Quickly switchable dirac source device

Abstract

The application discloses a Dirac source device capable of being rapidly switched, which comprises a first electrode, a second electrode and a channel region, the first electrode comprises a source material layer, the source material has a Dirac cone type energy band structure, the second electrode comprises a two-dimensional material layer, a first end of the channel layer is connected with the source material layer through a covalent bond to form a planar heterojunction, and a second end of the channel layer is connected with the two-dimensional material layer, the Dirac source device provided by the application has a steep sub-threshold swing and has a rapid switching function, the source material and the channel layer material are combined through a covalent bond to form a planar heterojunction, the covalent bond makes the atoms have a strong coupling force, which is helpful to reduce the interface contact resistance of the source material and the channel layer material and improve the current passing through the heterojunction.

Description

Technical Field

[0001] This invention relates to the field of nanoelectronics, and in particular to a Dirac source device that can be switched quickly. Background Technology

[0002] In traditional metal-oxide-semiconductor field-effect transistors (MOSFETs), the hot carriers injected from the source follow an exponentially decaying Boltzmann statistical distribution, resulting in an exponential dependence of the device's operating current and subthreshold swing (SS) on temperature. The theoretically calculated limit for the SS value is 60 mV / decade. Currently, two types of devices with steep subthreshold swings—tunneling transistors (TFETs) and non-capacitive transistors (NC-FETs)—have both surpassed the 60 mV / decade SS limit, becoming promising new devices to replace traditional MOSFETs. However, the tunneling transistor operates by utilizing inter-band tunneling between the source and channel regions, resulting in a relatively small on-state current, typically less than 10 μA / μm. Furthermore, NC-FETs exhibit significant hysteresis, limiting their practical applications. Summary of the Invention

[0003] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0004] With the development of integrated circuit technology, the density of electronic devices such as transistors in chips is increasing, and the device size is decreasing. Two-dimensional materials, with their atomic-level thickness and excellent physical properties, have broad prospects for applications in low-dimensional sub-10-nanometer electronic devices. Combining different two-dimensional materials to form heterojunctions can combine the excellent properties of different two-dimensional materials, enabling the design and manufacture of high-performance devices.

[0005] Dirac source devices are novel devices with ultra-steep subthreshold swings. Their source materials are typically graphene or other graphene-like materials with a Dirac cone band structure. Due to the linear dispersion of graphene near the Dirac point, its hot electron distribution exhibits super-exponential decay. During the device's transition from on to off, the number of hot electrons injected from the source decreases rapidly with increasing potential barrier, resulting in a rapid decrease in thermionic current and thus rapid turn-off. Therefore, Dirac source devices utilize the carrier concentration distribution characteristics caused by the linear dispersion of graphene near the Dirac point to achieve a steep subthreshold swing.

[0006] Related technologies have been used in experiments to fabricate Dirac source devices using van der Waals heterojunctions composed of graphene and two-dimensional materials (such as molybdenum disulfide), achieving steep subthreshold swings below 60 mV / decade. However, the inventors discovered that because there are no dangling bonds on the surface of two-dimensional materials, the graphene and molybdenum disulfide are bonded by weak van der Waals interactions, and no chemical bonds are formed at the interface. This results in very weak coupling between graphene and the two-dimensional material. The tunneling of charge carriers from graphene to the two-dimensional material requires passing through the van der Waals barrier at the interface, resulting in a large interfacial contact resistance and a small on-state current. Currently, the on-state current of Dirac source devices fabricated using graphene / molybdenum disulfide van der Waals heterojunctions can only reach the order of 10 μA / μm, affecting the practical application value of Dirac source devices.

[0007] Furthermore, the inventors discovered that the van der Waals heterojunction formed between graphene and molybdenum disulfide is a vertical heterojunction, meaning the two elements are formed perpendicularly. Structurally, graphene and molybdenum disulfide can also form planar heterojunctions. Based on this, the inventors proposed the following: In a planar heterojunction formed between graphene and molybdenum disulfide, the interface atoms are bonded by covalent bonds. These covalent bonds result in strong coupling between atoms, which may reduce the interfacial contact resistance and increase the current flowing through the heterojunction.

[0008] Based on the above understanding of the technical problems in related technologies and with the aim of solving at least one of the aforementioned technical problems, the inventor conceived and conducted relevant verifications, and proposed this invention. An embodiment of this invention provides a Dirac source device capable of rapid switching.

[0009] The rapidly switchable Dirac source device of this invention includes: a first electrode, the first electrode including a source material layer, the source material having a Dirac cone band structure; a second electrode, the second electrode including a two-dimensional material layer; and a channel region located between the first electrode and the second electrode in a first extending direction, the first extending direction being the length direction or width direction of the Dirac source device, the channel region including a channel layer, the channel layer having a first end and a second end opposite to each other in the first extending direction, the first end of the channel layer being covalently connected to the source material layer to form a planar heterojunction, and the second end of the channel layer being connected to the two-dimensional material layer.

[0010] The Dirac source device provided in this invention has a steep subthreshold swing and fast switching capability. Along the length or width of the Dirac source device, the source material and the channel layer material are covalently bonded to form a planar heterojunction. These covalent bonds provide strong coupling between atoms, which helps reduce the interfacial contact resistance between the source material and the channel layer material, thereby increasing the current flowing through the heterojunction, i.e., enhancing the on-state current.

[0011] In some embodiments, the source material is graphene or graphene-like material.

[0012] In some embodiments, the source material layer is a single-layer graphene layer or a single-layer graphene-like layer.

[0013] In some embodiments, the two-dimensional material layer is a molybdenum disulfide layer; and / or, the channel layer is a molybdenum disulfide channel layer.

[0014] In some embodiments, the first electrode includes a source material extension region extending from the source material layer and used to connect to a first end of the channel layer; and / or, the second electrode includes a two-dimensional material extension region extending from the two-dimensional material layer and connected to a second end of the channel layer.

[0015] In some embodiments, the source material layer is a single-layer graphene layer, the channel layer is a molybdenum disulfide channel layer, the molybdenum disulfide channel layer includes two sulfur atom layers and one molybdenum atom layer, the molybdenum atom layer is sandwiched between the two sulfur atom layers to form a sandwich structure, and the sulfur atom layer is bonded to the graphene layer to form a graphene-molybdenum disulfide planar heterojunction.

[0016] In some embodiments, the source material layer is a single-layer graphene layer, the channel layer is a molybdenum disulfide channel layer, the two-dimensional material layer is a molybdenum disulfide layer, the graphene layer is p-type doped, and the carrier concentration ranges from 3 × 10⁻⁶. 19 e / cm 3 -7×10 19 e / cm 3 The molybdenum disulfide layer is n-type doped with a carrier concentration of 3 × 10⁻⁶. 20 e / cm 3 .

[0017] In some embodiments, the carrier concentration of the graphene layer is 5 × 10⁻⁶. 19 e / cm 3 .

[0018] In some embodiments, the channel length of the Dirac source device is in the sub-ten nanometer range.

[0019] In some embodiments, stress is applied to the source material layer. Attached Figure Description

[0020] Figure 1 This is a top view of the Dirac source device that can be quickly switched according to an embodiment of the present invention.

[0021] Figure 2 This is a side view of the Dirac source device that can be quickly switched according to an embodiment of the present invention.

[0022] Figure 3 This is a diagram showing the density of states, carrier concentration distribution, and molybdenum disulfide conduction band bottom position in the channel region of the graphene source device in the subthreshold region of the Dirac source device according to an embodiment of the present invention.

[0023] Figure label:

[0024] 1-First electrode; 2-Channel region; 201-Silicon dioxide dielectric layer; 202-Metal gate; 203-Graphene extension region; 204-Molybdenum disulfide channel layer; 205-Molybdenum disulfide extension region; 2041-Sulfur atom layer; 2042-Molybdenum atom layer; 3-Second electrode. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0026] The following is based on Figure 1 and Figure 2 The basic structure of the rapidly switchable Dirac source device provided in this embodiment of the invention is described. The Dirac source device includes a first electrode 1, a channel region 2, and a second electrode 3.

[0027] The first electrode 1 includes a source material layer. The source material has a Dirac cone band structure. The source material with the Dirac cone band structure (such as graphene or graphene-like material) has a linear dispersion relation near the Dirac point, thereby enabling the Dirac source device to have an ultra-steep subthreshold swing to achieve a fast turn-off function.

[0028] The second electrode 3 includes a two-dimensional material layer. The channel region 2 is located between the first electrode 1 and the second electrode 3 in a first extending direction, which is the length or width direction of the Dirac source device. This is the structural basis for the planar heterojunction of the Dirac source device. The channel region 2 includes a channel layer, which has a first end and a second end opposite to each other in the first extending direction. The first end of the channel layer is covalently connected to the source material layer of the first electrode 1 to form a planar heterojunction of source material / channel layer material, and the second end of the channel layer is connected to the two-dimensional material layer of the second electrode 3.

[0029] The Dirac source device provided in this invention has a steep subthreshold swing and fast switching capability. Along the length or width of the Dirac source device, the source material and the channel layer material are covalently bonded to form a planar heterojunction. These covalent bonds provide strong coupling between atoms, which helps reduce the interfacial contact resistance between the source material and the channel layer material, thereby increasing the current flowing through the heterojunction, i.e., enhancing the on-state current.

[0030] Optionally, the source material is graphene or a graphene-like material with a Dirac cone band structure. Graphene-like materials refer to a general term for materials with a two-dimensional single-layer or few-layer structure, whose structure is similar to that of graphene.

[0031] Preferably, the source material is graphene.

[0032] Optionally, the source material layer of the first electrode 1 is a single-layer graphene layer or a single-layer graphene-like layer.

[0033] Preferably, the source material layer is a single-layer graphene layer.

[0034] Optionally, the two-dimensional material layer in the second electrode 3 is a molybdenum disulfide layer.

[0035] Alternatively, the channel layer in channel region 2 is a molybdenum disulfide channel layer. The difference is that the molybdenum disulfide layer of the second electrode 3 is a doped layer, while the molybdenum disulfide channel layer in channel region 2 is an undoped layer.

[0036] In some embodiments, the first electrode 1 includes a source material extension region extending from the source material layer of the first electrode 1 and connected to a first end of the channel layer of the channel region 2, wherein the material of the source material extension region and the material of the channel layer are covalently bonded together. The second electrode 3 includes a two-dimensional material extension region extending from a two-dimensional material layer and connected to a second end of the channel layer.

[0037] The following is based on Figures 1-2 The following describes a Dirac source device in a specific embodiment of the present invention.

[0038] like Figure 1As shown, the Dirac source device includes a first electrode 1, a channel region 2, and a second electrode 3. The first electrode 1, the channel region 2, and the second electrode 3 are arranged sequentially in a first preset direction, which in this embodiment is the length direction of the Dirac source device.

[0039] The first electrode 1 includes a source material layer, which is a single-layer graphene layer, meaning the source material is graphene and the graphene has a single-layer structure. The graphene layer extends towards the first end of the channel region 2 to form a source material extension region, namely, the graphene extension region 203.

[0040] The channel layer of channel region 2 is a molybdenum disulfide channel layer 204, which includes two sulfur atom layers 2041 and one molybdenum atom layer 2042. The molybdenum atom layer 2042 forms a sandwich structure between the two sulfur atom layers 2041. The sulfur atom layer 2041 bonds with the graphene extension region 203 to form a graphene / molybdenum disulfide planar heterojunction. The sulfur atom layer 2041 and the graphene extension region 203 are bonded by covalent bonds. Since the coupling strength of covalent bonds is greatly enhanced compared with the weak van der Waals interaction force, the contact resistance of the atomic interface between the two is greatly reduced. Therefore, the Dirac source device provided in this embodiment of the invention can effectively improve its on-state current while ensuring a steep subthreshold swing, and can even reach or exceed the on-state current exhibited by transistor devices in related technologies.

[0041] The second electrode 3 includes a molybdenum disulfide layer, meaning the two-dimensional material is molybdenum disulfide. The molybdenum disulfide layer extends towards the second end of the channel region 2, forming a two-dimensional material extension region, namely, the molybdenum disulfide extension region 205. In this embodiment, the molybdenum disulfide extension region 205 is connected to the molybdenum disulfide channel layer 204 of the channel region 2, and both are single-layer molybdenum disulfide layers. The difference is that the molybdenum disulfide extension region 205 and the molybdenum disulfide layer are both doped layers, while the molybdenum disulfide channel layer 204 is an undoped layer.

[0042] like Figure 2 As shown, the channel region 2 also includes two silicon dioxide dielectric layers 201 and two metal gates 202. The molybdenum disulfide channel layer 204 is sandwiched between the two silicon dioxide dielectric layers 201, and the two metal gates 202 sandwich the molybdenum disulfide channel layer 204 and the silicon dioxide dielectric layer 201.

[0043] The channel length of the Dirac source device provided in this embodiment of the invention is in the sub-ten nanometer range. For example, the length of channel region 2 is 8.5 nanometers. According to the international semiconductor technology roadmap, when the length of channel region 2 is 8.5 nanometers, the bias voltage between the first electrode 1 and the second electrode 3 is fixed at 0.69V, and the device switching gate voltage range is between -0.4V and 1.4V.

[0044] To illustrate the effect of planar heterojunctions on improving on-state current, the inventors performed theoretical calculations and compared the performance of a Dirac source device fabricated from a graphene / molybdenum disulfide van der Waals heterojunction with the same channel length of 8.5 nm with that of the planar heterojunction fabricated from graphene / molybdenum disulfide provided in the above embodiments. The results showed that the on-state current of the Dirac source device fabricated from the van der Waals heterostructure could only reach 10. -1 The current is on the order of μA / μm. Furthermore, calculations on the Dirac source device constructed from a graphene / molybdenum disulfide planar heterostructure proposed in this embodiment show an on-state current reaching 10... 2 The device is on the order of μA / μm and has a steep subthreshold swing below 60mV / decade.

[0045] In summary, the on-state current of the graphene / molybdenum disulfide planar heterojunction Dirac source device proposed in this invention is increased by more than two orders of magnitude compared to the van der Waals heterojunction Dirac source device with the same channel length, and is also one order of magnitude higher than the on-state current of the previously experimentally fabricated graphene / molybdenum disulfide van der Waals heterojunction Dirac source device with a larger size. Therefore, the Dirac source device provided in this invention forms a planar heterojunction between graphene and molybdenum disulfide, effectively overcoming the drawback of high interfacial contact resistance in related technologies, and is of great significance for the design and fabrication of low-resistance planar heterojunction devices.

[0046] Furthermore, due to the different lattice constants between different materials, lattice mismatch may occur when two different materials form a heterojunction, resulting in stress in the source and channel regions near the interface. Therefore, during device fabrication, stress is applied to the materials through external stretching or compression to overcome the lattice mismatch problem when the two materials form a heterojunction. The inventors' research found that in this embodiment, when stress is applied to the graphene layer, the Dirac source device exhibits a larger on-state current. Therefore, preferably, the Dirac source device provided in this embodiment applies stress to the graphene layer.

[0047] It should be noted that in this embodiment, applying stress to graphene resulted in a better on-state current. However, in other embodiments, using other source and channel materials to form a heterojunction, it is possible to apply stress to the channel material to obtain a better on-state current. This depends on the band arrangement of the two materials forming the heterojunction. The material to which the stress is applied has a smaller interface barrier, and thus a larger on-state current may be obtained.

[0048] The source carrier concentration can be expressed as n(E) = D(E) × f(E). Here, f(E) is the Boltzmann distribution, which has an exponential relationship with energy; D(E) is the source polar state density. Since graphene has a linear dispersion near the Dirac point, the source polar state density D(E) has a linear relationship with energy near the Dirac point. Multiplying D(E) by f(E) may cause the carrier distribution to change exponentially.

[0049] Dirac source devices require specific band alignment between the source and channel regions. Specifically, the channel barrier should vary along the linear band structure between the source Dirac point and the source Fermi level. The super-exponential distribution in this region causes a rapid change in carrier numbers, resulting in a rapid change in current. Specifically, as the device transitions from the on state to the off state, the carrier concentration injected from the source decreases super-exponentially with increasing barrier strength, causing a rapid decrease in device current and achieving rapid turn-off. Similarly, as the device transitions from the off state to the on state, the carrier concentration injected from the source increases super-exponentially with decreasing barrier strength, causing a rapid increase in device current and enabling rapid on-state operation. When the device is in the on state, the interface band alignment is the same as in conventional transistor devices and does not affect the on-state current. In this embodiment of the invention, the band alignment requirements between the graphene source and the molybdenum disulfide channel region can be achieved by controlling the doping type and concentration.

[0050] In the Dirac source device provided in this embodiment of the invention, considering that the experimentally prepared molybdenum disulfide is usually n-type, the molybdenum disulfide drain (the molybdenum dioxide layer of the second electrode 3) is n-type doped. To meet the bandgap alignment requirements, the graphene source (the graphene layer of the first electrode 1) needs to be p-type doped. Conversely, when the device drain is p-type doped, the graphene source needs to be n-type doped.

[0051] In this case, the carrier concentration of the n-type molybdenum disulfide drain is selected to be 3 × 10⁻⁶. 20 e / cm 3 The carrier concentration of the p-type graphene source was selected as 1×10⁻⁶. 20 e / cm 3 5×10 19 e / cm 3 and 1×10 19 e / cm 3 The performance of Dirac source devices was compared. Under three different carrier concentrations in the graphene source, the Dirac source device exhibited the most rapid current change and the lowest SS value when in the subthreshold region (corresponding to a gate voltage of 0-0.2V in this case). That is, the subthreshold region is the area where the current of the Dirac source device rapidly decreases (increases) from the on state to the off state (or vice versa).

[0052] Figure 3The source carrier concentration distribution of graphene source at three different carrier concentrations when the device is in the subthreshold region is presented. The differences in subthreshold swing performance in these three cases are explained below.

[0053] When the source carrier concentration of graphene is 1×10 20 e / cm 3 At that time, the graphene source electrode doping concentration was relatively high, and the graphene Dirac point was much higher than the Fermi level of the system. For example... Figure 3 As shown in (a) and (b), during the transition from a gate voltage of 0 to 0.2V (corresponding to the device switching from off to on), the source carrier concentration decreases from a very small value to a very small value. This means the source carrier concentration changes relatively slowly in the subthreshold region, resulting in a smaller current change and a larger SS value within this gate voltage range. Furthermore, the source carrier concentration is also lower from the off state to the on state, thus the on-state current of the device is also smaller.

[0054] When the source carrier concentration of graphene is 1×10 19 At a doping concentration of e / cm, the graphene source electrode has a relatively low doping concentration, and the graphene Dirac point is slightly higher than the Fermi level of the system. For example... Figure 3 As shown in (e) and (f), during the change from 0 gate voltage to 0.2V gate voltage (corresponding to the device switching from off to on), the source carrier concentration increases significantly. Similar to the case with higher doping concentrations, the source carrier concentration changes relatively slowly in the subthreshold region, resulting in a larger SS value for the device. Therefore, it is necessary to select an appropriate graphene source doping concentration.

[0055] Figure 3 (c) and (d) are graphene source doping carrier concentrations of 5 × 10⁻⁶. 19 e / cm 3 The relationship between the carrier concentration distribution at 0 gate voltage and 0.2V gate voltage and the position of the molybdenum disulfide conduction band bottom in the channel is shown. At this doped carrier concentration, the molybdenum disulfide conduction band bottom in the channel is exactly within the band gap near the source Dirac point at 0 gate voltage, and the carrier concentration at the Dirac band gap is zero. Here, the formation of the Dirac band gap is due to the interaction between graphene and molybdenum disulfide disrupting the symmetry of the graphene band structure. Figure 3 As shown in (c) and (d), during the process of changing the gate voltage from 0 to 0.2V (corresponding to the device switching from off to on), the source carrier concentration changes from zero to a large value. The abrupt change in the source carrier concentration in the subthreshold region results in a large current change in the device within this gate voltage range, thus exhibiting a steep SS value. The calculated SS value is 48mV / decade.

[0056] Furthermore, the inventors calculated that when the graphene source doping concentration is 3×10⁻⁶, 19 e / cm 3and 7×10 19 e / cm 3 During this period, the SS value of the Dirac source device exceeded the limit of 60mV / decade.

[0057] In summary, if the doping concentration of the graphene source electrode is too high or too low, the source carriers will fluctuate within a very low or very high concentration range during device switching, making it difficult to achieve a rapid change in the number of source carriers and thus hindering the acquisition of a steep SS value. Therefore, it is necessary to select an appropriate doping concentration so that the graphene source carriers can fluctuate within a very low to very high concentration range during device switching, thereby achieving a rapid change in the number of source carriers.

[0058] In this embodiment, the n-type doping concentration of the molybdenum disulfide drain is 3 × 10⁻⁶. 20 e / cm 3 The optimal graphene source doping concentration is 5 × 10⁻⁶. 19 e / cm 3 .

[0059] Furthermore, a larger Dirac gap facilitates the manipulation of interface band alignment through doping concentration. This embodiment employs a graphene / molybdenum disulfide planar heterojunction, where strong interactions at the interface generate a Dirac gap at the graphene Dirac point. This embodiment fully utilizes this Dirac gap, ensuring that the molybdenum disulfide conduction band bottom is precisely within this gap during the device's off-state. This results in zero source polar state density and zero carrier concentration, causing a sudden change in source carrier concentration during device switching, which further helps reduce the SS value.

[0060] While van der Waals vertical heterojunctions in related technologies can also open the Dirac gap, the opening gap is only a few to tens of meV due to the weak van der Waals interaction. In contrast, the graphene / molybdenum disulfide planar heterojunction in this embodiment opens a Dirac gap of approximately 50 meV, which is larger than the Dirac gap of most van der Waals planar heterojunctions. This is another advantage of using planar heterojunctions to fabricate Dirac source devices.

[0061] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0062] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0063] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0064] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0065] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0066] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A Dirac source device capable of rapid switching, characterized in that, include: A first electrode, the first electrode including a source material layer, the source material having a Dirac cone band structure; The second electrode includes a two-dimensional material layer; The channel region is located between the first electrode and the second electrode in a first extending direction, which is the length or width direction of the Dirac source device. The channel region includes a channel layer, which has a first end and a second end opposite to each other in the first extending direction. The first end of the channel layer is covalently connected to the source material layer to form a planar heterojunction, and the second end of the channel layer is connected to the two-dimensional material layer. The channel layer of the channel region is a molybdenum disulfide channel layer. The channel region also includes two silicon dioxide dielectric layers and two metal gate layers. The molybdenum disulfide channel layer is sandwiched between the two silicon dioxide dielectric layers, and the two metal gate layers sandwich the molybdenum disulfide channel layer and the silicon dioxide dielectric layer.

2. The Dirac source device capable of rapid switching according to claim 1, characterized in that, The source material is graphene or graphene-like material.

3. The Dirac source device capable of rapid switching according to claim 2, characterized in that, The source material layer is a single-layer graphene layer or a single-layer graphene-like layer.

4. The Dirac source device capable of rapid switching according to claim 1, characterized in that, The two-dimensional material layer is a molybdenum disulfide layer; and / or, the channel layer is a molybdenum disulfide channel layer.

5. The Dirac source device capable of rapid switching according to any one of claims 1-4, characterized in that, The first electrode includes a source material extension region extending from the source material layer and used to connect to a first end of the channel layer; and / or, the second electrode includes a two-dimensional material extension region extending from the two-dimensional material layer and connected to a second end of the channel layer.

6. The Dirac source device capable of rapid switching according to claim 1, characterized in that, The source material layer is a single-layer graphene layer, and the channel layer is a molybdenum disulfide channel layer. The molybdenum disulfide channel layer includes two sulfur atom layers and one molybdenum atom layer. The molybdenum atom layer is sandwiched between the two sulfur atom layers to form a sandwich structure. The sulfur atom layer is bonded to the graphene layer to form a graphene-molybdenum disulfide planar heterojunction.

7. The rapidly switchable Dirac source device according to claim 6, characterized in that, The source material layer is a single-layer graphene layer, the channel layer is a molybdenum disulfide channel layer, the two-dimensional material layer is a molybdenum disulfide layer, and the graphene layer is p-type doped with a carrier concentration ranging from 3 × 10⁻⁶. 19 e / cm 3 -7×10 19 e / cm 3 The molybdenum disulfide layer is n-type doped with a carrier concentration of 3 × 10⁻⁶. 20 e / cm 3 .

8. The Dirac source device capable of rapid switching according to claim 7, characterized in that, The carrier concentration of the graphene layer is 5 × 10⁻⁶. 19 e / cm 3 .

9. The Dirac source device capable of rapid switching according to claim 1, characterized in that, The channel length of the Dirac source device is in the sub-ten nanometer range.

10. The fast-switching Dirac source device according to any one of claims 6-9, characterized in that, Stress is applied to the source material layer.

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