Atomic-scale construction method of fixed-axis molecular rotor on surface of semiconductor substrate and array of fixed-axis molecular rotor

Abstract

The invention discloses a semiconductor substrate surface fixed-axis molecular rotor and an atomic-scale construction method of an array thereof, and the method comprises the steps: carrying out the evaporation of metal atoms and phthalocyanine molecules on the surface of a semiconductor substrate through an ultrahigh vacuum thermal evaporation method; performing transverse manipulation on phthalocyanine molecules by using a scanning tunneling microscope, placing the phthalocyanine molecules on the metal atoms adsorbed on the surface, and longitudinally manipulating the metal atoms to be placed on the phthalocyanine molecules by using the scanning tunneling microscope to obtain a metal atom-phthalocyanine molecule-metal atom fixed-axis molecular rotor composite structure; local potential is regulated and controlled by applying grid voltage, and rotation and regulation and control of the molecular rotor are achieved. According to the method, atomic-scale accurate anchoring of the molecular rotor composite structure is achieved, and rotor array arrangement is achieved; the local potential is regulated and controlled through the grid voltage of the pre-embedded electrode, so that the regulation and control of the rotating speed are realized; the molecular rotor array is precisely designed through precision machining with single atoms and molecules as elements, and the problem that the molecular structure cannot be repositioned and arranged is solved.

Description

Technical Field

[0001] The present invention belongs to the field of atomic-level manufacturing of molecular machines, and relates to a method for constructing a fixed-axis molecular rotor and an array thereof with atomic-level precision construction having a controllable rotation function on the surface of a semiconductor substrate. Background Art

[0002] Artificial molecular rotors / motors are important components of molecular machines and have broad application prospects in storage, smart materials, medicine, catalysis and other fields. At present, the synthesis of the first batch of molecular machines has been achieved through chemical synthesis methods in solution. However, on the solid surface, due to the limitations of the substrate and chemical design, the precise construction and manipulation of molecular machines become more complicated. For molecular rotors, high-level control of the rotation axis and self-assembly are key factors in integrating molecular rotors into complex molecular machines.

[0003] At present, this type of molecular rotor is mainly prepared by organic synthesis methods in solution, and the rotor is formed on the substrate surface by thermodynamic molecular self-assembly. For example, Liang Wenjuan et al. of Shanxi Datong University disclosed a method for preparing a molecular rotor in patent CN202110736882.8 "3'-acetyl-[2,2'-bithiophene]-3-formaldehyde derivative and preparation method and application", and Zhen Shijie et al. of Guilin University of Technology disclosed a method for achieving molecular anchoring in patent CN202311703323.2 "A new type of spatial conjugated organic molecule based on hexaphenylbenzene anchoring group and its preparation and application". The disadvantage is that the synthetic product is accompanied by by-products, and it is impossible to achieve precise positioning anchoring and construction at the atomic level on the substrate surface. In addition, people have been able to achieve directional movement of simple metal atoms and molecules on metal surfaces through the tip of a scanning tunneling microscope. An Yang et al. from the Institute of Physics, Chinese Academy of Sciences, described the directional movement of CO molecules on the copper surface in patent CN202011524830.6 "A method and system for transporting atoms / molecules". The disadvantage is that it is impossible to achieve longitudinal assembly, so it is impossible to build a molecular structure with functions such as rotation. In order to achieve a molecular structure with a clear function, different strategies need to be adopted to design the molecular structure. Among them, limiting the lateral diffusion of molecules and a stable rotation axis are necessary conditions for achieving molecular rotation, while the weak adsorption of molecules and substrates is a prerequisite for repositioning molecules to form an array. At present, people can use substrate defects, molecular substrate bonding, etc. as the rotation axis, but the rotation axis is fixed and cannot be repositioned. Therefore, it is a challenge to simultaneously achieve fixed-axis rotation of molecules and precise construction of molecular rotor arrays.

[0004] In view of this, the present invention proposes an atomic-level construction method of a fixed-axis molecular rotor and an array thereof on the surface of a semiconductor substrate to solve the above problems. Summary of the invention

[0005] In order to solve the above-mentioned defects existing in the prior art, the purpose of the present invention is to provide an atomic-level construction method for fixed-axis molecular rotors and arrays thereof on the surface of semiconductor substrates. Based on single-atom / molecule manipulation technology, metal atoms and phthalocyanine molecules are artificially and controllably assembled, and with the help of natural metal vacancies on the surface of III-V semiconductor substrates, the fixed-axis molecular rotors are anchored, thereby realizing the atomic-level precise construction of fixed-axis molecular rotors and arrays thereof.

[0006] The present invention is achieved through the following technical solutions.

[0007] The present invention provides an atomic-level construction method of a fixed-axis molecular rotor on a semiconductor substrate surface and an array thereof, comprising:

[0008] The III-V semiconductor substrate is cleaved by ultra-high vacuum to obtain an atomic-level clean surface;

[0009] By ultra-high vacuum thermal evaporation method, metal atoms and phthalocyanine molecules are evaporated on the surface of semiconductor substrate respectively;

[0010] Scan the sample using a scanning tunneling microscope to obtain the surface morphology;

[0011] Identify the locations of metal atoms and phthalocyanine molecules adsorbed on the surface of the semiconductor substrate based on the surface topography;

[0012] The tip of a scanning tunneling microscope is used to laterally manipulate the phthalocyanine molecule, placing the phthalocyanine molecule on the metal atom adsorbed on the surface to form a metal atom-phthalocyanine molecule structure;

[0013] Using the tip of a scanning tunneling microscope to longitudinally manipulate another metal atom, another metal atom is placed on the phthalocyanine molecule to obtain a metal atom-phthalocyanine molecule-metal atom fixed-axis molecular rotor composite structure;

[0014] The molecular rotor is rotated and regulated by applying a gate voltage to control the local potential; and the molecular rotor signal output is achieved by providing a source and a drain at both ends of the molecular rotor.

[0015] Preferably, the Group III-V semiconductor includes InAs, GaAs, InSb or GaSb.

[0016] Preferably, the metal atom includes K, Na, Rb, Ga, In or Cs.

[0017] Preferably, the phthalocyanine molecule comprises a lanthanide bisphthalocyanine complex LnPC2, wherein Ln = La / Ce / Pr / Nd / Pm / Sm / Eu / Gd / Tb / Dy / Ho / Er / Tm / Yb / Lu.

[0018] Preferably, there are metal vacancies with natural reconstructed structures on the surface of the III-V semiconductor, and the grown metal atoms are mainly attached to the metal vacancies of the III-V semiconductor.

[0019] Preferably, the scanning tunneling microscope and its needle tip work in an ultra-high vacuum environment with a pressure not higher than 10 -7 Pa; sample temperature is not higher than 4.5K.

[0020] Preferably, for lateral manipulation of phthalocyanine molecules, the sample is biased at -0.5 to -0.8 V, the tunneling current is 0.2 to 0.6 nA, and the needle tip moves from the top of the phthalocyanine molecule to the top of the metal atom to achieve lateral manipulation of the molecule.

[0021] Preferably, the metal atom is manipulated longitudinally, a bias voltage of +1V to +1.3V is used to lift the metal atom, the needle tip is placed above the phthalocyanine molecule, and a bias voltage of -1V to -1.3V is used to release the metal atom.

[0022] Preferably, the gate voltage is between ±0.8V and ±1.5V.

[0023] Preferably, the bottom gate uses a gold electrode and a silicon oxide layer, and the source and drain use gold electrodes, which are located on the surface of the III-V semiconductor and close to both sides of the molecular rotor.

[0024] The present invention adopts the above technical solution, which has the following beneficial effects:

[0025] 1. The fixed-axis molecular rotor of the present invention has a simple structure and involves only a single molecule and two atoms. The molecular rotor can be precisely anchored by the diffusion barrier of the natural metal vacancies of the substrate to the metal atoms. The rotation of the fixed-axis molecular rotor can be controlled and adjusted by using the pre-buried gate voltage.

[0026] 2. The present invention selects to realize the fixed-axis molecular rotor assembly on the III-V semiconductor substrate, which is compatible with semiconductor technology, has higher application value, and is conducive to the integration of functional devices.

[0027] 3. The present invention deposits metal atoms and phthalocyanine molecules by evaporation, breaking through the traditional chemical synthesis method. Based on the atomic and molecular manipulation of the scanning tunneling microscope, the precise assembly and reversible disassembly of molecular rotors at the atomic level can be achieved, and the molecular rotors can be precisely positioned to design any molecular rotor array, which has a larger controllable space and has important advantages in the manufacture of molecular rotors and molecular machines, and has important research value in the fields of molecular switches, molecular storage, and molecular carriers. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1 Schematic diagram of the three-dimensional structure of a fixed-axis molecular rotor;

[0030] Figure 2 (a)-(i) is a manufacturing process flow of a fixed-axis molecular rotor and array;

[0031] Figure 3 Scanning tunneling microscope topography of In atoms and LaPc2 molecules on an InAs substrate for implementation example 1;

[0032] Figure 4 Scanning tunneling microscope morphology of the In-LaPc2 composite structure on an InAs substrate for implementation example 1;

[0033] Figure 5 Scanning tunneling microscopy image of an In-LaPc2-In composite structure assembled on an InAs substrate for implementation example 1;

[0034] Figure 6 Output It image of applying gate voltage to In-LaPc2-In molecular rotor on InAs substrate for implementation example 1;

[0035] Figure 7 Scanning tunneling microscopy image of three LaPc2 molecular anchor arrays implemented on an InAs substrate for implementation example 1. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The exemplary embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0037] The embodiment of the present invention provides an atomic-level construction method of a fixed-axis molecular rotor and an array thereof on a semiconductor substrate surface, and the specific steps are as follows:

[0038] Step 1, selecting a III-V semiconductor substrate having an atomically clean surface obtained by ultra-high vacuum cleavage, wherein the III-V semiconductor includes InAs, GaAs, InSb or GaSb; a bottom gate is provided under the substrate, as shown in FIG2(a).

[0039] Step 2: Deposit metal atoms on the surface of the semiconductor substrate by ultra-high vacuum thermal evaporation. The metal atoms include K, Na, Rb, Ga, In or Cs. There are metal vacancies with natural reconstructed structures on the surface of III-V semiconductors. The metal atoms are distributed on the top of the metal vacancies on the semiconductor substrate. The metal atoms and the natural metal vacancies on the surface of III-V semiconductors are physically adsorbed, but have a high diffusion barrier and are not easily translated by perturbations. See Figure 2(b).

[0040] Step 3, continue to evaporate phthalocyanine molecules on the surface of the semiconductor substrate by ultra-high vacuum thermal evaporation method. The phthalocyanine molecules are randomly distributed on the surface of the III-V semiconductor and are unstable and easily move in a translational manner due to perturbations, as shown in Figure 2(c).

[0041] Phthalocyanine molecules include the lanthanide bisphthalocyanine complex LnPC2, where Ln = La / Ce / Pr / Nd / Pm / Sm / Eu / Gd / Tb / Dy / Ho / Er / Tm / Yb / Lu.

[0042] Step 4: Scan the sample using a tungsten tip of a scanning tunneling microscope. The working environment of the scanning tunneling microscope and its tip is an ultra-high vacuum: the pressure is no higher than 10 -7 Pa; the sample temperature is not higher than 4.5 K. Scan to obtain the surface morphology map and obtain the positions of metal atoms and phthalocyanine molecules on the surface of the semiconductor substrate.

[0043] Step 5, use the tungsten tip electrochemically etched by the scanning tunneling microscope to laterally manipulate the phthalocyanine molecule. The tip is grounded, a bias of -0.5 to -0.8 V is applied to the semiconductor substrate, and the tunneling current is 0.2 to 0.6 nA. Move the tungsten tip of the scanning tunneling microscope to the top of the phthalocyanine molecule, as shown in Figure 2(d).

[0044] Step 6: Move the tip of the scanning tunneling microscope from the top of the phthalocyanine molecule to the top of the metal atom to achieve lateral manipulation of the molecule. Placing the phthalocyanine molecule on the metal atom adsorbed on the surface for assembly will anchor the phthalocyanine molecule with atomic-level positioning accuracy, forming a metal atom-phthalocyanine molecule structure, as shown in Figure 2(e).

[0045] Step 7, use the scanning tunneling microscope tip to longitudinally manipulate another metal atom, with the tip placed above the metal atom, and apply a bias of +1V to +1.3V to the semiconductor substrate to lift the metal atom, as shown in Figure 2(f).

[0046] Step 8, move the scanning tunneling microscope tip to above the phthalocyanine molecule, apply a bias voltage of -1V to -1.3V to the semiconductor substrate to release the metal atom, and place another metal atom on the phthalocyanine molecule to obtain a metal atom-phthalocyanine molecule-metal atom fixed-axis molecular rotor, as shown in Figure 2(g).

[0047] The prepared metal atom-phthalocyanine molecule-metal atom composite structure can be reversibly disassembled.

[0048] Step 9, the local potential is regulated by applying a gate voltage of ±0.8V to ±1.5V through the bottom gate of the semiconductor substrate. Under the gate voltage, the fixed-axis molecular rotor can be controlled to start and stop, and the rotation of different frequencies can be regulated to achieve the rotation and regulation of the fixed-axis molecular rotor. A source and a drain are provided at both ends of the molecular rotor to achieve the molecular rotor signal output, as shown in Figure 2(h).

[0049] The source and drain electrodes are made of gold electrodes, located on the surface of the III-V semiconductor, close to both sides of the molecular rotor. The bottom gate is made of gold electrodes and silicon oxide layer. The three-dimensional structure of the fixed-axis molecular rotor is shown in Figure 1 .

[0050] Step 10, repeat the above steps 3-8 to realize the assembly of multiple fixed-axis molecular rotor arrays, as shown in FIG2(i).

[0051] The preparation of the fixed-axis molecular rotor and its array of the present invention is further illustrated below through different embodiments.

[0052] Example 1

[0053] 1) A III-V semiconductor substrate having an atomic-level clean surface obtained by ultra-high vacuum cleavage is selected as InAs, and a bottom gate is provided under the substrate.

[0054] 2) Metal atoms In are evaporated on the surface of the semiconductor substrate by an ultra-high vacuum thermal evaporation method, and the In atoms are distributed on the top of the metal vacancies on the InAs substrate.

[0055] 3) Continue to evaporate phthalocyanine molecules LaPc2 on the surface of the semiconductor substrate by ultra-high vacuum thermal evaporation method, and the LaPc2 molecules are randomly distributed on the surface of the InAs substrate.

[0056] 4) Scan the sample with a tungsten tip in a scanning tunneling microscope, ultra-high vacuum: pressure no higher than 10 -7 Pa; the sample temperature is not higher than 4.5K. The surface morphology is obtained, and the positions of In atoms and LaPc2 molecules on the surface of the InAs substrate are obtained. Figure 3 .

[0057] 5) Use the tip of a scanning tunneling microscope to laterally manipulate the phthalocyanine molecule. The tip is grounded, a -0.5V bias is applied to the InAs substrate, the tunneling current is 0.2nA, and the tungsten tip of the scanning tunneling microscope is placed on the top of the LaPc2 molecule.

[0058] 6) Move the tip of the scanning tunneling microscope from the top of the LaPc2 molecule to the top of the In atom to achieve lateral manipulation of the molecule. Place the LaPc2 molecule on the surface adsorbed In atoms for assembly to form an In-LaPc2 composite structure, see Figure 4 .

[0059] 7) Use the tip of a scanning tunneling microscope to longitudinally manipulate another In atom, with the tip placed above the metal atom, and apply a +1.2V bias to the InAs substrate to lift the In atom.

[0060] 8) Move the tip of the scanning tunneling microscope to the top of the LaPc2 molecule, apply a bias of -1.1V to the InAs substrate to release the In atom, and place another In atom on the LaPc2 molecule to obtain the In-LaPc2-In fixed-axis molecular rotor, see Figure 5 .

[0061] 9) Applying +0.8V gate voltage to the bottom gate of the semiconductor substrate to control the local potential, realize the rotation and control of the fixed axis molecular rotor in step 8. A source and a drain are provided at both ends of the molecular rotor to realize the molecular rotor It signal output, see Figure 6 .

[0062] 10) Repeat the above steps 3-8 for 3 times to realize the assembly of 3 In-LaPc2-In fixed axis molecular rotor arrays, see Figure 7 .

[0063] Example 2

[0064] 1) A III-V semiconductor substrate having an atomic-level clean surface obtained by ultra-high vacuum cleavage is selected as GaAs, and a bottom gate is provided under the substrate.

[0065] 2) Using an ultra-high vacuum thermal evaporation method, metal atoms Cs are evaporated on the surface of the semiconductor substrate, and the Cs atoms are distributed on the top of the metal vacancies on the GaAs substrate.

[0066] 3) Continue to evaporate phthalocyanine molecules DyPc2 on the surface of the semiconductor substrate by ultra-high vacuum thermal evaporation method, and the DyPc2 molecules are randomly distributed on the surface of the GaAs substrate.

[0067] 4) Scan the sample with a tungsten tip in a scanning tunneling microscope, ultra-high vacuum: pressure no higher than 10 -7 Pa; the sample temperature is not higher than 4.5 K. The surface morphology map is obtained to obtain the positions of Cs atoms and DyPc2 molecules on the surface of the GaAs substrate.

[0068] 5) Use the tip of a scanning tunneling microscope to manipulate the phthalocyanine molecule laterally. The tip is grounded, a -0.6V bias is applied to the GaAs substrate, the tunneling current is 0.3nA, and the tungsten tip of the scanning tunneling microscope is placed on the top of the DyPc2 molecule.

[0069] 6) Move the tip of the scanning tunneling microscope from the top of the DyPc2 molecule to the top of the Cs atom to achieve lateral manipulation of the molecule. Place the DyPc2 molecule on the surface adsorbed Cs atom for assembly to form a Cs-DyPc2 composite structure.

[0070] 7) Use the tip of a scanning tunneling microscope to longitudinally manipulate another Cs atom, with the tip placed above the metal atom, and apply a +1.3V bias to the GaAs substrate to lift the Cs atom.

[0071] 8) Move the tip of the scanning tunneling microscope to above the DyPc2 molecule, apply a -1.2V bias to the GaAs substrate to release the Cs atom, and place another Cs atom on the DyPc2 molecule to obtain a Cs-DyPc2-Cs fixed-axis molecular rotor.

[0072] 9) The local potential is regulated by applying a gate voltage of ±1.0V through the bottom gate of the semiconductor substrate to realize the rotation and regulation of the fixed-axis molecular rotor in step 8. A source and a drain are provided at both ends of the molecular rotor to realize the molecular rotor It signal output.

[0073] 10) Repeat the above steps 3-8 three times to assemble three Cs-DyPc2-Cs fixed-axis molecular rotor arrays.

[0074] Example 3

[0075] 1) A III-V semiconductor substrate having an atomic-level clean surface obtained by ultra-high vacuum cleavage is selected as InSb, and a bottom gate is provided under the substrate.

[0076] 2) Metal atoms Rb are evaporated on the surface of the semiconductor substrate by ultra-high vacuum thermal evaporation method, and the Rb atoms are distributed on the top of the metal vacancies on the InSb substrate.

[0077] 3) Continue to evaporate phthalocyanine molecules NdPc2 on the surface of the semiconductor substrate by ultra-high vacuum thermal evaporation method, and the NdPc2 molecules are randomly distributed on the surface of the InSb substrate.

[0078] 4) Scan the sample with a tungsten tip in a scanning tunneling microscope, ultra-high vacuum: pressure no higher than 10 -7 Pa; the sample temperature is not higher than 4.5 K. The surface morphology is obtained to obtain the positions of Rb atoms and NdPc2 molecules on the surface of the InSb substrate.

[0079] 5) Use the tip of a scanning tunneling microscope to manipulate the phthalocyanine molecule laterally. The tip is grounded, a -0.7V bias is applied to the InSb substrate, the tunneling current is 0.6nA, and the tungsten tip of the scanning tunneling microscope is placed on the top of the NdPc2 molecule.

[0080] 6) Move the tip of the scanning tunneling microscope from the top of the NdPc2 molecule to the top of the Rb atom to achieve lateral manipulation of the molecule. Place the NdPc2 molecule on the surface adsorbed Rb atoms for assembly to form a Rb-NdPc2 composite structure.

[0081] 7) Use the tip of a scanning tunneling microscope to longitudinally manipulate another Rb atom, with the tip placed above the metal atom, and apply a +1.1V bias to the InSb substrate to lift the Rb atom.

[0082] 8) Move the tip of the scanning tunneling microscope to above the NdPc2 molecule, apply a -1.0V bias to the InSb substrate to release the Rb atom, and place another Rb atom on the NdPc2 molecule to obtain the Rb-NdPc2-Rb fixed-axis molecular rotor.

[0083] 9) The local potential is regulated by applying a gate voltage of ±1.2V through the bottom gate of the semiconductor substrate to realize the rotation and regulation of the fixed-axis molecular rotor in step 8. A source and a drain are provided at both ends of the molecular rotor to realize the molecular rotor It signal output.

[0084] 10) Repeat the above steps 3-8 three times to assemble three Rb-NdPc2-Rb fixed-axis molecular rotor arrays.

[0085] Example 4

[0086] 1) A III-V semiconductor substrate having an atomic-level clean surface obtained by ultra-high vacuum cleavage is selected as GaSb, and a bottom gate is provided under the substrate.

[0087] 2) Metal atoms Na are evaporated on the surface of the semiconductor substrate by an ultra-high vacuum thermal evaporation method, and the Na atoms are distributed on the top of the metal vacancies on the GaSb substrate.

[0088] 3) Continue to evaporate phthalocyanine molecules GdPc2 on the surface of the semiconductor substrate by ultra-high vacuum thermal evaporation method, and the GdPc2 molecules are randomly distributed on the surface of the GaSb substrate.

[0089] 4) Scan the sample with a tungsten tip in a scanning tunneling microscope, ultra-high vacuum: pressure no higher than 10 -7 Pa; the sample temperature is not higher than 4.5 K. The surface morphology map is obtained to obtain the positions of Na atoms and GdPc2 molecules on the surface of the GaSb substrate.

[0090] 5) Use the tip of a scanning tunneling microscope to manipulate the phthalocyanine molecule laterally. The tip is grounded, a -0.8V bias is applied to the GaSb substrate, the tunneling current is 0.4nA, and the tungsten tip of the scanning tunneling microscope is placed on the top of the GdPc2 molecule.

[0091] 6) Move the tip of the scanning tunneling microscope from the top of the GdPc2 molecule to the top of the Na atom to achieve lateral manipulation of the molecule. Place the GdPc2 molecule on the surface adsorbed Na atoms for assembly to form a Na-GdPc2 composite structure.

[0092] 7) Use the tip of a scanning tunneling microscope to longitudinally manipulate another Na atom, with the tip placed above the metal atom, and apply a +1.3V bias to the GaSb substrate to lift the Na atom.

[0093] 8) Move the tip of the scanning tunneling microscope to above the GdPc2 molecule, apply a -1.2V bias to the GaSb substrate to release the Na atom, and place another Na atom on the GdPc2 molecule to obtain a Na-GdPc2-Na fixed-axis molecular rotor.

[0094] 9) The local potential is regulated by applying a gate voltage of ±1.3V through the bottom gate of the semiconductor substrate to realize the rotation and regulation of the fixed-axis molecular rotor in step 8. A source and a drain are provided at both ends of the molecular rotor to realize the molecular rotor It signal output.

[0095] 10) Repeat the above steps 3-8 three times to assemble three Na-GdPc2-Na fixed-axis molecular rotor arrays.

[0096] Example 5

[0097] 1) A III-V semiconductor substrate having an atomic-level clean surface obtained by ultra-high vacuum cleavage is selected as InAs, and a bottom gate is provided under the substrate.

[0098] 2) Metal atoms Ga are evaporated on the surface of the semiconductor substrate by an ultra-high vacuum thermal evaporation method, and the Ga atoms are distributed on the top of the metal vacancies on the InAs substrate.

[0099] 3) Continue to evaporate phthalocyanine molecules CePc2 on the surface of the semiconductor substrate by ultra-high vacuum thermal evaporation method, and the CePc2 molecules are randomly distributed on the surface of the InAs substrate.

[0100] 4) Scan the sample with a tungsten tip in a scanning tunneling microscope, ultra-high vacuum: pressure no higher than 10 -7 Pa; the sample temperature is not higher than 4.5 K. The surface morphology is obtained to obtain the positions of Ga atoms and CePc2 molecules on the surface of the InAs substrate.

[0101] 5) Use the tip of a scanning tunneling microscope to manipulate the phthalocyanine molecule laterally. The tip is grounded, a -0.6V bias is applied to the InAs substrate, the tunneling current is 0.5nA, and the tungsten tip of the scanning tunneling microscope is placed on the top of the CePc2 molecule.

[0102] 6) Move the tip of the scanning tunneling microscope from the top of the CePc2 molecule to the top of the Ga atom to achieve lateral manipulation of the molecule. Place the CePc2 molecule on the surface adsorbed Ga atoms for assembly to form a Ga-CePc2 composite structure.

[0103] 7) Use the tip of a scanning tunneling microscope to longitudinally manipulate another Ga atom, with the tip placed above the metal atom, and apply a +1V bias to the InAs substrate to lift the Ga atom.

[0104] 8) Move the tip of the scanning tunneling microscope to above the CePc2 molecule, apply a bias of -1.3 V to the InAs substrate to release the Ga atom, and place another Ga atom on the CePc2 molecule to obtain a Ga-CePc2-Ga fixed-axis molecular rotor.

[0105] 9) The local potential is regulated by applying a gate voltage of ±1.5V through the bottom gate of the semiconductor substrate to realize the rotation and regulation of the fixed-axis molecular rotor in step 8. A source and a drain are provided at both ends of the molecular rotor to realize the molecular rotor It signal output.

[0106] 10) Repeat the above steps 3-8 three times to assemble three Ga-CePc2-Ga fixed-axis molecular rotor arrays.

[0107] From the above embodiments, it can be seen that the method of the present invention utilizes the characteristic of high diffusion barrier of natural metal vacancies on the surface of III-V semiconductor substrates for physically adsorbing metal atoms to achieve precise atomic-level anchoring of molecular rotor composite structures; by realizing fixed-axis molecular rotor assembly on III-V semiconductor substrates, limiting the lateral diffusion of molecules and stable rotation axis, the fixed-axis rotation of molecules and the precise construction and arrangement of molecular rotor arrays are achieved, solving the problem that the molecular structure cannot be repositioned and arranged. The rotation speed can be regulated by regulating the local potential through the gate voltage of the pre-buried electrode. Through the atomic-level manufacturing strategy, precision processing with single atoms and molecules as primitives is achieved, which is compatible with semiconductor processes, and the molecular rotor array can be precisely designed, with a larger controllable space.

[0108] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present invention, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present invention.

Claims

1. A method for atomic-level construction of fixed-axis molecular rotors and arrays thereof on the surface of a semiconductor substrate, characterized in that: include: The III-V semiconductor substrate is cleaved by ultra-high vacuum to obtain an atomic-level clean surface; By ultra-high vacuum thermal evaporation method, metal atoms and phthalocyanine molecules are evaporated on the surface of semiconductor substrate respectively; Scan the sample using a scanning tunneling microscope to obtain the surface morphology; Identify the locations of metal atoms and phthalocyanine molecules adsorbed on the surface of the semiconductor substrate based on the surface topography; The tip of a scanning tunneling microscope is used to laterally manipulate the phthalocyanine molecule, placing the phthalocyanine molecule on the metal atom adsorbed on the surface to form a metal atom-phthalocyanine molecule structure; Using the tip of a scanning tunneling microscope to longitudinally manipulate another metal atom, another metal atom is placed on the phthalocyanine molecule to obtain a metal atom-phthalocyanine molecule-metal atom fixed-axis molecular rotor composite structure; The molecular rotor is rotated and regulated by applying a gate voltage to control the local potential; and the molecular rotor signal output is achieved by providing a source and a drain at both ends of the molecular rotor.

2. The atomic-level construction method of fixed-axis molecular rotors and arrays thereof on the surface of a semiconductor substrate according to claim 1, characterized in that: Group III-V semiconductors include InAs, GaAs, InSb or GaSb.

3. The atomic-level construction method of fixed-axis molecular rotors and arrays thereof on the surface of a semiconductor substrate according to claim 1, characterized in that: The metal atom includes K, Na, Rb, Ga, In or Cs.

4. The atomic-level construction method of fixed-axis molecular rotors and arrays thereof on the surface of a semiconductor substrate according to claim 1, characterized in that: Phthalocyanine molecules include the lanthanide bisphthalocyanine complex LnPC2, where Ln = La / Ce / Pr / Nd / Pm / Sm / Eu / Gd / Tb / Dy / Ho / Er / Tm / Yb / Lu.

5. The atomic-level construction method of fixed-axis molecular rotors and arrays thereof on the surface of a semiconductor substrate according to claim 1, characterized in that: There are metal vacancies with natural reconstructed structures on the surface of III-V semiconductors, and the growing metal atoms are mainly attached to the metal vacancies in III-V semiconductors.

6. The atomic-level construction method of fixed-axis molecular rotors and arrays thereof on the surface of a semiconductor substrate according to claim 1, characterized in that: The scanning tunneling microscope and its tip work in an ultra-high vacuum environment with a pressure no higher than 10 -7 Pa; sample temperature is not higher than 4.5K.

7. The atomic-level construction method of fixed-axis molecular rotors and arrays thereof on the surface of a semiconductor substrate according to claim 1, characterized in that: For lateral manipulation of phthalocyanine molecules, the sample was biased at -0.5 to -0.8 V, the tunneling current was 0.2 to 0.6 nA, and the needle tip moved from the top of the phthalocyanine molecule to the top of the metal atom to achieve lateral manipulation of the molecule.

8. The atomic-level construction method of fixed-axis molecular rotors and arrays thereof on the surface of a semiconductor substrate according to claim 1, characterized in that: The metal atom is manipulated vertically, a bias voltage of +1V to +1.3V is used to lift the metal atom, the needle tip is placed above the phthalocyanine molecule, and a bias voltage of -1V to -1.3V is used to release the metal atom.

9. The atomic-level construction method of fixed-axis molecular rotors and arrays thereof on the surface of a semiconductor substrate according to claim 1, characterized in that: The gate voltage is between ±0.8V and ±1.5V.

10. The atomic-level construction method of fixed-axis molecular rotors and arrays thereof on the surface of a semiconductor substrate according to claim 1, characterized in that: The bottom gate uses a gold electrode and a silicon oxide layer, and the source and drain use gold electrodes, which are located on the surface of the III-V semiconductor, close to both sides of the molecular rotor.

Images