has been made in view of the above-described problems of the prior art, and has an object to provide a pn junction element having a nanostructure and excellent photoelectric conversion efficiency such as light emission efficiency and a method for manufacturing the same. .

  As a result of intensive studies to achieve the above object, the present inventors have found that the first polymer block component constituting the block copolymer and one inorganic precursor of the p-type semiconductor material precursor and the n-type semiconductor material precursor. And the second polymer block component and the other inorganic precursor of the p-type semiconductor material precursor and the n-type semiconductor material precursor, respectively, in combination, thereby utilizing the self-organization of the block copolymer to An inorganic of one of the p-type semiconductor material and the n-type semiconductor material is formed by forming a phase separation structure and converting the inorganic precursor to a p-type semiconductor material and an n-type semiconductor material, respectively, and removing the block copolymer. The other inorganic component is arranged in a matrix of components in a predetermined shape with a three-dimensional nanoscale periodicity. A nanoheterostructure having a pn junction surface formed by the p-type semiconductor material and the n-type semiconductor material is obtained, and the pn junction is sandwiched between the p-type semiconductor layer and the n-type semiconductor layer The present inventors have found that the device is excellent in photoelectric conversion efficiency such as luminous efficiency, and have completed the present invention.

That is, the manufacturing method of the nanoheterostructure pn junction element of the present invention is as follows.
A block copolymer formed by bonding at least a first polymer block component and a second polymer block component that are immiscible with each other; a first inorganic precursor that is one of a p-type semiconductor material precursor and an n-type semiconductor material precursor; A first step of preparing a raw material solution by dissolving a second inorganic precursor that is the other of the p-type semiconductor material precursor and the n-type semiconductor material precursor in a solvent;
At least a first polymer phase composed of the first polymer block component introduced with the first inorganic precursor; and a second polymer phase composed of the second polymer block component introduced with the second inorganic precursor; Phase-separation treatment for forming regularly arranged nanophase-separated structures by self-organization, and the p-type semiconductor material precursor and the n-type semiconductor material precursor as a p-type semiconductor material and an n-type semiconductor material, respectively. A conversion process for converting, and a removal process for removing the block copolymer from the nanophase-separated structure, wherein the p is contained in a matrix composed of one inorganic component of the p-type semiconductor material and the n-type semiconductor material. The other inorganic component of the n-type semiconductor material and the n-type semiconductor material is selected from the group consisting of a columnar shape, a gyroidal shape, and a layered shape In Jo, a second step of allowed to form on a nano-hetero structure are arranged three-dimensionally and periodically, p-type semiconductor layer and n-type semiconductor layer while the is first semiconductor layer of,
A second semiconductor layer which is the other of the p-type semiconductor layer and the n-type semiconductor layer is formed on the nanoheterostructure, and is formed by the p-type semiconductor material and the n-type semiconductor material in the nanoheterostructure. A third step of obtaining a nano-heterostructure pn junction element in which an end portion of the pn junction surface is in contact with the surface of at least one of the p-type semiconductor layer and the n-type semiconductor layer;
It is the method characterized by including.

  In the second step, a nanoheterostructure in which the shape of the inorganic component arranged three-dimensionally and periodically in the matrix is columnar or layered, and the pn junction surface in the nanoheterostructure is the first Preferably, the first semiconductor layer is formed on the first semiconductor layer so as to be perpendicular to the surface of the one semiconductor layer, and after the layer made of the raw material solution is formed on the first semiconductor layer, By performing the phase separation process while exposing the upper surface of the layer to be exposed to a vapor of a good solvent for at least one of the p-type semiconductor material precursor and the n-type semiconductor material precursor. More preferably, the bonding surface is formed in a direction perpendicular to the surface of the first semiconductor layer.

  In the third step, the pn junction surface in the nanoheterostructure is formed on the nanoheterostructure in which the shape of the inorganic component arranged three-dimensionally and periodically in the matrix is columnar or layered. Preferably, the second semiconductor layer is formed so that is perpendicular to the surface of the second semiconductor layer.

The difference in solubility parameter between the first inorganic precursor used in the present invention and the first polymer block component is preferably 2 (cal / cm ³ ) ^1/2 or less, and the second inorganic precursor and the first polymer block component The difference in solubility parameter from the two polymer block component is preferably 2 (cal / cm ³ ) ^1/2 or less.

  Further, the difference in solubility parameter between the first polymer block component and the first inorganic precursor used in the present invention is smaller than the difference in solubility parameter between the first polymer block component and the second inorganic precursor. Is preferred. The difference in solubility parameter between the second polymer block component and the second inorganic precursor is preferably smaller than the difference in solubility parameter between the second polymer block component and the first inorganic precursor.

The block copolymer used in the present invention comprises at least one first polymer block component selected from the group consisting of polystyrene component, polyisoprene component and polybutadiene component, polymethyl methacrylate component, polyethylene oxide component, polyvinyl pyridine component and poly When at least one second polymer block component selected from the group consisting of acrylic acid components is bonded,
The first inorganic precursor has at least one structure selected from the group consisting of a phenyl group, a long hydrocarbon chain having 5 or more carbon atoms, a cyclooctatetraene ring, a cyclopentadienyl ring, and an amino group. Provided is preferably at least one of an organometallic compound and an organometalloid compound,
The second inorganic precursor is at least one selected from the group consisting of metal or metalloid salts, metal or metalloid alkoxides having 1 to 4 carbon atoms, and metal or metalloid acetylacetonate complexes. Is preferred.

Further, the nano-heterostructure pn junction element of the present invention that can be obtained by the manufacturing method of the present invention has a matrix composed of one inorganic component of the p-type semiconductor material and the n-type semiconductor material. The other inorganic component of the p-type semiconductor material and the n-type semiconductor material is three-dimensionally and periodically arranged in a shape selected from the group consisting of a columnar shape, a gyroid shape, and a layer shape, and has a repeating structure Comprising a nano-heterostructure having a three-dimensional periodic structure having an average length of one unit of 1 nm to 100 nm, a p-type semiconductor layer, and an n-type semiconductor layer,
An end portion of a pn junction surface formed by the p-type semiconductor material and the n-type semiconductor material in the nanoheterostructure is at least one of the p-type semiconductor layer and the n-type semiconductor layer. The p-type semiconductor layer and the n-type semiconductor layer sandwich the nanoheterostructure so as to be in contact with the surface.

  In the nanoheterostructure pn junction element of the present invention, when the shape of the inorganic component three-dimensionally and periodically arranged in the matrix is a columnar or layered shape, the pn junction surface in the nanoheterostructure is the p-type. It is preferably formed in a direction perpendicular to the surface of at least one of the semiconductor layer and the n-type semiconductor layer.

  In the nanoheterostructure pn junction element of the present invention, the p-type semiconductor layer preferably contains a semiconductor material and an impurity element of the same type as the p-type semiconductor material in the nanoheterostructure, and the n-type semiconductor layer As for, what contains the same kind of semiconductor material and impurity as the n-type semiconductor material in the said nanoheterostructure is preferable.

  The reason why the nanoheterostructure pn junction element of the present invention can be obtained by the method of the present invention is not necessarily clear, but the present inventors infer as follows. That is, first, a block copolymer formed by bonding two types of polymer block components A and B that are immiscible with each other is a nano-structure in which the A phase and the B phase are spatially separated by heat treatment at a temperature equal to or higher than the glass transition point. Configure the phase separation structure (self-organization). At that time, the phase separation structure generally varies depending on the molecular weight ratio of the polymer block components. Specifically, when the molecular weight ratio of A: B is 1: 1, generally a layered layered structure is adopted, and as the molecular weight ratio deviates from 1: 1, a gyration in which two continuous phases are intertwined. It changes from a Lloyd structure to a columnar structure. FIG. 1 is a schematic diagram showing a nanophase-separated structure produced from a block copolymer, and shows a layered structure (a), a gyroidal structure (b), and a columnar structure (c) from the left. In general, the right side structure has a higher ratio of A.

In the method for producing a nano-heterostructure pn junction element of the present invention, first, a plurality of inorganic precursors are arranged three-dimensionally with nano-scale periodicity using the self-assembly of the block copolymer. That is, a block copolymer composed of a plurality of polymer block components that are immiscible with each other is phase-separated on a nanoscale by self-assembly as described above. In that case, in this invention, the 1st polymer block component which comprises a block copolymer, the 1st inorganic precursor which is one of a p-type semiconductor material precursor and an n-type semiconductor material precursor, and a 2nd polymer block component And a second inorganic precursor, which is the other of the p-type semiconductor material precursor and the n-type semiconductor material precursor, in combination, and the difference in solubility parameter from the first polymer block component is 2 ( cal / cm ³ ) ^1/2 or less and a second inorganic precursor having a solubility parameter difference of 2 (cal / cm ³ ) ^1/2 or less between the second polymer block component and Are preferably used in combination. As a result, the first inorganic precursor and the second inorganic precursor are sufficiently introduced into the first polymer block component and the second polymer block component, respectively, and form a nanophase separation structure together with the self-assembly of the block copolymer. The inorganic precursor is arranged with a nanoscale periodicity three-dimensionally by setting the nanophase separation structure to a predetermined structure.

Furthermore, in the present invention, by converting the p-type semiconductor material precursor and the n-type semiconductor material precursor to a p-type semiconductor material and an n-type semiconductor material, respectively, and removing the block copolymer, Nanohetero, in which the other inorganic component is arranged in a predetermined shape three-dimensionally with a specific nanoscale periodicity in a matrix composed of one of the p-type semiconductor material and the n-type semiconductor material according to the shape. A structure is obtained. In the present invention, the first inorganic precursor and the second inorganic precursor are used in combination with the first polymer block component and the second polymer block component, respectively, and further, the difference between these solubility parameters. Are preferably 2 (cal / cm ³ ) ^1/2 or less. As a result, the amount of each inorganic precursor introduced into each polymer block component is sufficiently increased, and therefore the p-type semiconductor material precursor and the n-type semiconductor material precursor are converted into a p-type semiconductor material and an n-type semiconductor material, respectively. The inventors infer that the nanoscale three-dimensional periodic structure is sufficiently maintained even if the block copolymer is removed.

The “solubility parameter” in the present invention is a so-called “SP value” defined by the regular solution theory introduced by Hildebrand, and has the following formula:
Solubility parameter δ [(cal / cm ³ ) ^1/2 ] = (ΔE / V) ^1/2
(In the formula, ΔE represents molar evaporation energy [cal], and V represents molar volume [cm ³ ].)
It is a value obtained based on.

  In addition, the “average length of one unit of the repeating structure” in the present invention is the average distance between centers of adjacent ones of the other inorganic components arranged in the matrix composed of one inorganic component. This value corresponds to the so-called periodic structure interval (d). The interval (d) of the periodic structure is obtained by small angle X-ray diffraction as follows. The columnar, gyroidal, or layered structure according to the present invention can also be defined by a characteristic diffraction pattern measured by small-angle X-ray diffraction as follows.

  That is, Bragg reflection from a characteristic lattice plane of a pseudo crystal lattice in which structures having a columnar shape, a gyroid shape, a layer shape, and the like are periodically arranged in a matrix is observed by small-angle X-ray diffraction. At that time, if a periodic structure is formed, a diffraction peak is observed, and a structure such as a columnar shape, a gyroidal shape, or a layered shape can be specified from the ratio of the magnitudes of these diffraction spectra (q = 2π / d). . Further, from the peak position of the diffraction peak, the interval (d) of the periodic structure can be obtained by Bragg's formula (nλ = 2dsin θ; λ indicates the X-ray wavelength and θ indicates the diffraction angle). Table 1 below shows the relationship between each structure and the ratio (q) of the diffraction spectrum size at the peak position. In addition, it is not necessary to confirm all the peaks as shown in Table 1, and it is sufficient that the structure can be identified from the observed peaks.

  In addition, it is possible to specify a columnar structure, a gyroidal structure, or a layered structure according to the present invention using a transmission electron microscope (TEM), and thereby the shape and periodicity can be determined and evaluated. Furthermore, it is also possible to discriminate the three-dimensionality in more detail by using observation from various directions and three-dimensional tomography.

  According to the present invention, a nanoheterostructure in which one inorganic component of a p-type semiconductor material and an n-type semiconductor material is arranged with a nanoscale periodicity in the other inorganic component is p-type. A pn junction element that is sandwiched between the semiconductor layer and the n-type semiconductor layer and has excellent photoelectric conversion characteristics such as light emission efficiency can be obtained.

It is a schematic diagram which shows the nano phase separation structure produced | generated from an AB type block copolymer. It is a schematic diagram which shows one suitable embodiment of the nanoheterostructure pn junction element of this invention. It is a schematic diagram which shows another suitable one embodiment of the nanoheterostructure pn junction element of this invention. It is a schematic diagram which shows another suitable one Embodiment of the nanoheterostructure pn junction element of this invention. It is a schematic diagram which shows one embodiment of the nanoheterostructure pn junction element of this invention provided with an electrode. It is a schematic diagram which shows another embodiment of the nanoheterostructure pn junction element of this invention provided with an electrode. 2 is a transmission electron micrograph of the nanoheterostructure obtained in Example 1. FIG. 2 is a transmission electron micrograph of the nanoheterostructure obtained in Example 2. FIG. It is a schematic diagram which shows the conventional single junction pn junction element.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

  First, the nanoheterostructure pn junction device of the present invention will be described. In the nano-heterostructure pn junction element of the present invention, the other inorganic component of the p-type semiconductor material and the n-type semiconductor material is in the matrix composed of one inorganic component of the p-type semiconductor material and the n-type semiconductor material. A shape selected from the group consisting of a columnar shape, a gyroid shape, and a layered shape, and is three-dimensionally and periodically arranged, and the average value of the length of one unit of the repeating structure is 1 nm to 100 nm. A nanoheterostructure having a structure, a p-type semiconductor layer, and an n-type semiconductor layer are provided.

  In the nanoheterostructure pn junction element of the present invention, an end portion of a pn junction surface formed by the p-type semiconductor material and the n-type semiconductor material in the nanoheterostructure is the p-type semiconductor layer and the p-type semiconductor layer. The p-type semiconductor layer and the n-type semiconductor layer sandwich the nanoheterostructure so as to be in contact with the surface of at least one of the n-type semiconductor layers.

  Here, the state where the end of the pn junction surface is in contact with the surface of the semiconductor layer is when the shape of the inorganic component arranged three-dimensionally and periodically in the matrix is columnar (that is, In the case where the nano-heterostructure is a columnar structure), it means that the long axis of the columnar part is not parallel to the surface of the semiconductor layer. When the shape of the inorganic component arranged three-dimensionally and periodically in the matrix is layered (that is, when the nanoheterostructure is a layered structure), the interface of the layered part (pn junction surface) Means not parallel to the surface of the semiconductor layer. When the long axis of the columnar part or the interface of the layered part is parallel to the surface of the semiconductor layer, the effective area of the pn junction surface is equivalent to that of a conventional single junction pn junction element, and the photoelectric conversion characteristics of the pn junction element are sufficient. Does not improve.

  In the nanoheterostructure pn junction device of the present invention, the nanoheterostructure is a columnar structure or a layered structure from the viewpoint that the effective area of the pn junction surface is increased and the photoelectric conversion characteristics are further improved as compared with the conventional single junction pn junction device. In the case of a structure, the pn junction surface in the nanoheterostructure is preferably formed in a direction perpendicular to the surface of the semiconductor layer. That is, when the nano-heterostructure is a columnar structure, as shown in FIG. 2, the major axis of the columnar portion (1b) is perpendicular to the surface of the semiconductor layer (2 and / or 3). When the state is preferred and the nanoheterostructure is a layered structure, the interface (pn junction surface) of the layered portion (1c) is the surface of the semiconductor layer (2 and / or 3) as shown in FIG. The state which is perpendicular | vertical with respect to is preferable. When the shape of the inorganic component arranged three-dimensionally and periodically in the matrix is a gyroidal shape as shown in FIG. 4 (that is, when the nanoheterostructure is a gyroidal structure), Since the effective area of the pn junction surface necessarily increases as compared with the conventional single junction pn junction element, the photoelectric conversion characteristics are also improved.

  Such a nanoheterostructure pn junction element of the present invention comprises a nanostructure that could not be realized by a conventional manufacturing method, and the combination of a p-type semiconductor material and an n-type semiconductor material It is possible to obtain a nanoheterostructure having variously controlled arrangement, composition, structure scale, and the like. Therefore, according to the nano-heterostructure pn junction element of the present invention, dramatic improvements such as an interface increasing effect, a nano-size effect, durability, and the like over the conventional single-junction pn junction element are exhibited, resulting in high photoelectric conversion characteristics. Will come out.

As the p-type semiconductor material and the n-type semiconductor material constituting the nano-heterostructure in the nano-heterostructure pn junction element of the present invention, a p-type semiconductor material and an n-type semiconductor material used for known pn junction elements, respectively, may be used. For example, a known semiconductor material doped with a known impurity element can be used. Examples of the semiconductor material include group IV semiconductors (Si, G, etc.), group III-V semiconductors (GaAs, InP, GaN, etc.), group IV compound semiconductors (SiC, SiGe, etc.), and group I-III-VI semiconductors (CuInSe). _{2 and the} like). The p-type semiconductor material is obtained by doping such a semiconductor material with an impurity element having a lower valence than that of the semiconductor material. For example, boron (B) is added to a crystal made of a tetravalent element such as silicon (Si). ) And the like, and a crystal composed of a trivalent element such as gallium (Ga) doped with a divalent element such as magnesium (Mg). The n-type semiconductor material is obtained by doping the semiconductor material with an impurity element having a valence higher than that of the semiconductor material. For example, a crystal of a tetravalent element such as silicon (Si) or germanium (Ge). And those obtained by doping a pentavalent element such as arsenic (As) or a crystal composed of a trivalent element such as gallium (Ga) with a tetravalent element such as silicon (Si).

  The nanoheterostructure pn junction element of the present invention comprises the nanoheterostructure, a p-type semiconductor layer, and an n-type semiconductor layer. As described above, the end of the pn junction surface in the nanoheterostructure is the p The nanoheterostructure is sandwiched between the p-type semiconductor layer and the n-type semiconductor layer so as to be in contact with the surface of at least one of the n-type semiconductor layer and the n-type semiconductor layer.

  As the p-type semiconductor layer and the n-type semiconductor layer, a p-type semiconductor layer and an n-type semiconductor layer of a known pn junction element can be adopted, respectively. Such a semiconductor layer is obtained by doping a known semiconductor material with a known impurity element, and is formed using those exemplified in the p-type semiconductor material and the n-type semiconductor material constituting the nanoheterostructure. It is. In the present invention, the p-type semiconductor layer preferably contains the same kind of semiconductor material and impurity element as the p-type semiconductor material constituting the nanoheterostructure, and the n-type semiconductor layer includes the nanoheterostructure. A material containing the same kind of semiconductor material and impurity element as the n-type semiconductor material constituting the structure is preferable. By combining the p-type semiconductor layer and the p-type semiconductor material constituting the nano-heterostructure in this way, there is no barrier between the p-type semiconductor layer and the p-type semiconductor material, and the charges (holes) generated at the pn junction surface are eliminated. ) Movement tends to occur smoothly. Similarly, the n-type semiconductor material constituting the n-type semiconductor layer and the nano-heterostructure also tends to cause a smooth movement of charges (electrons). As a result, the nanoheterostructure pn junction element of the present invention exhibits high photoelectric conversion performance.

  In the nanoheterostructure pn junction element of the present invention, electrodes may be disposed on the surfaces of the p-type semiconductor layer and the n-type semiconductor layer. 5 to 6 are schematic views showing an example of the nanoheterostructure pn junction element of the present invention in which electrodes are arranged on a semiconductor layer. In the nanoheterostructure pn junction element of the present invention, as shown in FIG. 5, the electrode (4) is disposed on the surface opposite to the nanoheterostructure (1) side in one semiconductor layer (2), and the other The semiconductor layer (3) may be disposed on the surface of the nanoheterostructure (1) side, or, as shown in FIG. 6, in any of the semiconductor layers (2 and 3), the nanoheterostructure You may arrange | position on the surface on the opposite side to the body (1) side. Although there is no restriction | limiting in particular as said electrode, Well-known transparent electrodes, such as well-known metal electrodes, such as Au electrode, ITO transparent electrode, etc. are mentioned.

Next, a method for manufacturing such a nanoheterostructure pn junction element of the present invention will be described. The method for producing the nano-heterostructure pn junction element of the present invention includes:
A block copolymer formed by bonding at least a first polymer block component and a second polymer block component that are immiscible with each other; a first inorganic precursor that is one of a p-type semiconductor material precursor and an n-type semiconductor material precursor; A first step of preparing a raw material solution by dissolving a second inorganic precursor that is the other of the p-type semiconductor material precursor and the n-type semiconductor material precursor in a solvent;
At least a first polymer phase composed of the first polymer block component introduced with the first inorganic precursor; and a second polymer phase composed of the second polymer block component introduced with the second inorganic precursor; Phase-separation treatment for forming regularly arranged nanophase-separated structures by self-organization, and the p-type semiconductor material precursor and the n-type semiconductor material precursor as a p-type semiconductor material and an n-type semiconductor material, respectively. A conversion process for converting, and a removal process for removing the block copolymer from the nanophase-separated structure, wherein the p is contained in a matrix composed of one inorganic component of the p-type semiconductor material and the n-type semiconductor material. The other inorganic component of the n-type semiconductor material and the n-type semiconductor material is selected from the group consisting of a columnar shape, a gyroidal shape, and a layered shape In Jo, a second step of allowed to form on a nano-hetero structure are arranged three-dimensionally and periodically, p-type semiconductor layer and n-type semiconductor layer while the is first semiconductor layer of,
A second semiconductor layer which is the other of the p-type semiconductor layer and the n-type semiconductor layer is formed on the nanoheterostructure, and is formed by the p-type semiconductor material and the n-type semiconductor material in the nanoheterostructure. A third step of obtaining a nano-heterostructure pn junction element in which an end portion of the pn junction surface is in contact with the surface of at least one of the p-type semiconductor layer and the n-type semiconductor layer;
It is a method including. Below, each process is demonstrated.

[First step: Raw material solution preparation step]
This step is a step of preparing a raw material solution by dissolving a block copolymer described below and an inorganic precursor described below in a solvent.

  The block copolymer used in the present invention is formed by binding at least a first polymer block component and a second polymer block component. As a specific example of such a block copolymer, a polymer block component A having a repeating unit a (first polymer block component) and a polymer block component B having a repeating unit b (second polymer block component) are end to end. There are combined AB type and ABA type block copolymers having a structure of-(aa ... aa)-(bb ... bb)-. Further, a star shape in which one or more kinds of polymer block components extend radially from the center, or a shape in which other polymer components are suspended from the main chain of the block copolymer may be used.

  The polymer block components constituting the block copolymer used in the present invention are not particularly limited as long as they are immiscible with each other. Therefore, the block copolymer used in the present invention is preferably composed of polymer block components having different polarities. Specific examples of such a block copolymer include polystyrene-polymethyl methacrylate (PS-b-PMMA), polystyrene-polyethylene oxide (PS-b-PEO), polystyrene-polyvinylpyridine (PS-b-PVP), polystyrene-polyferrocese. Nyldimethylsilane (PS-b-PFS), polyisoprene-polyethylene oxide (PI-b-PEO), polybutadiene-polyethylene oxide (PB-b-PEO), polyethylethylene-polyethylene oxide (PEE-b-PEO), Polybutadiene-polyvinylpyridine (PB-b-PVP), polyisoprene-polymethyl methacrylate (PI-b-PMMA), polystyrene-polyacrylic acid (PS-b-PAA), polybutadiene-polymethyl methacrylate (PB-b-PMMA) and the like. Among them, the larger the difference in the polarity of the polymer block component, the greater the difference in the polarity of the precursor that can be introduced. Therefore, from the viewpoint of easy introduction of the precursor into each polymer block component, PS-b -PVP, PS-b-PEO, PS-b-PAA and the like are preferable.

  The molecular weight of the block copolymer and each polymer block component constituting the block copolymer may be appropriately selected according to the structure scale (size and spacing of columns, layers, etc.) and arrangement of the nanoheterostructure constituting the pn junction device of the present invention. . For example, it is preferable to use a block copolymer having a number average molecular weight of 1,000 to 10,000,000 (more preferably 1,000 to 1,000,000), and the structural scale tends to be smaller as the number average molecular weight is smaller. In addition, regarding the number average molecular weight of each polymer block component, by adjusting the molecular weight ratio of each polymer block component, etc., a desired nanophase separation structure obtained by self-organization in the nanophase separation structure formation step described later is desired. As a result, a nanoheterostructure having a structure in which inorganic components are arranged in a desired form can be obtained. Further, it is preferable to use a block copolymer that is easily decomposed by heat treatment (baking) or light irradiation described later, or a block copolymer that is easily removed by a solvent.

  The p-type semiconductor material precursor and the n-type semiconductor material precursor used in the present invention are not particularly limited as long as the p-type semiconductor material and the n-type semiconductor material precursor are inorganic precursors that can be formed by the conversion process described later. . Specifically, the metal or metalloid salt (for example, carbonate, nitrate, phosphate, sulfate, acetate, chloride, organic acid salt (acrylic acid) constituting the p-type semiconductor material and the n-type semiconductor material. Acid salt)), C1-C4 alkoxide (for example, methoxide, ethoxide, propoxide, butoxide) containing the metal or metalloid, complex of the metal or metalloid (for example, acetylacetonate complex) An organic metal compound or an organic metalloid compound containing the metal or the metalloid (for example, a phenyl group, a long-chain hydrocarbon chain having 5 or more carbon atoms, a cyclooctatetraene ring, a cyclopentadienyl ring, and an amino group) Those having at least one structure selected from the group consisting of: Such a p-type semiconductor material precursor and an n-type semiconductor material precursor are selected according to the combination of the p-type semiconductor material and the n-type semiconductor material constituting the target nanoheterostructure, One or more kinds are appropriately selected and used so as to satisfy the conditions.

  The solvent used in the present invention is not particularly limited as long as it can dissolve the block copolymer to be used and the first and second inorganic precursors. For example, acetone, tetrahydrofuran (THF), toluene, propylene glycol monomethyl Examples include ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), chloroform, and benzene. Such a solvent may be used individually by 1 type, and 2 or more types may be mixed and used for it.

  In this specification, “dissolution” is a phenomenon in which a substance (solute) dissolves in a solvent to form a uniform mixture (solution). When at least a part of the solute becomes an ion after dissolution, Examples include a case where the molecule is present without being dissociated into ions, a case where molecules or ions are associated and present, and the like.

In the present invention, the first polymer block component, the first inorganic precursor which is one of the p-type semiconductor material precursor and the n-type semiconductor material precursor, the second polymer block component and the precursor And a second inorganic precursor that is the other of the first inorganic block precursors, and a difference in solubility parameter from the first polymer block component is 2 (cal / cm ³ ) ^1/2 or less. It is preferable to use a combination of a precursor and a second inorganic precursor having a solubility parameter difference of 2 (cal / cm ³ ) ^1/2 or less between the second polymer block component. In the step of forming a nanophase separation structure to be described later by using a combination of the first inorganic precursor and the second inorganic precursor that satisfy such conditions, the first inorganic precursor is contained in the first polymer block component. However, a nanophase separation structure is formed together with the self-assembly of the block copolymer in a state where the second inorganic precursor is sufficiently introduced in the second polymer block component, and the inorganic precursor is three-dimensionally nanoscaled. Arranged with periodicity.

  The difference in solubility parameter between the first polymer block component and the first inorganic precursor used in the present invention is preferably smaller than the difference in solubility parameter between the first polymer block component and the second inorganic precursor. . The difference in solubility parameter between the second polymer block component and the second inorganic precursor is preferably smaller than the difference in solubility parameter between the second polymer block component and the first inorganic precursor. Furthermore, it is more preferable to satisfy both of these conditions.

Furthermore, the first inorganic precursor used in the present invention preferably has a solubility parameter difference of more than 2 (cal / cm ³ ) ^{1/2 with} respect to the second polymer block component. The second inorganic precursor preferably has a solubility parameter difference of more than 2 (cal / cm ³ ) ^{1/2 with} respect to the first polymer block component. Furthermore, it is more preferable to satisfy both of these conditions.

  By using the first inorganic precursor and the second inorganic precursor that satisfy such conditions in combination, in the step of forming a nanophase separation structure described later, the second inorganic precursor as an impurity in the first polymer block component There is a tendency that a part of the precursor and a part of the first inorganic precursor are introduced as impurities into the second polymer block component more reliably, and the resulting matrix in the nanoheterostructure There is a tendency that the purity of the inorganic component constituting and / or the purity of the inorganic component arranged in the matrix is further improved.

  As a combination of the first and second polymer block components and the first and second inorganic precursors satisfying such conditions, the first polymer block component is selected from the group consisting of a polystyrene component, a polyisoprene component and a polybutadiene component. At least one polar polymer block component having at least one polar selected from the group consisting of a polymethyl methacrylate component, a polyethylene oxide component, a polyvinyl pyridine component, and a polyacrylic acid component. A large polymer block component, wherein the first inorganic precursor is at least one small polar inorganic precursor selected from the group consisting of the organometallic compound and the organometallic compound, and the second inorganic precursor is the Metal or metal salt, metal Preferred combinations are a great inorganic precursor of at least one polar selected from the group consisting of the 1 to 4 carbon atoms containing a semimetal alkoxide, and the metal or the semimetal acetylacetonato complex.

In addition, at least one (more preferably both) of the first inorganic precursor and the second inorganic precursor has a solubility parameter difference of 2 (cal / cm ³ ) ^1/2 or less with the solvent used. It is preferable. By using the first inorganic precursor and / or the second inorganic precursor satisfying such conditions, the inorganic precursor is more reliably dissolved in the solvent, and the polymer block is formed in the step of forming the nanophase separation structure described later. Inorganic precursors tend to be more reliably introduced into the components.

  Furthermore, the ratio of the solute (block copolymer, first inorganic precursor and second inorganic precursor) in the obtained raw material solution is not particularly limited, but when the total amount of the raw material solution is 100% by mass, the total amount of the solute is It is preferable to set it as about 0.1-30 mass%, and it is more preferable to set it as 0.5-10 mass%. Moreover, since the quantity of each inorganic precursor introduce | transduced into each polymer block component is adjusted by adjusting the usage-amount of the 1st and 2nd inorganic precursor with respect to a block copolymer, p-type in the obtained nanoheterostructure The ratio between the semiconductor material and the n-type semiconductor material, the structural scale thereof (size and spacing of columns, layers, etc.) can be set to a desired level.

[Second step: Nanoheterostructure formation step]
This step includes a phase separation process, a conversion process, and a removal process, which will be described in detail below. A nanoheterostructure composed of a p-type semiconductor material and an n-type semiconductor material is converted into a p-type semiconductor layer and an n-type semiconductor layer. This is a step of forming on one of the semiconductor layers.

First, the raw material solution prepared in the first step includes a block copolymer, a p-type semiconductor material precursor, and an n-type semiconductor material precursor. In the present invention, the first polymer block component and the p-type are used. A first inorganic precursor that is one of a semiconductor material precursor and an n-type semiconductor material precursor, and a second inorganic precursor that is the other of the second polymer block component and the precursor, respectively. Used, and further, the difference in solubility parameter between the first polymer block component and the first polymer block component is less than 2 (cal / cm ³ ) ^1/2 and the second polymer block component. Is preferably used in combination with a second inorganic precursor having 2 (cal / cm ³ ) ^1/2 or less. Thereby, a 1st inorganic precursor and a 2nd inorganic precursor exist in the state fully introduced in the 1st polymer block component and the 2nd polymer block component, respectively. Therefore, the first polymer phase consisting of the first polymer block component introduced with the first inorganic precursor and the second inorganic precursor are introduced by a phase separation process that forms a nanophase separation structure by self-organization of the block copolymer. The inorganic precursor is three-dimensionally arranged by regularly arranging the second polymer phase composed of the second polymer block component, and forming the nanophase separation structure into a columnar structure, a gyroidal structure, or a layered structure. Arranged with periodicity of scale.

  Such a phase separation treatment is not particularly limited, but the block copolymer is self-assembled by heat treatment at a temperature higher than the glass transition point of the block copolymer to be used, and a phase separation structure is obtained.

  Next, in the present invention, the p-type semiconductor material precursor and the n-type semiconductor material precursor are converted into a p-type semiconductor material and an n-type semiconductor material, respectively, with respect to the nanophase-separated structure formed by the phase separation process. And a removal treatment for removing the block copolymer from the nanophase separation structure. The p-type semiconductor material precursor and the n-type semiconductor material precursor are converted into a p-type semiconductor material and an n-type semiconductor material, respectively, by the conversion process, and the block copolymer is removed by the removal process, thereby nanophase separation. Depending on the type (shape) of the structure, the other inorganic component is three-dimensionally specified in the shape of one of the inorganic components of the p-type semiconductor material and n-type semiconductor material in the form of a column, gyroid, or layer. Nano-heterostructures arranged with nano-scale periodicity are obtained.

  Such conversion treatment may be a step of converting the inorganic precursor to an inorganic component by heating at a temperature at which the inorganic precursor is converted to the inorganic component, or dehydrating and condensing the inorganic precursor. It may be a step of converting into an inorganic component.

  The removal treatment may be a step of decomposing the block copolymer by heat treatment (baking) at a temperature higher than the temperature at which the block copolymer decomposes, but a step of dissolving and removing the block copolymer with a solvent, ultraviolet light, etc. It may be a step of decomposing the block copolymer by light irradiation.

  Furthermore, in the second step of the present invention, the phase separation treatment, the heat treatment (calcination) is performed on the raw material solution prepared in the first step at a temperature higher than the temperature at which the block copolymer decomposes, The conversion process and the removal process can be performed by a single heat treatment. As described above, in order to complete the phase separation process, the conversion process, and the removal process by a single heat treatment, the temperature varies from 300 to 1200 ° C. (more preferably from 400 to 1200 ° C.) depending on the type of block copolymer and inorganic precursor used. 900 ° C.) for about 0.1 to 50 hours.

  Such heat treatment may be performed in an inert gas atmosphere (eg, nitrogen gas), in an oxidizing gas atmosphere (eg, air), or in a reducing gas atmosphere (eg, hydrogen). By converting the inorganic precursor into an inorganic component and removing the block copolymer in an inert gas atmosphere, the nanoscale three-dimensional periodic structure tends to be more reliably maintained. In addition, by converting an inorganic precursor into an inorganic component in an oxidizing gas atmosphere, a nanoheterostructure including a p-type semiconductor material and an n-type semiconductor material made of a metal or metalloid oxide can be obtained. Furthermore, by converting an inorganic precursor into an inorganic component in a reducing gas atmosphere, a nanoheterostructure including a p-type semiconductor material and an n-type semiconductor material made of a metal or a semimetal can be obtained. The heat treatment conditions in such an inert gas atmosphere, oxidizing gas atmosphere, or reducing gas atmosphere are not particularly limited, but are 300 to 1200 ° C. (more preferably 400 to 900 ° C.) for 0.1 to 50 hours. A degree of treatment is preferred.

  Further, after the heat treatment or during the heat treatment, by a known method, a treatment for carbonizing an inorganic component using an argon atmosphere or the like, a treatment for nitriding an inorganic component using an ammonia atmosphere or the like, a boron carbide-containing atmosphere, or the like A treatment for boriding an inorganic component may be further performed by using.

  In the manufacturing method of the nanoheterostructure pn junction element of the present invention, the nanoheterostructure obtained in this way is formed on the first semiconductor layer which is one of the p-type semiconductor layer and the n-type semiconductor layer. At this time, the nanoheterostructure is formed into the first semiconductor so that the end of the pn junction surface formed by the p-type semiconductor material and the n-type semiconductor material in the nanoheterostructure is in contact with the surface of the first semiconductor layer. It is preferable to form it on a layer, and in some cases, it is necessary to form it. That is, there is no particular limitation on the nanoheterostructure having a gyroidal structure, but at least the major axis of the columnar part or the interface of the layered part is on the surface of the first semiconductor layer for the nanoheterostructure having a columnar structure or a layered structure. It is necessary to form it so that it does not become parallel to it. Further, it is more preferable that the nano-heterostructure having a columnar structure or a layered structure is formed on the first semiconductor layer so that the pn junction surface is perpendicular to the surface of the first semiconductor layer.

  As a method of forming the nanoheterostructure on the first semiconductor layer, (i) a nanoheterostructure according to the present invention is obtained by performing the phase separation process, the conversion process, and the removal process in advance. And (ii) applying the raw material solution on the surface of the first semiconductor layer to form a layer made of the raw material solution, and then performing the phase separation treatment, Examples include a method of directly forming the nanoheterostructure according to the present invention on the first semiconductor layer by performing the conversion treatment and the removal treatment. Among these, the method (ii) is preferable from the viewpoint of adhesion between the nanoheterostructure and the first semiconductor layer. Examples of the method for applying the raw material solution include brushing, spraying, dipping, spin, and curtain flow.

  In the case of forming a columnar or layered nanoheterostructure, in the method (i), the end surfaces of the columnar part and the layered part are exposed on the surface, and the long axis of the columnar part and the interface of the layered part are on the surface. It is preferable to produce a nanoheterostructure that is perpendicular to the first semiconductor layer and to stack the nanoheterostructure on the first semiconductor layer. In the method (ii), the upper surface of the layer made of the raw material solution is exposed to a vapor of a good solvent for at least one of the p-type semiconductor material precursor and the n-type semiconductor material precursor. However, it is preferable to perform the phase separation treatment. By these methods, the pn junction surface in the nanoheterostructure can be formed in a direction perpendicular to the surface of the first semiconductor layer. Examples of the good solvent include those exemplified as the solvent for the raw material solution. Moreover, as temperature at the time of exposing to the vapor | steam of the said good solvent, the temperature below the boiling point of the solvent in the said raw material solution is preferable. When the exposure temperature exceeds the upper limit, the volatilization of the solvent is accelerated, and it tends to be difficult to form the pn junction surface in a direction perpendicular to the surface of the first semiconductor layer.

  In the first semiconductor layer used in the present invention, the first semiconductor layer itself may be a substrate or may be formed on the substrate. When the first semiconductor layer is formed on the substrate, the substrate is not particularly limited. For example, various electrode substrates such as a metal electrode substrate such as an AU electrode substrate and a transparent electrode substrate such as an ITO electrode substrate are used. be able to. A method for forming the first semiconductor layer on such a substrate is not particularly limited. For example, chemical vapor deposition (CVD), metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE) And other known film forming methods.

[Third step: semiconductor layer forming step]
This step is a step of forming a second semiconductor layer which is the other of the p-type semiconductor layer and the n-type semiconductor layer on the nanoheterostructure.

  The nanoheterostructure pn of the present invention in which the nanoheterostructure is sandwiched between the p-type semiconductor layer and the n-type semiconductor layer by forming the second semiconductor layer on the nanoheterostructure formed in the second step. A junction element can be obtained. At this time, it is preferable to form the second semiconductor layer on the nanoheterostructure so that the end of the pn junction surface in the nanoheterostructure is in contact with the surface of the second semiconductor layer. It is necessary to show them. That is, there is no particular limitation on the nanoheterostructure having a gyroidal structure, but on the nanoheterostructure having a columnar structure or a layered structure, at least the major axis of the columnar section or the interface of the layered section is the surface of the second semiconductor layer. Therefore, it is necessary to form the second semiconductor layer so as not to be parallel to each other. More preferably, the second semiconductor layer is formed on the columnar or layered nanoheterostructure so that the pn junction surface is perpendicular to the surface of the second semiconductor layer.

  The method for forming the second semiconductor layer on the nanoheterostructure is not particularly limited, but chemical vapor deposition (CVD), metal organic chemical vapor deposition (MOCVD), molecular on the surface of the nanoheterostructure is not limited. It is preferable to form the second semiconductor layer using a known film forming method such as a line epitaxial method (MBE method).

  In the method for producing a nano-heterostructure pn junction element of the present invention, it is further preferable to form electrodes on the first and second semiconductor layers by a known method. Examples of such electrodes include metal electrodes such as Au electrodes and transparent electrodes such as ITO electrodes.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

Example 1
10 g of polystyrene-b-poly (4-vinylpyridine) (PS-b-P4VP, number average molecular weight of PS component: 80 × 10 ³ , number average molecular weight of P4VP component: 42 × 10 ³ ) as a block copolymer, p-type 0.2 mg of acetylacetonate magnesium (Mg (acac) ₂ ) and 8.8 g of acetylacetonate gallium (Ga (acac) ₃ ) as Mg-GaN precursors (Mg precursor and Ga precursor) which are semiconductor material precursors And 0.3 mg of phenylsilane (PhSiH ₃ ) and trisdimethylaminogallium (Ga (N (CH ₃ ) ₂ ) ₃ as Si-GaN precursors (Si precursor and Ga precursor) which are n-type semiconductor material precursors 9.6 g was dissolved in 1000 mL of toluene to obtain a raw material solution.

Next, on the surface of an n-Si-GaN substrate (Si-doped GaN substrate, thickness: 1.2 μm) which is an n-type semiconductor layer, the thickness of the obtained raw material solution after heat treatment becomes 0.8 μm. Then, the semiconductor material precursor was oriented perpendicular to the n-type semiconductor layer by holding at 50 ° C. for 20 hours in the presence of toluene vapor. Then, the inorganic structure was produced on the said n-type semiconductor layer by heat-processing at 650 degreeC under ammonia stream for 5 hours. The contact area between the n-type semiconductor layer and the inorganic structure was 25 mm ² .

When the obtained inorganic structure was observed using a transmission electron microscope (TEM), as shown in FIG. 7, in an n-Si-GaN (Si-doped GaN) matrix that is an n-type semiconductor material, It was confirmed that the columnar p-Mg-GaN (GaN doped with Mg), which is a p-type semiconductor material, is a nanoheterostructure (1) in which three-dimensionally and periodically arranged. It was also confirmed that the pn junction surface in the nanoheterostructure (1) was formed perpendicular to the surface of the n-type semiconductor layer (3). Incidentally, the black portions in FIG. 7 _{(n C)} is n-Si-GaN matrix white part _{(p C)} is a columnar p-Mg-GaN.

  Moreover, when the small-angle X-ray diffraction pattern was measured about the obtained inorganic structure using the small-angle X-ray-diffraction measuring apparatus (Rigaku company make, brand name: NANO-Viewer), the space | interval (d) of a periodic structure is 32 nm. In addition, a diffraction peak pattern (ratio of diffraction spectrum size (q) at the peak position) characteristic to the columnar structure was confirmed.

  Next, a p-Mg-GaN layer (a GaN layer doped with Mg) is formed as a p-type semiconductor layer on the surface of the nanoheterostructure by a CVD method so as to have a thickness of 1.2 μm. A nanoheterostructure pn junction element Got. Au electrode pads were formed by CVD on the p-type semiconductor layer and the n-type semiconductor layer of the nanoheterostructure pn junction element, and the nanoheterostructure pn junction element (light emitting diode) shown in FIG. 5 was produced. When a forward current of 50 mA was applied to the obtained light emitting diode, the light emission output was 2.5 mW.

(Example 2)
As the block copolymer, 10 g of PS-b-P4VP in which the number average molecular weight of the PS component is 100 × 10 ³ and the number average molecular weight of the P4VP component is 103 × 10 ³ is used, and Mg (GaN) is used as the Mg-GaN precursor. In the same manner as in Example 1 except that 0.4 mg of acac) ₂ and 17.5 g of Ga (acac) ₃ were used, an inorganic layer was formed on the n-type semiconductor layer (n-Si-GaN substrate, thickness: 1.2 μm). A structure (thickness: 0.6 μm, contact area with the n-type semiconductor layer: 25 mm ² ) was produced.

When the obtained inorganic structure was observed using a transmission electron microscope (TEM) similarly to Example 1, as shown in FIG. 8, n-Si-GaN (Si-doped n-type semiconductor material) was used. GaN) and p-Mg-GaN (GaN doped with Mg), which is a p-type semiconductor material, are periodically and alternately arranged to form a nanoheterostructure (1) forming a multilayer structure. It was. It was also confirmed that the pn junction surface in the nanoheterostructure (1) was formed perpendicular to the surface of the n-type semiconductor layer (3). Incidentally, the black portions in FIG. 8 _{(n L)} is a layered n-Si-GaN, white part _{(p L)} is a layered p-Mg-GaN.

  Further, when the small-angle X-ray diffraction pattern of the obtained inorganic structure was measured in the same manner as in Example 1, the interval (d) of the periodic structure was 24 nm, and a diffraction peak pattern characteristic of the layered structure (the peak position) The ratio of the size (q) of the diffraction spectrum was confirmed.

  Next, a p-Mg-GaN layer (thickness: 1.2 μm) was produced as a p-type semiconductor layer on the surface of the nanoheterostructure in the same manner as in Example 1, and an electrode pad was further formed. The light emitting diode shown was made. When a forward current of 50 mA was applied to the obtained light emitting diode in the same manner as in Example 1, the light emission output was 2.1 mW.

(Comparative Example 1)
On the surface of the n-type semiconductor layer (n-Si-GaN substrate, thickness: 1.2 μm), an n-Si-GaN film (Si-doped GaN film, carrier concentration: 1.6 × 10 ¹⁸ ) as an n-type semiconductor material. cm ⁻³ , area: 25 mm ² , thickness: 0.3 μm) and p-Mg-GaN film (Mg-doped GaN film, carrier concentration: 8.2 × 10 ¹⁸ cm ⁻ ) as a p-type semiconductor material. ³ , area: 25 mm ² , thickness: 0.3 μm). A p-Mg-GaN layer (thickness: 1.2 μm) is produced as a p-type semiconductor layer on the surface of the laminate in the same manner as in Example 1, and an electrode pad is formed to form a light emitting diode as shown in FIG. Was made. When a forward current of 50 mA was applied to the obtained light emitting diode in the same manner as in Example 1, the light emission output was 0.7 mW.

  As described above, according to the present invention, the other inorganic component is three-dimensionally predetermined in a predetermined shape in a matrix composed of one inorganic component of the p-type semiconductor material and the n-type semiconductor material. Thus, it is possible to obtain a nanoheterostructure pn junction element in which the nanoheterostructures periodically arranged in the structure are sandwiched between the p-type semiconductor layer and the n-type semiconductor layer.

  Such a nano-heterostructure pn junction element of the present invention has a structure that could not be realized by a conventional manufacturing method, and a combination of a p-type semiconductor material and an n-type semiconductor material It is possible to obtain a nanoheterostructure having various arrangements, compositions, structural scales, and the like.

  Such a pn junction element having a nano-heterostructure exhibits a dramatic improvement in the interface enhancement effect, nanosize effect, durability, and the like over the conventional single-junction pn junction element, and as a result, photoelectric conversion such as luminous efficiency. Excellent properties. Therefore, the nanoheterostructure pn junction element of the present invention is useful as a photoelectric conversion element such as a light emitting element or a solar cell, and a rectifying element such as a diode or a transistor.

1: nanoheterostructure, 1a: matrix part, 1b: columnar part, 1c: layered part, 1d: gyroidal part, 2: p-type semiconductor layer (or n-type semiconductor layer), 3: n-type semiconductor layer (or p-type semiconductor layer), 4: electrode, 5: pn junction layer, 5a: p-type semiconductor material (or n-type semiconductor material), 5b: n-type semiconductor material (or p-type semiconductor material), n _C : columnar n-type Semiconductor material, n _L : layered n-type semiconductor material, p _C : p-type semiconductor material matrix, p _L : layered p-type semiconductor material.

Claims (12)

A group consisting of one inorganic component of a p-type semiconductor material and an n-type semiconductor material, wherein the other inorganic component of the p-type semiconductor material and the n-type semiconductor material consists of a columnar shape, a gyroid shape, and a layer shape A nano-heterostructure having a three-dimensional periodic structure in which the average value of the length of one unit of the repeating structure is 1 nm to 100 nm, which is three-dimensionally and periodically arranged in a shape selected from , A p-type semiconductor layer, and an n-type semiconductor layer,
An end portion of a pn junction surface formed by the p-type semiconductor material and the n-type semiconductor material in the nanoheterostructure is at least one of the p-type semiconductor layer and the n-type semiconductor layer. The nano-heterostructure pn junction element, wherein the p-type semiconductor layer and the n-type semiconductor layer sandwich the nanoheterostructure so as to be in contact with the surface. The shape of the inorganic component arranged three-dimensionally and periodically in the matrix is columnar or layered,
2. The pn junction surface in the nanoheterostructure is formed in a direction perpendicular to a surface of at least one of the p-type semiconductor layer and the n-type semiconductor layer. A nano-heterostructure pn junction element according to 1.   3. The nanoheterostructure pn junction element according to claim 1, wherein the p-type semiconductor layer contains a semiconductor material and an impurity element of the same type as the p-type semiconductor material in the nanoheterostructure.   The said n-type semiconductor layer contains the same kind of semiconductor material and impurity as the n-type semiconductor material in the said nanoheterostructure, The one as described in any one of Claims 1-3 characterized by the above-mentioned. Nano-heterostructure pn junction element. A block copolymer formed by bonding at least a first polymer block component and a second polymer block component that are immiscible with each other; a first inorganic precursor that is one of a p-type semiconductor material precursor and an n-type semiconductor material precursor; A first step of preparing a raw material solution by dissolving a second inorganic precursor that is the other of the p-type semiconductor material precursor and the n-type semiconductor material precursor in a solvent;
At least a first polymer phase composed of the first polymer block component introduced with the first inorganic precursor; and a second polymer phase composed of the second polymer block component introduced with the second inorganic precursor; Phase-separation treatment for forming regularly arranged nanophase-separated structures by self-organization, and the p-type semiconductor material precursor and the n-type semiconductor material precursor as a p-type semiconductor material and an n-type semiconductor material, respectively. A conversion process for converting, and a removal process for removing the block copolymer from the nanophase-separated structure, wherein the p is contained in a matrix composed of one inorganic component of the p-type semiconductor material and the n-type semiconductor material. The other inorganic component of the n-type semiconductor material and the n-type semiconductor material is selected from the group consisting of a columnar shape, a gyroidal shape, and a layered shape In Jo, a second step of allowed to form on a nano-hetero structure are arranged three-dimensionally and periodically, p-type semiconductor layer and n-type semiconductor layer while the is first semiconductor layer of,
A second semiconductor layer which is the other of the p-type semiconductor layer and the n-type semiconductor layer is formed on the nanoheterostructure, and is formed by the p-type semiconductor material and the n-type semiconductor material in the nanoheterostructure. A third step of obtaining a nano-heterostructure pn junction element in which an end portion of the pn junction surface is in contact with the surface of at least one of the p-type semiconductor layer and the n-type semiconductor layer;
The manufacturing method of the nanoheterostructure pn junction element characterized by including this.   In the second step, a nanoheterostructure in which the shape of the inorganic component arranged three-dimensionally and periodically in the matrix is columnar or layered, and the pn junction surface in the nanoheterostructure is the first 6. The method for producing a nanoheterostructure pn junction element according to claim 5, wherein the nanoheterostructure pn junction element is formed on the first semiconductor layer so as to be perpendicular to the surface of the semiconductor layer.   After forming the layer made of the raw material solution on the first semiconductor layer, the upper surface of the layer made of the raw material solution is formed on at least one of the p-type semiconductor material precursor and the n-type semiconductor material precursor. 7. The pn junction surface is formed in a direction perpendicular to the surface of the first semiconductor layer by performing the phase separation treatment while being exposed to a vapor of a good solvent for the inorganic precursor. A method for producing the described nanoheterostructure pn junction element.   In the third step, the pn junction surface in the nanoheterostructure is formed on the nanoheterostructure in which the shape of the inorganic component arranged three-dimensionally and periodically in the matrix is columnar or layered. The method of manufacturing a nanoheterostructure pn junction element according to any one of claims 5 to 7, wherein the second semiconductor layer is formed so as to be perpendicular to the surfaces of the two semiconductor layers. . The difference in solubility parameter between the first inorganic precursor and the first polymer block component is 2 (cal / cm ³ ) ^1/2 or less, and the solubility between the second inorganic precursor and the second polymer block component The method for producing a nano-heterostructure pn junction element according to any one of claims 5 to 8, wherein the difference in parameters is 2 (cal / cm ³ ) ^1/2 or less.   The solubility parameter difference between the first polymer block component and the first inorganic precursor is smaller than the solubility parameter difference between the first polymer block component and the second inorganic precursor. The manufacturing method of the nanoheterostructure pn junction element as described in any one of 5-9.   The difference in solubility parameter between the second polymer block component and the second inorganic precursor is smaller than the difference in solubility parameter between the second polymer block component and the first inorganic precursor. The manufacturing method of the nanoheterostructure pn junction element as described in any one of 5-10. The block copolymer comprises at least one first polymer block component selected from the group consisting of a polystyrene component, a polyisoprene component and a polybutadiene component, and a polymethyl methacrylate component, a polyethylene oxide component, a polyvinyl pyridine component and a polyacrylic acid component. And at least one second polymer block component selected from the group consisting of:
The first inorganic precursor has at least one structure selected from the group consisting of a phenyl group, a long hydrocarbon chain having 5 or more carbon atoms, a cyclooctatetraene ring, a cyclopentadienyl ring, and an amino group. , At least one of an organometallic compound and an organometalloid compound,
The second inorganic precursor is at least one selected from the group consisting of metal or metalloid salts, metal or metalloid alkoxides having 1 to 4 carbon atoms, and metal or metalloid acetylacetonate complexes. is there,
The method for producing a nano-heterostructure pn junction element according to any one of claims 5 to 11.