Shortwave infrared inas nanocrystal material and method for producing same

Abstract

An embodiment of the present invention provides an InAs nanocrystal material and a method for producing same. According to an embodiment of the present invention, a nanocrystal material having excellent optical and electrical properties in a shortwave infrared region is provided. The nanocrystal material has a band gap in the range of 1100 to 1847 nm, which is the near-infrared region, and thus can be used for high-performance infrared devices in various fields of application.

Description

Short-wave infrared INAS nanocrystalline material and manufacturing method

[0001] The present invention relates to an indium arsenide (InAs) nanocrystalline material and a method for manufacturing the same.

[0002] Colloidal quantum dot-based semiconductor nanocrystalline materials can exhibit excellent optical and electrical properties in the infrared region as well as the visible light region through the control of nanocrystal size.

[0003] However, lead and mercury-based nanocrystals, which are primarily used as infrared absorbing materials, fall under Class I of the Restriction of Hazardous Substances Directive (RoHS) (lead, mercury, etc.), so there are limitations on commercialization.

[0004] Indium arsenide (InAs) quantum dot materials are attracting attention as an alternative to address these problems; however, conventional InAs nanocrystals generally have a spherical shape, which leads to strong quantum confinement effects, making it difficult to extend the bandgap to the short-wave infrared range.

[0005] In addition, conventional technology has economic limitations, such as requiring large amounts of expensive precursors and long synthesis times to increase size to short-wave infrared.

[0006] [Prior Art Literature]

[0007] (Patent Document 1) Korean Published Patent 10-2020-0130124

[0008] The present invention relates to an indium arsenide (InAs) nanocrystalline material capable of exhibiting excellent optical and electrical properties in the short-wave infrared (SWIR) region as a method to solve the problems of the aforementioned prior art, and a method for manufacturing the same.

[0009] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0010] To achieve the above technical problem, one embodiment of the present invention provides an InAs nanocrystalline material.

[0011] An InAs nanocrystalline material according to one embodiment of the present invention is a nanocrystalline material having excellent optical and electrical properties in the short-wave infrared region, and is characterized by having a band gap in the range of 1100 to 1847 nm and a tetrahedral structure including a {111} plane as an exposed plane.

[0012] In an embodiment of the present invention, the nanocrystalline material may be an InAs nanocrystalline material characterized by having a tetrahedral side length of 5.30 nm to 13.4 nm at a band gap of 1.11 eV to 0.67 eV.

[0013] Another embodiment of the present invention for achieving the above technical problem provides a method for manufacturing an InAs nanocrystalline material.

[0014] An InAs nanocrystalline material according to one embodiment of the present invention is characterized by comprising: a step (S100) of preparing a first solution comprising an indium precursor and a first solvent; a step (S200) of preparing a second solution comprising an amino-arsine-based precursor, a reaction relaxant, and a second solvent; and a step (S300) of mixing the first solution and the second solution and adding a reducing agent to produce an InAs nanocrystalline material.

[0015] In an embodiment of the present invention, the first solvent may be selected from the group consisting of oleylamine, dodecylamine, hexadecylamine, octadecylamine, octylamine, trioctylamine, and combinations thereof, and may be a method for preparing an InAs nanocrystalline material.

[0016] In an embodiment of the present invention, the aminoarsine-based precursor may be a method for manufacturing an InAs nanocrystalline material, characterized in that it has a chemical formula represented as As((NR2)3), and R is an alkyl group having 1 to 10 carbon atoms.

[0017] In an embodiment of the present invention, the method for manufacturing an InAs nanocrystalline material may be characterized in that the reaction relaxant is lithium bis(trimethylsilyl)amide.

[0018] In an embodiment of the present invention, the lithium bis(trimethylsilyl)amide may be added to satisfy the range 0 < [LiHMDS] / [In] < 1 with the indium element of the indium precursor, and the method for manufacturing an InAs nanocrystalline material may be a method.

[0019] In an embodiment of the present invention, the mixing may be a method for manufacturing an InAs nanocrystalline material, characterized in that it is performed under a temperature condition of 200 ℃ to 350 ℃.

[0020] In an embodiment of the present invention, the reducing agent may be a method for manufacturing an InAs nanocrystalline material characterized by including diisobutylaluminum hydride.

[0021] In an embodiment of the present invention, the method for manufacturing an InAs nanocrystalline material may be characterized in that the reducing agent is added in an amount of 0 to 6 equiv relative to the concentration of the indium precursor.

[0022] According to an embodiment of the present invention, the quantum confinement effect is weakened through a tetrahedral structure having a {111} exposed surface, thereby enabling the optimization of the bandgap in the near-infrared band.

[0023] In addition, when a thin film is formed using the InAs nanocrystalline material of the present invention, the high volume fraction of the InAs core can increase the light absorption rate and reduce optical loss.

[0024] In addition, it is capable of mass production through a low-cost colloidal synthesis process, which enhances commercial applicability and allows it to be utilized as a high-performance infrared device in various application fields such as infrared sensors, communication devices, and medical imaging devices.

[0025] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description of the invention or the claims.

[0026] FIG. 1 is a flowchart schematically illustrating a method for manufacturing an InAs nanocrystalline material according to one embodiment of the present invention.

[0027] FIG. 2 is a drawing showing an InAs nanocrystalline material according to one embodiment of the present invention.

[0028] FIG. 3 is a schematic diagram showing a method for manufacturing an InAs nanocrystalline material according to one embodiment of the present invention.

[0029] Figure 4 is a HAADF-STEM image of a nanocrystalline material prepared according to the method for preparing an InAs nanocrystalline material according to one embodiment of the present invention.

[0030] Figure 5 is a diagram showing the results of InAs nanocrystal growth with and without the addition of LiHMDS additive.

[0031] Figure 6 is a graph showing the results of transamination inhibition with and without the addition of LiHMDS additive.

[0032] FIG. 7 is a diagram showing the crystal form of a nanocrystal manufactured according to the method for manufacturing InAs nanocrystals according to one embodiment of the present invention.

[0033] FIG. 8 is a diagram showing the absorption spectrum according to the crystal form of nanocrystals manufactured according to the method for manufacturing InAs nanocrystals according to one embodiment of the present invention.

[0034] FIG. 9 is a diagram showing the absorption spectrum according to the edge length of an InAs nanocrystal according to one embodiment of the present invention.

[0035] FIG. 10 is a HAADF-STEM image of an InAs nanocrystal according to one embodiment of the present invention.

[0036] FIG. 11 is a diagram showing the XRD pattern of InAs nanocrystals according to one embodiment of the present invention.

[0037] FIG. 12 is an experimental / simulated STEM image of an InAs nanocrystal according to one embodiment of the present invention.

[0038] FIG. 13 is a mobility curve of a tetrahedral InAs nanocrystal (solid line) and a spherical InAs nanocrystal (dotted line) according to one embodiment of the present invention.

[0039] Figure 14a is a diagram showing the 2D GISAXS pattern for spherical InAs nanocrystals.

[0040] FIG. 14b is a diagram showing a 2D GISAXS pattern for a tetrahedral InAs nanocrystal according to one embodiment of the present invention.

[0041] FIG. 15 is a horizontal cross-sectional view of a tetrahedral InAs nanocrystal and a spherical InAs nanocrystal in the Yoneda region according to one embodiment of the present invention.

[0042] FIG. 16a is a diagram showing the real part of the dielectric function of a tetrahedral InAs nanocrystalline film and a spherical InAs nanocrystalline film according to one embodiment of the present invention.

[0043] FIG. 16b is a diagram showing the imaginary part of the dielectric function of a tetrahedral InAs nanocrystal film and a spherical InAs nanocrystal film according to one embodiment of the present invention.

[0044] FIG. 16c is a transition graph of a tetrahedral InAs nanocrystal film according to one embodiment of the present invention.

[0045] Figure 16d is a transition graph of a spherical InAs nanocrystalline film.

[0046] FIG. 17a is a drawing showing a phototransistor including InAs nanocrystals according to one embodiment of the present invention.

[0047] FIG. 17b shows the source bias (Vg) at 0 V and the drain-source bias (Vg) at 30 V of an InAs nanocrystal phototransistor under various powers measured at a temporal photoresponsive fixed gate. d This is a drawing showing ).

[0048] FIG. 17c is a diagram showing the transfer curve of a phototransistor according to one embodiment of the present invention.

[0049] Figure 17d is a diagram showing the output curve of a tetrahedral InAs nanocrystalline material measured in various environments.

[0050] The present invention will be described below with reference to the attached drawings. However, the present invention may be implemented in various different forms and is therefore not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0051] Throughout the specification, when it is stated that a part is "connected (connected, in contact, combined)" with another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members interposed between them. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0052] The terms used herein are merely for describing specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0053] Embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0054] The present invention relates to colloidal quantum dots (nanocrystalline) which are semiconductor nanomaterials, and specifically to indium arsenide nanocrystalline particles having a non-spherical tetrahedral shape and a method for manufacturing the same.

[0055] Indium-arsenide nanocrystals are colloidal quantum dot materials belonging to group III-V. Conventional group III-V quantum dots are attracting attention for having a high frequency of stable {111} planes and unstable {100} planes compared to group II-VI materials. In particular, the present invention provides a uniform InAs nanocrystal material that belongs to group III-V quantum dots and has a first exciton absorption of up to approximately 1700 nm, and a method for manufacturing the same.

[0056]

[0057] First, a method for manufacturing an InAs nanocrystalline material according to one embodiment of the present invention will be described.

[0058] FIG. 1 is a flowchart schematically illustrating a method for manufacturing an InAs nanocrystalline material according to one embodiment of the present invention.

[0059] A method for manufacturing an InAs nanocrystalline material according to one embodiment of the present invention, referring to FIG. 1, comprises the steps of: preparing a first solution comprising an indium precursor and a first solvent (S100); preparing a second solution comprising an amino-arsine-based precursor, a reaction relaxant, and a second solvent (S200); and mixing the first solution and the second solution and adding a reducing agent to manufacture an InAs nanocrystalline material (S300).

[0060]

[0061] First, prepare the first solution (S100).

[0062] The first solution above includes an indium precursor and a solvent.

[0063] The above indium precursor is a precursor material containing the element indium, for example, an indium halide material, that is, any type of material combined with a halide in the form of the 1st, 2nd, and 3rd oxidation states of indium, and specifically, for example, may include InCl3, InBr3, and / or InI3, and preferably may include InCl3.

[0064] According to one example, the first solution may be preheated to have a temperature suitable for the reaction. For example, the first solution may be heated to a temperature of 90°C to 140°C under atmospheric pressure or reduced pressure conditions, but is not limited thereto.

[0065] In this regard, the first solution may be heated while mixing the first precursor and the first solvent, but is not limited thereto.

[0066]

[0067] Next, prepare the second solution (S200).

[0068] The second solution above comprises an aminoarsine-based precursor, a reaction relaxant, and a second solvent.

[0069] The above aminoarshin-based precursor is a precursor material containing an arsenide element, and can be represented by the chemical formula As(NR2)3). (Here, R may represent an alkyl group having 1 to 10 carbon atoms.) As a preferred example, the above aminoarshin-based precursor may include tris-dimethylaminoarshin (As(NMe2)3), in which R is a methyl group.

[0070] The first solvent and the second solvent included in the first solution and the second solution above are reactive solvents and correspond to alkyl chain ligand materials having an amine group among the coordinating solvent series, and the amine group can be selected from primary, secondary, or tertiary amine groups.

[0071] That is, as a specific example, the first solvent and the second solvent may each independently comprise, but are not limited to, the group consisting of oleylamine, dodecylamine, hexadecylamine, octadecylamine, octylamine, trioctylamine, and combinations thereof.

[0072] The first and second solvents above may preferably be oleylamine. By using an oleylamine solvent, the dimethylamine group, which is a central As peripheral group of the aminoarsine-based precursor, for example, the tris-dimethylaminoarsine precursor, can be substituted with oleylamine.

[0073] The above reaction relaxant inhibits the reaction between the aminoarsine-based precursor and the solvent, and, for example, lithium bis(trimethylsilyl)amide (lithium bis(trimethylsilyl)amide, hereinafter referred to as LiHMDS additive) may be used.

[0074] The above reaction relaxant serves to mitigate the transamination reaction of the aminoarsine-based precursor and the solvent within the aminoarsine-based precursor solution. The inventors of the present invention noted that rapid nucleation caused by monomer depletion during the process of obtaining InAs nanocrystals having a tetrahedral structure limits the crystal formation process to the formation of a tetrapod structure of the nanocrystal and stops growth into a tetrahedron structure, and sought to solve this problem. Accordingly, in the present invention, by adding a reaction relaxant represented by the above-described LiHMDS to mitigate reactivity, the size of the nanocrystal can be increased, thereby providing InAs nanocrystals having a tetrahedral structure.

[0075] In particular, when the reaction relaxant is LiHMDS, controlling the content of the reaction relaxant and the indium precursor within the range of 0 < [LiHMDS] / [In] < 1 is most suitable for manufacturing tetrahedral nanocrystalline materials. At this time, as the ratio of LiHMDS to indium increases, nanocrystals having a band gap at shorter wavelengths can be synthesized.

[0076] In addition, the step of preparing the first solution and the step of preparing the second solution may be performed by forming the second solution after forming the first solution, forming the first solution after forming the second solution, or forming the first solution and the second solution simultaneously, but are not limited thereto.

[0077]

[0078] Next, the first solution and the second solution are mixed, and a reducing agent is added to produce tetrahedral InAs nanocrystals (S300).

[0079] At this time, the mixing is performed by injecting the second solution into the first solution, and the injection may be a high-temperature injection step performed at 200 to 350 ℃.

[0080] The above reducing agent may include, for example, diisobutyl aluminum hydride (hereinafter referred to as DIBAL-H). DIBAL-H is a hydride-based reducing agent and is a mild reducing agent that does not have excessively strong reactivity among hydride-based reducing agents, and is therefore desirable for obtaining InAs nanocrystalline materials having tetrahedral structures of various sizes.

[0081] The above reducing agent may be included in an amount greater than 0 equiv and less than 6 equiv relative to the concentration of the indium precursor, and preferably at a concentration of 1 equiv.

[0082]

[0083] According to one embodiment of the present invention, the S300 step may include a step of forming a core of the quantum dot by reacting the first solution, the second solution, and a reducing agent, and a step of growing a crystal plane from the core in any crystal direction including {110} and {111} plane directions, but is not limited thereto.

[0084] Quantum dots with a tetrahedral structure can be formed by reacting the first solution, the second solution, and a reducing agent. In this regard, the shape of the quantum dots with a tetrahedral structure can be changed by controlling the reaction temperature in the mixed solution of the first solution, the second solution, and the reducing agent, or by injecting various reducing agents.

[0085]

[0086] Next, an InAs nanocrystal material according to another embodiment of the present invention will be described.

[0087] An InAs nanocrystalline material according to one embodiment of the present invention is a nanocrystalline material having excellent optical and electrical properties in the short-wave infrared region, and is characterized by having a band gap in the range of 1100 to 1847 nm and a tetrahedral structure including a {111} plane as an exposed plane.

[0088] In an embodiment of the present invention, the tetrahedral structure has an exposed {111} plane, and a weak confinement effect is induced by the {111} plane, which is a major technical feature of which the bandgap is extended to the short-wave infrared region compared to a spherical quantum dot of the same volume.

[0089] In particular, each InAs quantum dot in the above nanocrystalline material may have a tetrahedral side length in the range of 5.30 nm to 13.4 nm at a band gap of 1.11 Ev to 0.67 eV, but is not limited thereto.

[0090] The nanocrystalline material described above can be used in a phototransistor device that includes quantum dots as a photoactive layer.

[0091] According to one example, the phototransistor device may comprise: a substrate; a gate electrode stacked on the substrate; a gate insulating layer stacked on the gate electrode; a semiconductor channel layer stacked on the gate insulating layer; a quantum dot layer stacked on the semiconductor channel layer; and a source electrode and a drain electrode spaced apart so that at least a portion of the gate insulating layer and the semiconductor channel layer are in contact with each other with the quantum dot layer in between. However, the structure is not limited to the above-described structure, and any structure comprising a nanocrystalline material according to an embodiment of the present invention as a photoactive layer is included within the technical scope of the present invention.

[0092]

[0093] The present invention will be explained in more detail below through manufacturing examples, comparative examples, and experimental examples. However, the present invention is not limited to the following manufacturing examples and experimental examples.

[0094]

[0095] Example 1: Preparation of InAs nanocrystals (hereinafter, InAs nanocrystals)

[0096] FIG. 3 is a schematic diagram illustrating a method for manufacturing an InAs nanocrystalline material according to an embodiment of the present invention. Hereinafter, the manufacturing process will be described with reference to FIG. 3.

[0097] As the raw material, tris-dimethylaminoarsine (As(NMe2)3) was selected. After a high-temperature injection step in which a lithium bis(trimethylsilyl)amide (LiHMDS) additive was injected into an oleylamine solution containing the As precursor, a reducing agent (diisobutylaluminum hydride, DIBAL-H) ​​was injected. 0.02 equivalents of the LiHMDS additive were added.

[0098] DIBAL-H, which has mild reactivity among hydride-based reducing agents, was selected to obtain tetrahedral InAs nanocrystals of various sizes without forming an alloy with arsenic atoms.

[0099] At this time, it should be noted that rapid nucleation leading to monomer depletion induces the formation of tetrapods and stops growth into tetrahedrons. Therefore, to expand the size range of the final tetrahedral nanocrystals, LiHMDS was added when As(NMe2)3 was mixed with oleylamine to mitigate reactivity.

[0100] Figure 4 is a HAADF-STEM image of a nanocrystalline material prepared according to the method for preparing an InAs nanocrystalline material according to one embodiment of the present invention.

[0101] Referring to Figure 4 above, it can be seen that the nanocrystalline material manufactured according to the above manufacturing method has a tetrahedral shape.

[0102]

[0103] Experimental Example 1: Tetrahedral shape of nanocrystals

[0104] Figure 5 is a diagram showing the results of InAs nanocrystal growth with and without the addition of LiHMDS additive.

[0105] Figure 6 is a graph showing the results of transamination inhibition with and without the addition of LiHMDS additive.

[0106] Referring to FIGS. 5 and 6 above, a small amount (0.02 equivalents) of LiHMDS additive, 1 In the H NMR spectrum, it can be confirmed that the transamination between oleylamine and As(NMe2)3 dimethylamine is inhibited, which can slow down the overall reaction rate and induce an increase in the size of InAs tetrahedral nanocrystals.

[0107] FIG. 7 is a diagram showing the crystal form of a nanocrystal manufactured according to the method for manufacturing InAs nanocrystals according to one embodiment of the present invention.

[0108] FIG. 8 is a diagram showing the absorption spectrum according to the crystal form of nanocrystals manufactured according to the method for manufacturing InAs nanocrystals according to one embodiment of the present invention.

[0109] Based on the screening results, the crystal morphology and corresponding absorption spectra of various InAs nanocrystals were obtained as shown in Figures 7 and 8 above. Tetrahedral nanocrystals smaller than the first exciton absorption size of less than 1100 nm were not observed. As the increase in the surface-to-volume ratio when nanocrystals shrink outweighs the surface energy stabilization effect by ligands, irregularly shaped or significantly truncated nanocrystals are formed in small sizes.

[0110]

[0111] FIG. 9 is a diagram showing the absorption spectrum according to the edge length of an InAs nanocrystal according to one embodiment of the present invention.

[0112] FIG. 10 is a HAADF-STEM image of an InAs nanocrystal according to one embodiment of the present invention.

[0113] Referring to Figures 7 and 9 above, tetrahedral InAs nanocrystals are obtained in an absorption range of 1100–1700 nm (4.4 ± 0.6 to 11.6 ± 1.1 nm) at high monomer concentrations. When the monomer concentration is increased within this size range, larger InAs tetrahedra with well-formed shapes and distinct exciton features are formed as shown in Figure 10 above and collected after purification.

[0114] FIG. 11 is a diagram showing the XRD pattern of InAs nanocrystals according to one embodiment of the present invention.

[0115] FIG. 12 is an experimental / simulated STEM image of an InAs nanocrystal according to one embodiment of the present invention.

[0116] In Figure 12 above, when comparing the simulated scanning transmission electron microscope (STEM) image and the experimental image of the tetrahedral nanocrystal, it can be seen that the change in the nanocrystal projected along the zone axis in the rotated STEM image matches well. This size control was complemented by the X-ray diffraction (XRD) pattern, and as shown in Figure 11 above, the linewidth narrowed as the size of the InAs tetrahedron increased, while maintaining the zinc blend crystal structure across all sizes.

[0117] Furthermore, it was confirmed that the size curve of the tetrahedral InAs nanocrystals exhibits a lower bandgap at the same volume compared to previously reported spherical nanocrystals, which implies that the InAs nanocrystals of the present invention exhibit a weak quantum confinement effect, unlike conventional spherical nanocrystals.

[0118]

[0119] Experimental Example 2: Quantum confinement effect of nanocrystals

[0120] Same volume (32 nm) having band gaps of 1300 nm and 900 nm, respectively 3 Tetrahedral and spherical InAs nanocrystals were prepared.

[0121] FIG. 13 is a mobility curve of tetrahedral InAs nanocrystals (red) and spherical InAs nanocrystals (blue) according to one embodiment of the present invention.

[0122] The tetrahedral InAs QD film is 1.4 × 10⁻⁶ 3 cm 2 The field-effect transistor (FET) electron mobility of / (V·s) was shown, and the spherical film was 1.2 × 10 4 cm 2 / (V·s) was represented.

[0123] The aforementioned observations are consistent with previous results showing that tetrahedral InP NC films exhibit higher FET mobility compared to spherical films. The higher electron mobility of the QD films can be explained by the larger volume fraction of the inorganic core of nanocrystals within the assembled film, which is determined by the volume of the nanocrystals, interparticle distance, arrangement pattern, and the charge density of the QD assembly.

[0124] Figure 14a is a diagram showing the 2D GISAXS pattern for spherical InAs nanocrystals.

[0125] FIG. 14b is a diagram showing a 2D GISAXS pattern for a tetrahedral InAs nanocrystal according to one embodiment of the present invention.

[0126] FIG. 15 is a horizontal cross-sectional view of a tetrahedral InAs nanocrystal and a spherical InAs nanocrystal in the Yoneda region according to one embodiment of the present invention.

[0127] Referring to FIGS. 14a and 14b above, both nanocrystals are randomly assembled within the film, as confirmed by the diffracted incident small-angle X-ray scattering (GISAXS) pattern. The center-to-center distance (d) extracted from the horizontal line cut of FIG. 15 above. q Considering ), the estimated volume fractions for tetrahedral and spherical QD films are 57.2% and 31.2%, respectively.

[0128]

[0129] FIG. 16a is a diagram showing the real part of the dielectric function of a tetrahedral InAs nanocrystalline film and a spherical InAs nanocrystalline film according to one embodiment of the present invention.

[0130] FIG. 16b is a diagram showing the imaginary part of the dielectric function of a tetrahedral InAs nanocrystal film and a spherical InAs nanocrystal film according to one embodiment of the present invention.

[0131] In Figures 16a and 16b above, it can be seen that the tetrahedral QD film exhibits a greater relative permittivity than the spherical film in the range of 400 to 1600 nm.

[0132] FIG. 16c is a transition graph of a tetrahedral InAs nanocrystal film according to one embodiment of the present invention.

[0133] In addition, the reduced amplitude of the fitted imaginary part (ε2) for the tetrahedral InAs QD solid implies weaker confinement characteristics.

[0134]

[0135] Experimental Example 3: Quantum confinement effect of nanocrystals

[0136] FIG. 17a is a drawing showing a phototransistor including InAs nanocrystals according to one embodiment of the present invention.

[0137] In the above experimental example, it was found that incident photons can be efficiently utilized and charge can be efficiently transported within a film assembled with tetrahedral InAs nanocrystals. Accordingly, a short-wave infrared (SWIR) phototransistor was fabricated using tetrahedral InAs nanocrystals with a band gap targeting 1310 nm, as shown in Fig. 17a.

[0138] FIG. 17b shows the source bias (V) at 0 V of an InAs nanocrystal phototransistor under various powers measured at a temporal photoreactive fixed gate. g ) and drain-source bias at 30V (V d This is a drawing showing ).

[0139] FIG. 17c is a diagram showing the transfer curve of a phototransistor according to one embodiment of the present invention.

[0140] Figure 17d is a diagram showing the output curve of a tetrahedral InAs nanocrystalline material measured in various environments.

[0141] Referring to FIGS. 17c and 17d above, the transfer and output characteristics show that the photocurrent increases as the illumination power increases. In particular, the phototransistor of the present invention reached a maximum sensitivity (R) of 20 A / W without much optimization of the device structure and surface treatment.

[0142]

[0143] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0144] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention.

Claims

1. As a nanocrystalline material having excellent optical and electrical properties in the short-wave infrared region, Having a bandgap in the range of 1100 to 1847 nm, Characterized by being a tetrahedral structure including a {111} plane as an exposed plane, InAs nanocrystalline material.

2. In Paragraph 1, The above nanocrystalline material is an InAs nanocrystalline material characterized by having a tetrahedral side length of 5.30 nm to 13.4 nm at a band gap of 1.11 eV to 0.67 eV.

3. A step of preparing a first solution comprising an indium precursor and a first solvent (S100); Step (S200) of preparing a second solution comprising an amino-arsine-based precursor, a reaction relaxant, and a second solvent; and A method for manufacturing an InAs nanocrystalline material, characterized by including the step (S300) of mixing the first solution and the second solution and adding a reducing agent to manufacture an InAs nanocrystalline material.

4. In Paragraph 3, A method for preparing an InAs nanocrystalline material, characterized in that the first solvent is selected from the group consisting of oleylamine, dodecylamine, hexadecylamine, octadecylamine, octylamine, trioctylamine, and combinations thereof.

5. In Paragraph 3, A method for manufacturing an InAs nanocrystalline material, characterized in that the aminoarsine-based precursor has a chemical formula represented as As((NR2)3), and R is an alkyl group having 1 to 10 carbon atoms.

6. In Paragraph 3, A method for manufacturing an InAs nanocrystalline material, characterized in that the above reaction relaxant is lithium bis(trimethylsilyl)amide.

7. In Paragraph 6, A method for manufacturing an InAs nanocrystalline material, characterized in that the lithium bis(trimethylsilyl)amide is added to satisfy the indium element of the indium precursor and the range 0 < [LiHMDS] / [In] < 1.

8. In Paragraph 3, A method for manufacturing an InAs nanocrystalline material, characterized in that the above mixing is performed under temperature conditions of 200 ℃ to 350 ℃.

9. In Paragraph 3, A method for manufacturing an InAs nanocrystalline material, characterized in that the reducing agent comprises diisobutyl aluminum hydride.

10. In Paragraph 9, A method for manufacturing an InAs nanocrystalline material, characterized in that the reducing agent is added in an amount of 0 to 6 equiv relative to the concentration of the indium precursor.

11. An InAs nanocrystalline material manufactured by the manufacturing method of paragraph 3.

12. A phototransistor device comprising the InAs nanocrystalline material of claim 1.

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