Black phosphorus-borate polymer heterojunction material, and preparation method therefor and use thereof
By forming a borate polymer shell on the surface of black phosphorus, the stability problem of black phosphorus under environmental conditions was solved, thus improving the performance of field-effect transistors.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- XIAMEN UNIV
- Filing Date
- 2025-12-10
- Publication Date
- 2026-06-18
AI Technical Summary
Existing technologies struggle to improve the stability of black phosphorus under environmental conditions, particularly its oxidation and humidity stability, while maintaining its semiconductor performance. Furthermore, existing packaging methods may damage the crystal structure or reduce humidity stability.
Boronate polymer (BEP) was prepared using catechol and boric acid monomers as a shell. Through the surface bonding of catechol and the driving force of B←N coordination bond, BEP was encapsulated on the surface of two-dimensional black phosphorus (2D-BP) to form a heterojunction material, which blocked the contact between oxygen and water molecules and 2D-BP.
The air stability of 2D-BP is significantly improved, and the switching ratio of the field-effect transistor is increased, power consumption is reduced, signal response speed and noise immunity are enhanced through enhanced BEP shell thickness adjustment.
Smart Images
Figure CN2025141486_18062026_PF_FP_ABST
Abstract
Description
A black phosphorus-boron ester polymer heterojunction material, its preparation method and application
[0001] Cross-references to related applications
[0002] This application claims priority to and is based on Chinese Patent Application No. 202411824167X, filed with the China National Intellectual Property Administration on December 12, 2024, entitled "A Black Phosphorus-Borate Acid Polymer Heterojunction Material and Its Preparation Method and Application", the contents of which are incorporated herein by reference. Technical Field
[0003] This invention belongs to the field of electronic devices, specifically relating to a black phosphorus-boron ester polymer heterojunction material, its preparation method, and its application. Background Technology
[0004] Among numerous two-dimensional (2D) materials, black phosphorus (BP) stands out for its thickness-dependent direct bandgap (tunable between 0.3 and 2.0 eV), its ultra-high carrier mobility second only to graphene, and its in-plane anisotropy in electrical, mechanical, and optical properties. Few-layer BP and monolayer phosphoradiene have wide applications in fields such as field-effect transistors (FETs), batteries, photodetectors, supercapacitors, and catalysis.
[0005] Recent advances in bottom-up and top-down synthesis techniques have enabled precise control over the structure and morphology of phosphorus compounds (BP), offering a wide range of possibilities for improving their semiconductor properties. However, in BP, each P atom forms a PP bond with three adjacent P atoms, resulting in a lone pair of electrons on each P atom. Therefore, BP readily reacts with oxygen to form substances such as phosphorus oxide (POx), which in turn reacts with H₂O to form phosphoric acid. Improving the stability of BP under environmental conditions while maintaining its inherent semiconductor properties remains a significant challenge.
[0006] In recent years, passivation strategies for black phosphorus (BP) have mainly relied on the absorption or covalent attachment of ions (Zhi N, Si C, Zhong Z, et al. Metal-Ion-Modified Black Phosphorus with Enhanced Stability and Transistor Performance[J]. Advanced Materials, 2017.) through interaction with the lone pair electrons of P atoms. These strategies can effectively reduce the redox activity of P atoms and improve antioxidant capacity. However, highly hygroscopic ions reduce the humidity stability of BP. Due to the lack of specific supramolecular driving forces, encapsulating BP in semiconductor polymers requires a covalent modification process, which may damage the crystal structure of BP. In addition, encapsulating BP with metal oxide thin films usually employs an evaporation method, causing atomic penetration of BP and degrading its semiconductor performance (Dian Z, Zhi J, Chuan H, et al. Effective passivation of black phosphorus transistor against ambient degradation by an ultra-thin tin oxide film, 2019.). Summary of the Invention
[0007] The purpose of this invention is to overcome the defects of the prior art and provide a black phosphorus-boron ester polymer heterojunction material.
[0008] Another object of the present invention is to provide a method for preparing the above-mentioned black phosphorus-boron ester polymer heterojunction material.
[0009] Another object of the present invention is to provide the application of the above-mentioned black phosphorus-boronate polymer heterojunction material.
[0010] The technical solution of the present invention is as follows:
[0011] A black phosphorus-boron ester polymer heterojunction material comprises, from the inside out, a SiO2 / Si substrate, a 2D-BP deposition layer, and at least a BEP shell, wherein,
[0012] The structural formula of BEP in the BEP shell is:
[0013] The preparation method of the above-mentioned black phosphorus-boron ester polymer heterojunction material includes the following steps:
[0014] (1) 2D-BP is deposited on the surface of a SiO2 / Si substrate to form the 2D-BP deposition layer;
[0015] (2) At room temperature, the material obtained in step (1) is soaked in anhydrous ethanol, then TC solution is added and allowed to stand for reaction, and then TB solution is added and allowed to stand for reaction to obtain the product.
[0016] The structural formula of TC in the above TC solution is:
[0017] The structural formula of TB in the above TB solution is:
[0018] In a preferred embodiment of the present invention, the synthetic route of TC is as follows:
[0019] In a preferred embodiment of the present invention, the synthetic route of TB is as follows:
[0020] In a preferred embodiment of the present invention, step (1) is: dropping 2D-BP dispersion onto the SiO2 / Si substrate, allowing the solvent to evaporate, and then annealing in a vacuum at 180°C for 30 min.
[0021] More preferably, in step (2), the standing reaction time after adding TC solution is 0.5-1h.
[0022] More preferably, in step (2), the standing reaction time after adding TB solution is 10-14 hours.
[0023] More preferably, in step (2), the standing reaction time after adding TC solution is 0.5-1h, and the standing reaction time after adding TB solution is 10-14h.
[0024] The above-mentioned black phosphorus-boron ester polymer heterojunction material is used in the fabrication of field-effect transistors.
[0025] A field-effect transistor, wherein the channel material is the aforementioned black phosphorus-boron ester polymer heterojunction material.
[0026] The beneficial effects of this invention are:
[0027] 1. This invention encapsulates borate ester polymers (BEP) on a two-dimensional material using catechol and boric acid monomers, based on the combined driving force of catechol surface bonding and B←N coordination bonds. The slightly oxidized 2D-BP contains trace amounts of oxygen-containing groups, providing binding sites for catechol groups. In addition, the lone pair electrons of the P atoms on the 2D-BP surface can interact with the empty orbitals of the B atoms in BEP, further promoting the assembly of BEP on the 2D-BP surface. Therefore, the polycondensation between catechol and boric acid monomers can be confined to the surface of 2D-BP.
[0028] 2. The two driving forces described above in this invention enable BEP to form a shell layer on the surface of 2D-BP, and the thickness of the BEP shell layer can be changed by adjusting the concentrations of catechol and boric acid monomers. The formation of the BEP shell layer blocks the direct contact between oxygen molecules and water molecules in the air and 2D-BP, thereby significantly improving the stability of 2D-BP in the air.
[0029] 3. The BP-BEP heterojunction material of the present invention can be used as a channel material to fabricate field-effect transistors (FETs). The coating of BEP can improve the on / off ratio of the BP FET. The increase in the on / off ratio can further reduce its power consumption, improve its signal response speed and enhance its noise immunity. Attached Figure Description
[0030] Figure 1 shows an optical microscope image and an atomic force microscope (AFM) image of the 2D-BP prepared in Example 1 of the present invention.
[0031] Figure 2 shows the AFM images of the 2D-BP and BP-BEPs heterojunction materials prepared in Example 3 of the present invention.
[0032] Figure 3 shows the AFM images of the 2D-BP and BP-BEPs heterojunction materials prepared in Example 4 of the present invention.
[0033] Figure 4 shows the AFM images of the 2D-BP and BP-BEPs heterojunction materials prepared in Example 5 of the present invention.
[0034] Figure 5 shows the AFM diagrams of the 2D-BP and BP-BEP heterojunction materials prepared in Comparative Example 1 and Examples 3 to 5 of the present invention as a function of time.
[0035] Figure 6 shows the Raman diagrams of the 2D-BP obtained in Comparative Example 1 and the BP-BEPs heterojunction materials obtained in Examples 3 to 5 of the present invention.
[0036] Figure 7 shows the infrared spectra of 2D-BP prepared in Comparative Example 1, TC prepared in Example 2, and BP-TC prepared in Example 3.
[0037] Figure 8 shows the transfer characteristic curves of the 2D-BP FET prepared in Comparative Example 1 and the BP-BEPs FET prepared in Example 3 of the present invention. Detailed Implementation
[0038] The technical solution of the present invention will be further explained and described below with reference to specific embodiments and accompanying drawings.
[0039] Example 1
[0040] The methods for preparing the SiO2 / Si substrates with 2D-BP deposited in Examples 3 to 5 and Comparative Example 1 are as follows:
[0041] The 2D-BP dispersion was dropped onto a SiO2 / Si substrate and slowly purged with nitrogen gas. After the solvent evaporated, it was thermally annealed at 180°C for 30 minutes under vacuum. As shown in Figure 1, the thickness of the obtained 2D-BP was only 6.67 nm.
[0042] Example 2
[0043] The preparation methods of TC and TB used in Examples 3 to 5 below are as follows (refer to patent CN107082411A):
[0044] (1) Synthesis of TC: Tris(4-aminophenyl)amine (14.5 mg, 0.05 mmol) was dissolved in 5 mL of anhydrous ethanol, and then 3,4-dihydroxybenzaldehyde (20.7 mg, 0.15 mmol) was added. The mixture was stirred at room temperature in the dark for 12 h to obtain 5 mL of TAC solution with a concentration of 10 mmol / L.
[0045] (2) Synthesis of TB: Tris(4-aminophenyl)amine (14.5 mg, 0.05 mmol) was dissolved in 5 mL of anhydrous ethanol, and then 4-formylphenylboronic acid (22.5 mg, 0.15 mmol) was added. The mixture was stirred at room temperature in the dark for 12 h to obtain 5 mL of TB solution with a concentration of 10 mmol / L.
[0046] Example 3
[0047] At room temperature, the SiO2 / Si substrate with 2D-BP deposited as prepared in Example 1 was immersed in 5 mL of anhydrous ethanol, followed by the addition of 25 μL of TC solution prepared in Example 2. After standing for 1 h, 25 μL of TAB solution prepared in Example 2 was added, and the mixture was allowed to stand for 12 h to obtain the BP-BEPs heterojunction material. As shown in Figure 2, the thickness of the BEP shell of this BP-BEPs heterojunction material is 7.7 nm (denoted as BP-BEP). 7.7 ).
[0048] Example 4
[0049] At room temperature, the SiO2 / Si substrate with 2D-BP deposited as prepared in Example 1 was immersed in 5 mL of anhydrous ethanol, followed by the addition of 50 μL of TC solution prepared in Example 2. After standing for 1 h, 50 μL of TB solution prepared in Example 2 was added, and the mixture was allowed to stand for 12 h to obtain the BP-BEPs heterojunction material. As shown in Figure 3, the thickness of the BEP shell of this BP-BEPs heterojunction material is 13.3 nm (denoted as BP-BEP). 13.3 ).
[0050] Example 5
[0051] At room temperature, the SiO2 / Si substrate with 2D-BP deposited as prepared in Example 1 was immersed in 5 mL of anhydrous ethanol, followed by the addition of 75 μL of TC solution prepared in Example 2. After standing for 1 h, 75 μL of TB solution prepared in Example 2 was added, and the mixture was allowed to stand for 12 h to obtain the BP-BEPs heterojunction material. As shown in Figure 4, the thickness of the BEP shell of this BP-BEPs heterojunction material is 16.5 nm (denoted as BP-BEP). 16.5 ).
[0052] Comparative Example 1
[0053] Comparative Example 1 is a SiO2 / Si substrate with 2D-BP deposited without BEP coating prepared in Example 1.
[0054] As shown in Figure 5, using Comparative Example 1 as a control, it can be observed that the stability of uncoated 2D-BP in air is far inferior to that of the BEP-coated BP-BEP heterojunction material. Pure 2D-BP, after only 12 hours of exposure to air, showed a small number of bubbles on its surface; after 24 hours, the bubbles gradually increased in size, indicating a deeper degree of oxidation. In contrast, the BEP-coated BP-BEP heterojunction material only showed a small number of bubbles on its surface after 15 days of exposure to air.
[0055] As shown in Figure 6, after BEP coats BP, the B atoms in BEP form B←P coordinate bonds with the P atoms in 2D-BP, causing the Raman shift of the BO bond to increase from 1356.5 cm⁻¹. -1 The offset has reached 1364cm -1 It also affected the Raman shift of the C / C bond on the benzene ring connected to the BO bond (from 1588 cm⁻¹). -1 Redshifted to 1583cm -1 As shown in Figure 7, the CO bond on TC starts from 1279 cm⁻¹. -1 Redshifted to 1269cm -1 This indicates that the catechol groups on TC form hydrogen bonds with the oxides on 2D-BP, driving TC to adsorb onto the surface of 2D-BP.
[0056] As shown in Figure 8, BEP coats 2D-BP to form BP-BEP. 7.7 After heterojunction, BP-BEP 7.7 The FET's on / off ratio is 4.35 × 10⁻⁶. 5 The on / off ratio of the BP FET is only 4×10. 5 .
[0057] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention. Industrial applicability
[0058] This invention discloses a black phosphorus-boron ester polymer heterojunction material, its preparation method, and its application. From the inside out, it comprises a SiO2 / Si substrate, a 2D-BP deposition layer, and at least one BEP shell. The structural formula of the BEP in the BEP shell is as follows: The BP-BEP heterojunction material of the present invention can be used as a channel material to fabricate field-effect transistors (FETs). The coating of BEP can improve the on / off ratio of the BP FET. The increase in the on / off ratio can further reduce its power consumption, improve its signal response speed and enhance its noise immunity, thus having industrial applicability.
Claims
1. A black phosphorus-boron ester polymer heterojunction material, characterized in that: From the inside out, it includes a SiO2 / Si substrate, a 2D-BP deposition layer, and at least one BEP shell, wherein, The structural formula of BEP in the BEP shell is:
2. The method for preparing a black phosphorus-boron ester polymer heterojunction material as described in claim 1, characterized in that: Includes the following steps: (1) 2D-BP is deposited on the surface of a SiO2 / Si substrate to form the 2D-BP deposition layer; (2) At room temperature, the material obtained in step (1) is soaked in anhydrous ethanol, then TC solution is added and allowed to stand for reaction, and then TB solution is added and allowed to stand for reaction to obtain the product. The structural formula of TC in the above TC solution is: The structural formula of TB in the above TB solution is:
3. The preparation method according to claim 2, characterized in that: The synthetic route of TC is as follows:
4. The preparation method according to claim 2, characterized in that: The synthetic route for TB is as follows:
5. The preparation method according to any one of claims 1 to 4, characterized in that: Step (1) is as follows: 2D-BP dispersion is dropped onto the SiO2 / Si substrate, and after the solvent evaporates, it is vacuum annealed at 180°C for 30 min.
6. The preparation method according to claim 5, characterized in that: In step (2), the time for standing reaction after adding TC solution is 0.5-1h.
7. The preparation method according to claim 5, characterized in that: In step (2), the time for standing reaction after adding TB solution is 10-14 hours.
8. The preparation method according to claim 5, characterized in that: In step (2), the standing reaction time after adding TC solution is 0.5-1h, and the standing reaction time after adding TB solution is 10-14h.
9. The use of the black phosphorus-boron ester polymer heterojunction material as described in claim 1 in the fabrication of field-effect transistors.
10. A field-effect transistor, characterized in that: The material of its channel includes the black phosphorus-boron ester polymer heterojunction material as described in claim 1.