Low-loss heterostructure semiconductor material based on antimony telluride compounds and preparation and use thereof

Abstract

The application discloses a low-loss hetero-junction semiconductor material based on antimony tellurium compound and preparation and application thereof, and relates to the following steps: irradiating a stable hexagonal phase Sb2Te3 crystal sample with a high-energy particle beam, so that the bulk phase inside the sample is converted into a cubic phase, and the hexagonal phase structure of a region from the surface to the inside of the sample to 10 nm is kept unchanged; the stable hexagonal phase Sb2Te3 bulk phase inside structure is converted into a cubic phase; and the Anderson insulating property of the bulk phase inside makes the charges be subjected to Anderson localization, and the charges are converted into an insulating state. The application converts the bulk phase inside of the topological insulator hexagonal phase Sb2Te3 crystal into a cubic phase by irradiating the bulk phase inside with a high-energy particle beam, forms charge Anderson localization in the bulk phase, converts the bulk phase into an insulating state, keeps the hexagonal phase topological insulating property in the range from the surface to the inside of the sample to 10 nm, can inhibit the electric transport performance of the bulk phase inside, drives the current to pass through only the surface, thereby reducing the transport loss, and realizes super-low power consumption transport.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor material preparation, in particular to a low-loss heterostructure semiconductor material based on antimony tellurium compounds and preparation and application thereof. BACKGROUND

[0002] Topological insulator is a special insulator, whose bulk electronic band structure is similar to that of traditional insulator, showing insulating property. The surface state is protected by structural inversion symmetry and affected by electron spin-orbit coupling, and is not easily destroyed by defects and non-magnetic impurities in the system, showing metallic property. When electrons transport in the surface state, spin and momentum are locked, which can achieve ultra-low loss, so topological insulator has broad application prospects in low-loss electromagnetic transport systems, storage systems and fault-tolerant quantum computing systems.

[0003] Since the bulk conductive ability of topological insulator is difficult to be completely suppressed, the ultra-low loss surface electrical transport still faces challenges. For example, stable hexagonal phase Sb2Te3 crystal is a typical strong topological insulator material, whose bulk phase is in insulating state and the surface shows metallic state, and the surface state is protected by symmetry, which can avoid the influence of non-magnetic impurities and disorder. However, due to the existence of spontaneous doping behavior in the bulk phase of hexagonal phase Sb2Te3, a large number of hole carriers (10 19 -10 20 cm -3 ) are generated, making the bulk phase show metallic property, which affects the low-loss electrical transport behavior of the sample surface. Therefore, to realize low-loss electrical transport by using the topological insulating property of stable hexagonal phase Sb2Te3 crystal, it is necessary to ensure that the bulk phase is insulating.

[0004] Previous studies have shown that metastable cubic phase Sb2Te3 crystal has a large number of vacancies in its structure, accounting for about 1 / 6 of the entire lattice. These large number of randomly distributed vacancies cause the cubic phase Sb2Te3 crystal to have the property of Anderson insulator, i.e. the electrons in the system are localized near the vacancies, greatly reducing the carrier mobility and showing insulating characteristics. In order to realize the ultra-low loss electrical transport of Sb2Te3 topological insulator, it is urgent to develop a method to convert the bulk phase of hexagonal phase Sb2Te3 crystal into cubic phase while maintaining the topological insulating property of its surface. SUMMARY

[0005] In order to overcome the above-mentioned deficiencies of the prior art, the purpose of the present application is to provide a low-loss hetero-junction semiconductor material based on antimony tellurium compound and its preparation and application, which uses high-energy particle beam irradiation to convert the bulk phase of hexagonal phase Sb2Te3 crystal into cubic phase, forms charge Anderson localization in the bulk phase, converts the bulk phase into insulating state, and maintains the hexagonal phase topological insulating properties within the range of 10 nm from the surface to the interior, so as to suppress the electrical transport performance in the bulk phase, drive the current only through the surface, thereby reducing the transport loss and realizing ultra-low power transport.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is:

[0007] A low-loss hetero-junction semiconductor material based on antimony tellurium compound is Sb2Te3 crystal, characterized in that the crystal structure of the region from the surface to the interior of 10 nm of the crystal is hexagonal phase structure, the region within 10 nm from the interior is bulk phase, and the crystal structure of the bulk phase is cubic phase structure.

[0008] The hexagonal phase structure and the cubic phase structure are directly connected and constitute a hetero-junction structure.

[0009] The bulk phase of the stable hexagonal phase Sb2Te3 crystal sample is irradiated by a high-energy particle beam, so that the bulk phase is converted into cubic phase, and the region from the surface to the interior of 10 nm of the sample remains unchanged as hexagonal phase structure, the Anderson insulating property of the bulk phase causes Anderson localization of charges, and the bulk phase is converted into insulating state.

[0010] The hexagonal phase structure of the region from the surface to the interior of 10 nm exhibits topological insulator properties, the cubic phase structure of the bulk phase exhibits Anderson insulator properties, and the two phase structures are directly connected and constitute a hetero-junction structure.

[0011] The high-energy particle beam includes but is not limited to high-energy electron beam, pulsed laser beam and argon ion beam.

[0012] The acceleration voltage of the high-energy electron beam is 500-1000KeV, and the irradiation intensity is not less than 1x10 24 e m -2 s -1 .

[0013] The laser wavelength range of the pulsed laser beam is 532-785nm, the power is not less than 5mW, and the pulse width is not more than 10s.

[0014] The acceleration voltage of the argon ion beam is not less than 30KeV, and the irradiation intensity is not less than 1x10 10 ions cm -2 .

[0015] The antimony tellurium compound low-loss heterostructure semiconductor material can be used in future information storage and spin electronic devices for quantum computing, frequency multiplier, digital storage, optoelectronic devices, and high-speed lossless electrical signal transmission and chip interconnection structure.

[0016] The surface state of the antimony tellurium compound low-loss heterostructure semiconductor material prepared by the application has extremely high carrier mobility, and the carrier transmission process in the surface state is close to zero loss, and the electronic device processed based on the material can be used to replace the traditional silicon-based device, and the speed can be improved, the energy consumption can be saved, and the photoelectric detection range of the device can be improved under the same feature size. Meanwhile, the material has topological superconducting characteristics, and can replace metal conductors in chip interconnection structure to realize ultra-low loss.

[0017] The application has the following beneficial effects:

[0018] The application utilizes high-energy particle beam irradiation to convert the hexagonal phase Sb2Te3 crystal body phase inside the topological insulator into a cubic phase, form charge Anderson localization in the body phase, convert the body phase into an insulating state, and keep the hexagonal phase topological insulating properties within a range of 10nm from the surface to the inside, so that the electrical transport performance of the body phase inside can be inhibited, and the current is forced to pass through the surface only, thereby reducing the transport loss and realizing ultra-low power consumption transport. The hexagonal phase Sb2Te3 crystal can guarantee its topological insulating properties when the thickness is not less than 4nm, and the metallicity of the body phase inside will affect the topological insulating property when it is too thick.

[0019] The application selects a range of 10nm from the surface to the inside of the sample, which guarantees the topological insulating property and inhibits the effect of metallicity, so that the topological insulating property of the material can be utilized to the maximum extent. In addition, the cubic phase formed by irradiation is usually polycrystalline, and the existence of grain boundaries further leads to the scattering of electron transmission and improves the insulating property of the body phase. Therefore, the electrical transport behavior only occurs on the surface of the sample body phase, and the current cannot flow through the body phase inside, which is beneficial to realize ultra-low loss electrical transport.

[0020] The preparation method of the heterostructure semiconductor material provided by the application directly utilizes the carrier localization induced by the structural disorder inside the material, so that no additional gate voltage is needed to neutralize the high-concentration carriers caused by spontaneous doping, the device processing process difficulty can be effectively reduced, and the application is compatible with the traditional semiconductor processing process.

[0021] The Sb2Te3 heterostructure prepared by the application has a relatively flat interface formed by the two crystal phases of Sb2Te3, and there is no obvious structural gap and lattice mismatch near the interface, which is beneficial to prevent the influence of interface reconstruction, interface shedding or stress on the transport characteristics, stability and service life of the device. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1Fig. 1 is a schematic diagram of a hexagonal phase Sb2Te3 crystal sample and the corresponding atomic structure of the hexagonal phase.

[0023] Figure 2 Fig. 2 is a schematic diagram of the hexagonal phase Sb2Te3 crystal sample irradiated by a high-energy particle beam and the corresponding atomic structure of the cubic phase.

[0024] Figure 3 Fig. 3 is a schematic diagram of a low-loss heterostructure semiconductor sample and the corresponding electrical transport behavior of the sample.

[0025] Figure 4 Fig. 4 is a high-resolution image of the hexagonal phase Sb2Te3 crystal sample before irradiation by a high-energy particle beam.

[0026] Figure 5 Fig. 5 is a high-resolution image of the cubic phase Sb2Te3 crystal formed in the bulk phase after irradiation by a high-energy particle beam. DETAILED DESCRIPTION

[0027] The application will be further described in detail below with reference to the accompanying drawings.

[0028] Figure 1 Fig. 1 is a schematic diagram of a hexagonal phase Sb2Te3 crystal sample and the corresponding atomic structure of the hexagonal phase. The hexagonal phase structure of Sb2Te3 is separated by a vacancy layer into a layered structure, and the Sb and Te atoms in the layer block are alternately stacked to form a 5-layer structure of -Te-Sb-Te-Sb-Te-. The hexagonal phase Sb2Te3 crystal exhibits topological insulator properties due to strong electron spin-orbit coupling.

[0029] Figure 2 Fig. 2 is a schematic diagram of the hexagonal phase Sb2Te3 crystal sample irradiated by a high-energy particle beam and the corresponding atomic structure of the cubic phase. Irradiation of the crystal sample by a high-energy particle beam can cause it to transform into a cubic phase structure. The atomic structure diagram shows that there is no vacancy layer in the cubic phase, and vacancies are randomly distributed throughout the system, accounting for about 1 / 6 of the entire lattice. These large numbers of randomly distributed vacancies result in the cubic phase Sb2Te3 crystal having the properties of an Anderson insulator.

[0030] Figure 3It is a schematic diagram of a low-loss hetero-homo junction semiconductor sample and its electrical transport. The 10nm region from the surface to the interior of the sample is a hexagonal phase structure, which is a topological insulating region; the interior of the bulk phase is a cubic phase structure, which is an Anderson insulating region. The hexagonal phase Sb2Te3 crystal can ensure its topological insulating property when the thickness is not less than 4nm, and the bulk phase interior metallicity will affect the topological insulating property when it is too thick. Therefore, the present application selects the range from the surface to the interior of the sample within 10nm, which not only ensures the topological insulating property, but also suppresses the effect of metallicity, so that the topological insulating property of the material can be utilized to the maximum extent. Due to the similarity of atomic arrangement and crystal density between the cubic phase and the hexagonal phase, compared with the heterostructure, the hetero-homo interface formed by the two crystal phases of Sb2Te3 is relatively flat, and there is no obvious structure gap and lattice mismatch near the interface, which is beneficial to prevent interface reconstruction, interface shedding or stress, and improve the device transport characteristics, stability and service life, etc. When an electric field is applied to the surface of the sample, due to the large insulating property of the bulk phase Anderson insulating region, the carriers will mainly transport in the topological insulating region on the surface of the sample, avoiding the interference of the bulk phase interior with the surface electrical transport behavior, and realizing ultra-low loss electrical transport.

[0031] Figure 4 It is a high-resolution image of the hexagonal phase Sb2Te3 crystal sample before irradiation by a high-energy particle beam. The high-resolution image shows that each five layers of atoms constitute a layer block, and the dark area between the layer blocks corresponds to a vacancy layer. The crystal orientation is marked in the Fourier transform spectrum as The orientation shows the typical layered structure of the hexagonal phase Sb2Te3.

[0032] Figure 5 It is a high-resolution image of the cubic phase Sb2Te3 crystal formed in the interior of the sample after irradiation by a high-energy particle beam. The grain in the high-resolution image is the most typical crystal face orientation

[001] of the cubic phase structure, and the (020) and The interplanar spacing of the crystal faces is 0.305nm, and the interplanar angle is about 90°. The spots corresponding to the (020) and (020) crystal faces are marked in the FFT spectrum.

[0033] The present application will be further described below with specific examples.

[0034] Example 1

[0035] This example takes the preparation of a low-loss hetero-homo junction semiconductor by irradiating a stable hexagonal phase Sb2Te3 crystal sample with a high-energy electron beam as an example, and the specific process is as follows:

[0036] The stable hexagonal phase Sb2Te3 crystal sample is irradiated with a high-energy electron beam, so that the bulk phase interior is converted into a cubic phase while the region from the surface to the interior within 10nm remains unchanged. The acceleration voltage of the high-energy electron beam is 700KeV, the irradiation intensity is 5x10​25 e m -2 s -1 The irradiation position is adjusted so that the surface to the interior 10 nm region of the hexagonal phase is not affected by the high-energy electron beam. The Sb2Te3 crystal sample irradiated by the high-energy electron beam has the surface hexagonal phase part exhibiting topological insulator properties, and the cubic phase in the bulk interior exhibiting Anderson insulator properties, and the two phase structures are directly connected and constitute a heterostructure, obtaining a Sb2Te3 low-loss heterostructure semiconductor material. The Sb2Te3 low-loss heterostructure semiconductor material is integrated in an electronic storage device, which can improve the response rate of the device and reduce the device loss.

[0037] Embodiment 2

[0038] This embodiment takes the preparation of a low-loss heterostructure semiconductor by irradiating a stable hexagonal phase Sb2Te3 crystal sample with a pulsed laser beam as an example, and the specific process is as follows:

[0039] A stable hexagonal phase Sb2Te3 crystal sample is irradiated with a pulsed laser beam, so that the bulk interior is converted into a cubic phase while keeping the surface to the interior 10 nm region unchanged. The pulsed laser beam has a laser wavelength range of 650 nm, a power of 150 mW, and a pulse width of 1 s. The irradiation position is adjusted so that the surface to the interior 10 nm region of the hexagonal phase is not affected by the pulsed laser beam. The Sb2Te3 crystal sample irradiated by the pulsed laser beam has the surface hexagonal phase part exhibiting topological insulator properties, and the cubic phase in the bulk interior exhibiting Anderson insulator properties, and the two phase structures are directly connected and constitute a heterostructure, obtaining a Sb2Te3 low-loss heterostructure semiconductor material. The Sb2Te3 low-loss heterostructure semiconductor material is integrated in an electrical signal transmission and chip interconnection structure, which can achieve high-speed lossless signal transmission.

[0040] Embodiment 3

[0041] This embodiment takes the preparation of a low-loss heterostructure semiconductor by irradiating a stable hexagonal phase Sb2Te3 crystal sample with an argon ion beam as an example, and the specific process is as follows:

[0042] A stable hexagonal phase Sb2Te3 crystal sample is irradiated with an argon ion beam, so that the bulk interior is converted into a cubic phase while keeping the surface to the interior 10 nm region unchanged. The argon ion beam has an acceleration voltage of 200 KeV and an irradiation intensity of 5×10 15 ions cm -2The irradiation position is adjusted so that the surface hexagonal phase and the 10 nm region inside the surface are not affected by the argon ion beam. The Sb2Te3 crystal sample irradiated by the argon ion beam has a surface hexagonal phase part exhibiting topological insulator properties and a cubic phase part in the bulk phase inside exhibiting Anderson insulator properties, and the two phase structures are directly connected and constitute a heterostructure, thereby obtaining a Sb2Te3 low-loss heterostructure semiconductor material. The Sb2Te3 low-loss heterostructure semiconductor material can be integrated in a quantum computing spin electronic device, so that the response rate of the device is improved and the device loss is reduced.

Claims

1. A method for preparing a low-loss heterostructure semiconductor material based on antimony telluride compounds, characterized in that, By using high-energy particle beam to irradiate the bulk phase of the stable hexagonal phase Sb2Te3 crystal sample, the bulk phase is transformed into cubic phase, while the surface to the interior 10nm region remains unchanged, the bulk phase interior Anderson insulating property makes the charge Anderson localization, and the bulk phase interior is transformed into insulating state; The hexagonal phase structure of the surface to the interior 10nm region presents topological insulator property, the cubic phase structure of the bulk phase interior presents Anderson insulator property, and the two phase structures are directly connected and constitute a heterostructure; The high-energy particle beam is selected from high-energy electron beam, pulsed laser beam and argon ion beam; The acceleration voltage of the high-energy electron beam is 500-1000KeV, and the irradiation intensity is not less than 1×10 24 e m -2 s -1 ; The laser wavelength of the pulsed laser beam ranges from 532nm to 785nm, the power is not less than 5mW, and the pulse width is not more than 10s; The acceleration voltage of the argon ion beam is not less than 30KeV, and the irradiation intensity is not less than 1x10 10 ions cm -2 .

2. Use of the low-loss isobstructural semiconducting material based on antimony telluride compounds obtained by the method according to claim 1, characterized by the fact that it is used in the production of photovoltaic cells, photodetectors, infrared detectors, thermoelectric devices, and in the production of nanowires, nanotubes, quantum dots, and other nanostructures. The antimony tellurium compound low-loss heterostructure semiconductor material can be used for future information storage and quantum computing spin electronic devices, frequency multiplier, digital storage, optoelectronic devices, and high-speed lossless electrical signal transmission and chip interconnection structure.

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