Method for regulating and controlling carriers of two-dimensional semiconductor material by using ionic Van der Waals single crystal Sb4O5Cl2
By using ionic van der Waals single crystal Sb4O5Cl2 nanosheets as dielectric layers in two-dimensional semiconductor materials and regulating the migration of Cl ions using polarized electric fields, efficient regulation and reconfigurability of channel carrier concentration of two-dimensional semiconductor materials is achieved, and the problems of low efficiency and poor retention in the prior art are solved.
Patent Information
- Application Number
- CN202510229875.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-28
- Publication Date
- 2025-05-30
AI Technical Summary
The existing two-dimensional semiconductor material carrier control methods are inefficient, poor retention, and cannot be reconstructed, which cannot meet the further application and development of two-dimensional semiconductor devices.
Using the ionic van der Waals single crystal Sb4O5Cl2 nanosheets as the dielectric layer of the two-dimensional semiconductor material channel, ion-electron coupling and decoupling are achieved at the dielectric layer-two-dimensional semiconductor channel interface through polarized electric fields in the same direction, thereby regulating the channel carrier concentration.
It realizes efficient regulation of the carrier concentration of two-dimensional semiconductor materials, has reconfigurability and good nonvolatile properties, and can achieve reversible conversion between different conductivity states.
Smart Images
Figure CN120076392A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of two-dimensional material preparation, and more specifically, relates to a method for regulating carriers of two-dimensional semiconductor materials by using ionic van der Waals single crystal Sb 4 O 5 Cl 2 Background Art Background Art
[0002] Due to their ultra-thin atomic size, clean surface without dangling bonds, strong light-matter interaction, and tunable bandgap, two-dimensional semiconductor materials are ideal carriers for next-generation optoelectronic devices and are thus considered promising to replace current traditional silicon-based semiconductor materials. Currently, extensive research on optoelectronic devices based on two-dimensional semiconductor materials has been reported and successfully applied in fields such as information storage, photodetection, and infrared imaging.
[0003] In optoelectronic devices, the regulation of channel carrier concentration is crucial. However, due to the ultra-thin structure of two-dimensional materials, the ion implantation and high-temperature diffusion methods in traditional semiconductor processes are no longer applicable. Although certain progress has been made in doping methods for two-dimensional semiconductor materials in recent years, including methods such as ion exchange and surface charge transfer, these methods all have certain drawbacks. For example, they cannot be maintained for a long time, introduce additional defects, have limited carrier regulation levels, and the doping process cannot be reversibly reconstructed. Therefore, they still cannot meet the further application and development of two-dimensional semiconductor devices. Summary of the Invention
[0004] To address the above problems, the present invention uses ionic van der Waals single crystal Sb 4 O 5 Cl 2 nanosheets as the dielectric layer of the channel of two-dimensional semiconductor materials, and uses the polarization electric field in the same direction to achieve ion-electron coupling and decoupling at the dielectric layer-two-dimensional semiconductor channel interface, thereby achieving the regulation of channel carrier concentration, and thus solving the problems of low efficiency, poor retention, and non-reconstructability of existing two-dimensional material carrier regulation methods. According to the object of the present invention, there is provided a method for regulating carriers of two-dimensional semiconductor materials by using ionic van der Waals single crystal Sb 4 O 5 Cl 2 Release the exfoliated single crystal nanosheets Sb 4 O 5 Cl 2 on the substrate using a thermal release adhesive, then spin-coat and dry a polypropylene carbonate solution, and then use polydimethylsiloxane to lift off the polypropylene carbonate together with Sb 4 O 5 Cl 2 single crystal nanosheets, and then release the polypropylene carbonate and Sb by heating4 O 5 Cl 2 Transfer it onto the two-dimensional semiconductor material supported on the substrate as the dielectric layer, form contacts through van der Waals forces, and use an organic solvent to dissolve and remove the excess polypropylene carbonate; then evaporate a metal electrode on the dielectric layer as the top gate electrode, and evaporate source and drain electrodes at both ends of the two-dimensional semiconductor material.
[0005] Realize Sb 4 O 5 Cl 2 Vertical migration of Cl ions in the single-crystal nanosheets, and achieve ion-electron coupling at the dielectric layer-two-dimensional semiconductor material channel interface, thereby achieving the regulation of the carrier concentration in the two-dimensional semiconductor material channel.
[0006] Preferably, under the action of a negative gate voltage, Sb 4 O 5 Cl 2 Cl ions in the single-crystal nanosheets accumulate at the channel interface, capturing holes in the channel to increase the electron concentration.
[0007] Preferably, under the action of a positive gate voltage, Sb 4 O 5 Cl 2 Cl ions in the single-crystal nanosheets move away from the channel interface, releasing holes in the channel to decrease the electron concentration.
[0008] Preferably, the two-dimensional semiconductor material is MoS 2 、MoSe 2 、or WS 2 .
[0009] Preferably, the preparation method of the single-crystal nanosheet Sb 4 O 5 Cl 2 is: Using the chemical vapor transport method, using Sb 2 O 3 and SbCl 3 as reaction sources to prepare the single-crystal nanosheet Sb 4 O 5 Cl 2 , and the molar ratio of the Sb 2 O 3 and SbCl 3 is (4-6):(1-3).
[0010] Preferably, the organic solvent is acetone.
[0011] Preferably, the lower-layer metal of the top gate electrode and the source and drain electrodes is In, and the upper-layer metal is Au.
[0012] Generally speaking, compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:
[0013] (1) The present invention uses the ionic van der Waals material Sb 4 O 5 Cl 2 as the dielectric layer of the two-dimensional semiconductor material channel, and realizes the vertical migration of Cl ions in Sb 4 O 5 Cl 2 under the action of polarization electric fields in different directions, and realizes ion-electron coupling at the dielectric layer-two-dimensional semiconductor channel interface, so as to achieve the regulation of the carrier concentration in the channel, with the characteristics of high regulation efficiency and reconfigurable effect. Under the action of the negative gate voltage, Cl ions in Sb 4 O 5 Cl 2 accumulate at the channel interface, capture holes in the channel to increase the electron concentration. On the contrary, under the action of the positive gate voltage, Cl ions in Sb 4 O 5 Cl 2 move away from the channel interface, release holes in the channel to reduce the electron concentration.
[0014] (2) Since the migration of Cl ions in the present invention has the characteristics of reversibility and room temperature retention, the mutual conversion of different conductances of the two-dimensional semiconductor material is realized, and the fabricated device has the reconfigurable high and low conductance switching cyclicity and good non-volatile characteristics.
[0015] (3) The method for regulating the carriers of the two-dimensional semiconductor material by using the ionic van der Waals single crystal Sb 4 O 5 Cl 2 has no destructive effect on the structure of the two-dimensional material. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 is a schematic diagram of the high-quality Sb 4 O 5 Cl 2 single crystal prepared by the chemical vapor transport method in Example 1.
[0017] Figure 2 is a schematic diagram of the preparation method of the Sb 4 O 5 Cl 2 / MoS 2 top-gate device in Example 1.
[0018] Figure 3 is the optical image of the device in Example 1.
[0019] Figure 4 is the atomic force image of the device in Example 1.
[0020] Figure 5 In [a], after the device in Example 1 was polarized with a gradually increasing negative gate voltage at the top gate, the carrier concentration of MoS 2 increased, and it is the back-gate transfer characteristic curve diagram when it changed from a semiconductor to a metal phase.
[0021] Figure 5 In [b], after the device in Example 1 was polarized with a gradually increasing positive gate voltage at the top gate, the carrier concentration of MoS 2 decreased, and it is the back-gate transfer characteristic curve diagram when it changed from a metal phase to a semiconductor.
[0022] Figure 6 is the transfer characteristic curve of the back-gate device after the device in Example 2 was polarized with positive and negative top-gate voltages for 100 cycles.
[0023] Figure 7 In [a], it is the back-gate FET on / off ratio of the metal phase and the semiconductor phase extracted after the device in Example 2 was polarized with positive and negative top-gate negative voltages for 100 cycles.
[0024] Figure 7 In [b], it is the conductance of the metal phase and the semiconductor phase at different back-gate voltages extracted after the device in Example 2 was polarized with positive and negative top-gate voltages for 100 cycles.
[0025] Figure 8 is the mechanism diagram of the ionic van der Waals single crystal Sb 4 O 5 Cl 2 for regulating the carriers of two-dimensional semiconductor materials. Detailed implementation manners
[0026] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0027] The present invention uses the ionic van der Waals single crystal Sb 4 O 5 Cl 2 to regulate the carriers of two-dimensional materials. The present invention transfers the high-quality Sb 4 O 5 Cl 2 obtained by chemical vapor synthesis method to the two-dimensional semiconductor material (such as MoS 2 substrate after peeling, and fixed-point transfer to the SiO2 ) to form a top dielectric layer, and then gold is evaporated as the top gate electrode. The fabricated device can achieve effective regulation of the channel carriers of two-dimensional semiconductor materials (such as MoS 2 ) and the function of high and low conductivity conversion. The regulation process exhibits good reconfigurability and non-volatility characteristics.
[0028] In some embodiments, the chemical vapor synthesis method is adopted, and Sb with a stoichiometric ratio of (4-6):(1-3) 2 O 3 and SbCl 3 are used as reaction sources to prepare Sb 4 O 5 Cl 2 single crystal, and centimeter-scale Sb 4 O 5 Cl 2 single crystal with high crystal quality and low defects is obtained.
[0029] In some embodiments, tape is used to exfoliate bulk Sb 4 O 5 Cl 2 single crystal, and then the exfoliated single crystal nanosheets are released on a clean SiO 2 substrate by using a thermal release adhesive. Subsequently, polypropylene carbonate (PPC) is spin-coated and dried. Finally, PDMS is used to lift off the PPC together with the Sb 4 O 5 Cl 2 single crystal nanosheets, and then the nanosheets are transferred to the two-dimensional material by the fixed-point transfer method, and the excess PPC is removed with acetone.
[0030] In some embodiments, the thin film prepared on the substrate is transferred to the two-dimensional material by the fixed-point transfer method to form a contact through van der Waals force.
[0031] In some embodiments, two-dimensional semiconductor MoS 2 is used as the channel, and MoS 2 single crystal is exfoliated by mechanical exfoliation method to obtain MoS 2 nanosheets and transferred to a SiO 2 substrate. Subsequently, the Sb 4 O 5 Cl 2 single crystal nanosheets are transferred to MoS 2 by the above method, and then the source and drain electrodes are evaporated, together with the top gate electrode.
[0032] The present invention relates to a method for regulating the carriers of two-dimensional semiconductor materials by using ionic van der Waals single crystal Sb 4 O 5 Cl 2 By using Sb 4 O5 Cl 2 As a carrier regulation layer, single-crystalline nanosheets are transferred to two-dimensional materials at fixed points. Through Sb 4 O 5 Cl 2 The ion migration of Cl ions in the single crystal realizes the coupling and decoupling with the carriers in the two-dimensional semiconductor channel under electric fields in different directions, so as to achieve the effect of carrier regulation; due to the reversibility and room-temperature retention of Cl ion migration, the carrier regulation effect has the characteristics of reconfigurability and non-volatility.
[0033] In the present invention, by transferring Sb 4 O 5 Cl 2 single-crystalline nanosheets to two-dimensional materials as a dielectric layer and evaporating a metal electrode on the dielectric layer as the top gate, ion-electron coupling and decoupling are realized at the dielectric layer-two-dimensional semiconductor channel interface through electric field polarization in different directions, so as to achieve the effect of regulating the carrier concentration in the channel.
[0034] The electronic device constructed by the present invention using two-dimensional semiconductors (such as MoS 2 ) as the semiconductor channel material exhibits excellent optoelectronic properties.
[0035] Combining the structure of a two-dimensional semiconductor (such as MoS 2 ) back-gate FET device, the present invention uses Sb 4 O 5 Cl 2 single-crystalline nanosheets as the dielectric layer and evaporating the top gate, and regulating the carriers in the two-dimensional semiconductor (such as MoS 2 ) channel through electric field polarization in different directions, so that the two-dimensional semiconductor (such as MoS 2 ) back-gate FET device can be reconfigurably transformed between a high-conductivity metal phase and a low-conductivity semiconductor phase.
[0036] In some embodiments, MoS 2 single crystals are obtained by mechanical exfoliation to obtain MoS 2 nanosheets and transferred to a SiO 2 substrate. SiO 2 is used as the back dielectric layer, and Sb 4 O 5 Cl 2 single-crystalline nanosheets are transferred as the top dielectric layer. Subsequently, source and drain electrodes are evaporated at both ends of the semiconductor material, and a top gate electrode is evaporated on the Sb 4 O 5 Cl 2 single-crystalline nanosheets.
[0037] The following are specific embodiments
[0038] Example 1
[0039] As Figure 1 shown, high-quality Sb 4 O 5 Cl 2 single crystals were prepared by chemical vapor transport method. Using the preparation method shown Figure 2 , first, the bulk Sb 4 O 5 Cl 2 single crystal was peeled off with tape, and then the single crystal nanosheets of Sb 4 O 5 Cl 2 obtained by peeling were released on a clean SiO 2 substrate. Subsequently, PPC was spin-coated and dried, and finally PDMS was used to lift off the PPC together with the Sb 4 O 5 Cl 2 single crystal nanosheets. Then, the PPC together with the Sb 4 O 5 Cl 2 single crystal nanosheets were transferred to MoS 2 on the SiO 2 substrate by thermal release. Subsequently, PPC was removed by soaking in acetone solution. Finally, In / Au was evaporated as the source-drain electrode and the top gate electrode. The optical and atomic force images of the fabricated device are shown in Figure 3 and Figure 4 . Under the gradually increasing top gate polarization voltages in different directions, the mutual transformation between the semiconductor phase and the metal phase of MoS 2 was achieved. The back gate transfer characteristic curves of MoS 2 during the two-phase transformation process are shown in Figure 5 a (the semiconductor phase transforms into the metal phase under negative gate voltage polarization) and Figure 5 b (the metal phase transforms into the semiconductor phase under positive gate voltage polarization) in
[0040] Example 2
[0041] Example 1 was repeated with the same steps as described above, except that the Sb 4 O 5 Cl 2 nanosheets had a thicker thickness. Subsequently, the device was cyclically polarized 100 times to test the cyclic stability of its carrier concentration regulation ability. The back gate FET curves under 100 cycles are shown in Figure 6 . Figure 7 is Figure 6 the switching ratio of the two phases and the conductance under different back gate voltages extracted from
[0042] Result Analysis
[0043] Figure 1 is the preparation method of high-quality Sb 4 O 5 Cl 2 single crystal in Example 1. With a certain proportion of Sb 2 O 3 and SbCl 3 as the reaction sources, they are hermetically sealed in a quartz tube under high vacuum, and then placed in a two-temperature-zone tube furnace for reaction (the high-temperature zone is 550 °C, and the low-temperature zone is 450 °C), and the reaction sources are placed in the high-temperature zone.
[0044] Figure 2 is the schematic diagram of the preparation method of Sb 4 O 5 Cl 2 / MoS 2 top-gate device. The MoS 2 single crystal is obtained by mechanical exfoliation, and the MoS 2 nanosheets are transferred to the SiO 2 / Si substrate. The bulk Sb 4 O 5 Cl 2 single crystal is exfoliated using tape, and then the exfoliated single-crystal nanosheets are released onto a clean SiO 2 / Si substrate using a thermal release adhesive. Subsequently, PPC is spin-coated and dried, and finally, PDMS is used to lift off the PPC together with the Sb 4 O 5 Cl 2 single-crystal nanosheets, and then the nanosheets are transferred to MoS 2 by a fixed-point transfer method. Finally, In / Au is evaporated as the source-drain electrode and the top-gate electrode.
[0045] Figure 3 and Figure 4 are the optical microscope image and atomic force image of the Sb 4 O 5 Cl 2 / MoS 2 top-gate device prepared in Example 1. It can be seen that the surface of the device is flat and has good uniformity.
[0046] Figure 5 a in Figure 5 and b in 4 O 5 Cl 2 / MoS 2 are the back-gate FET transfer characteristic curves of the top-gate device after being polarized by the top-gate voltage in different directions in Example 1. The results show that the semiconductor phase transforms into the metal phase under negative gate voltage polarization. Subsequently, under the gradual application of positive gate voltage polarization to the top gate, MoS2 The transformation from the metallic phase to the semiconductor phase.
[0047] Figure 6 is the Sb prepared in Example 2 4 O 5 Cl 2 / MoS 2 The back-gate FET transfer curves of the top-gate device under the action of cyclic gate voltages in different directions of the top gate. The results show that the device has good reconfigurability and can still achieve the mutual transformation between the metallic phase and the semiconductor phase under 100 cycles of top-gate voltages.
[0048] Figure 7 a in Figure 7 and b in Figure 6 are respectively the switching ratio between the metallic phase and the semiconductor phase and the conductances of the two phases under different back-gate voltages extracted from the back-gate FET transfer curves in 6 . The results show that after 100 cycles, the semiconductor phase can still have a relatively high switching ratio of 10 -4 , while the switching of the metallic phase remains in single digits; in addition, the conductance of the metallic phase remains at about 10 bg S, which is three orders of magnitude higher than that of the semiconductor phase (V
[0049] Figure 8 is Sb 4 O 5 Cl 2 regulates the mechanism diagram of the channel carriers in MoS 2 . Under the negative-polarized gate voltage, Cl ions approach the MoS 2 interface, capture holes in the channel, increase the electron concentration, and thus make MoS 2 transform from semiconductor to metal. Under the positive-polarized gate voltage, Cl ions move away from the MoS 2 interface, leaving holes, capturing electrons in the channel, reducing the electron concentration, and thus making MoS 2 transform back from metal to semiconductor.
[0050] It is easy for those skilled in the art to understand that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.
Claims
1. A method for regulating the carriers of two-dimensional semiconductor materials using ionic van der Waals single crystal Sb4O5Cl2, characterized in that: The single crystal nanosheet Sb4O5Cl2 obtained by peeling is released on the substrate by using a thermal release adhesive, and then a polypropylene carbonate solution is spin-coated and dried, and then polypropylene carbonate and the Sb4O5Cl2 single crystal nanosheet are peeled off using polydimethylsiloxane, and then the polypropylene carbonate and Sb4O5Cl2 are transferred to the two-dimensional semiconductor material loaded on the substrate as a dielectric layer by heating release, and contact is formed by van der Waals force, and the excess polypropylene carbonate is dissolved and removed by using an organic solvent; Then, a metal electrode is evaporated on the dielectric layer as a top gate electrode, and a source and drain electrode is evaporated on both ends of the two-dimensional semiconductor material; By realizing the vertical migration of Cl ions in Sb4O5Cl2 single crystal nanosheets under the action of polarized electric fields in different directions, and realizing ion-electron coupling at the interface between the dielectric layer and the two-dimensional semiconductor material channel, the carrier concentration in the two-dimensional semiconductor material channel can be regulated.
2. The method for regulating the carriers of two-dimensional semiconductor materials using ionic van der Waals single crystal Sb4O5Cl2 as claimed in claim 1, characterized in that: Under the action of negative polarization gate voltage, Cl ions in Sb4O5Cl2 single crystal nanosheets accumulate at the channel interface, capturing holes in the channel to increase the electron concentration.
3. The method for regulating the carriers of two-dimensional semiconductor materials using ionic van der Waals single crystal Sb4O5Cl2 as claimed in claim 1, characterized in that: Under the action of positive polarization gate voltage, Cl ions in Sb4O5Cl2 single crystal nanosheets move away from the channel interface, releasing holes in the channel to reduce the electron concentration.
4. The method for regulating the carriers of two-dimensional semiconductor materials using ionic van der Waals single crystal Sb4O5Cl2 as claimed in claim 1, characterized in that: The two-dimensional semiconductor material is MoS2, MoSe2, or WS2.
5. The method for regulating the carriers of two-dimensional semiconductor materials using ionic van der Waals single crystal Sb4O5Cl2 as claimed in claim 1, characterized in that: The preparation method of the single crystal nanosheet Sb4O5Cl2 is as follows: a chemical vapor transport method is used to prepare the single crystal nanosheet Sb4O5Cl2 using Sb2O3 and SbCl3 as reaction sources, wherein the molar ratio of the Sb2O3 and SbCl3 substances is (4-6): (1-3).
6. The method for regulating the carriers of two-dimensional semiconductor materials using ionic van der Waals single crystal Sb4O5Cl2 as claimed in claim 1, characterized in that: The organic solvent is acetone.
7. The method for regulating the carriers of two-dimensional semiconductor materials using ionic van der Waals single crystal Sb4O5Cl2 as claimed in claim 1, characterized in that: The bottom metal of the top gate electrode and the source-drain electrode is In, and the top metal is Au.