Novel single-molecule break junction technology measuring device with wide-angle open space

Abstract

The invention discloses a novel single molecule cleavage technology measuring device with a wide-angle open space, a needle tip moving part is fixed on an optical platform through a displacement table, a transmission mechanism is arranged on the displacement table, a displacement sliding block is connected to the transmission mechanism, and a right-angle switching structural member is fixedly mounted on the front surface of the displacement sliding block; a piezoelectric ceramic is arranged below the far end of the right-angle switching structural member, the piezoelectric ceramic is sleeved with a shielding ring, a needle cylinder is fixedly installed at the bottom of the piezoelectric ceramic, and the needle cylinder is used for fixing a needle tip and leading out a needle tip signal; and a chassis is arranged below the front side of the displacement table. The objective of the invention is to make architecture improvement on a split junction technology based on a scanning tunneling microscope, so that the split junction technology has an open space for accommodating incidence and measurement of light rays, the stability of electrical measurement of an instrument is not affected, and the instrument has the capabilities of optical regulation and control and spectroscopic measurement while being rapid in operation and convenient in sample preparation.

Description

Technical Field

[0001] The invention relates to the technical field of single molecule electronics measurement, and in particular to a novel single molecule split junction technology measurement device with a large-angle open space. Background Art

[0002] After decades of development, the measurement technology of molecular electronics has a mature research system for testing the electrical properties of molecules, including conductivity, tunneling mechanism, etc. However, there is currently a lack of effective research methods for the coupling, connection configuration and direction of molecules and electrodes, and the conformational changes of molecules between electrodes. The use of spectroscopy technology can effectively supplement this information. For example, Raman spectroscopy can detect the vibration of chemical bonds in molecules, making it easier for researchers to understand the molecular conformation between electrodes.

[0003] The closest existing implementation is:

[0004] There have been some works that combine spectral measurements with molecular electronics measurement instruments. These works are generally based on the instrument architecture of mechanically controlled split junction technology. The mechanical displacement part of this architecture is at the bottom of the sample, and the space above is kept open, so the upper space can easily introduce spectral measurement components. However, the sample preparation process of mechanically controlled split junction technology is cumbersome, and the leads of the sample disk are easily damaged. Limited by metal fatigue, the stability and repeatability of the substrate will also decay over time. At the same time, mechanically controlled split junction technology controls the spacing between electrodes through the elastic deformation of the metal substrate, and can only be fine-tuned on the z-axis, so optical imaging is not possible, and it can only be used for electrical measurements.

[0005] Another common molecular electronics measurement instrument is the split junction technology based on the scanning tunneling microscope. Compared with the mechanically controllable split junction technology, its tip-base configuration is derived from the mature scanning tunneling microscope, which has considerable advantages in sample preparation speed and sample stability. However, the samples of the scanning tunneling microscope are generally in a closed or semi-closed environment, and there is no open space above the sample, which is not conducive to the introduction of light and the arrangement of measurement devices.

[0006] In summary, the shortcomings of the prior art are:

[0007] Although the instrument architecture of mechanically controllable cracking technology is conducive to light incidence and measurement, the sample preparation operation is complicated and has a high failure rate. During the experiment, since the metal substrate needs to be pushed repeatedly to deform and rebound thousands of times, it is easy to cause problems such as decreased experimental stability and liquid pool leakage due to metal fatigue. In addition, mechanically controllable cracking technology can only be precisely adjusted in the z direction, and there is no way to adjust the xy direction. Therefore, it only has the ability to perform electrical measurements in a very small range, and does not have the ability to image and switch fields of view.

[0008] Although the splitting technology based on scanning tunneling microscopy is more convenient and faster in sample preparation and experimental operation, the design of its sample plate and displacement device does not leave any open space, and there is no space for light to be incident and measured.

[0009] Therefore, it is urgent to design a new single-molecule splitting technology measurement device with a large-angle open space to solve the above problems. Summary of the invention

[0010] The purpose of the present invention is to provide a novel single molecule cleavage technique measuring device with a large angle open space to solve the above-mentioned deficiencies in the prior art.

[0011] In order to achieve the above object, the present invention provides the following technical solutions:

[0012] A novel single molecule cleavage technique measuring device with a large-angle open space comprises a displacement stage, a transmission mechanism is arranged on the displacement stage, and a displacement slider is connected to the transmission mechanism, and a right-angle transfer structure is fixedly installed on the front of the displacement slider;

[0013] A piezoelectric ceramic is arranged below the distal end of the right-angle transition structure, and a syringe is fixedly installed at the bottom of the piezoelectric ceramic, a needle tip is arranged at the bottom of the syringe, and a shielding ring is sleeved on the outside of the piezoelectric ceramic;

[0014] A chassis is provided at the lower front side of the displacement stage, a 3Pin interface is provided at one side of the top of the chassis, a mounting groove is provided on the outer wall of the top of the chassis, a gold sheet is provided inside the mounting groove, a cover plate fixed on the outer wall of the top of the chassis is provided above the gold sheet, a shallow groove is provided on the outer wall of the top of the cover plate, a Teflon liquid pool is inserted into the shallow groove, an action slot is provided on the outer wall of one side of the top of the chassis, a Teflon insulating wall is inserted into the slot, and a spring contact point is inserted into the Teflon insulating wall.

[0015] Furthermore, the right-angle transition structure is a right-angle triangle structure, and the needle tip and the displacement stage form a dislocation structure through the right-angle transition structure.

[0016] Furthermore, the 3Pin interface includes a 3Pin interface plug-in block and a 3Pin interface female socket, the 3Pin interface female socket is fixed on the outer wall on one side of the top of the chassis, the 3Pin interface plug-in block is plugged into the inside of the 3Pin interface female socket, a plurality of contact heads are arranged inside the 3Pin interface female socket, and a fixing buckle is arranged on the top of the 3Pin interface plug-in block.

[0017] Furthermore, the Teflon liquid pool is made of Teflon material and has good acid and alkali resistance and heat resistance.

[0018] Furthermore, the substrate of the gold sheet is obtained by plating 111 layers of gold on a 3cm*3cm mica sheet.

[0019] Furthermore, the chassis fixes the sample area on the optical platform, and the chassis is at least used to assist in fixing and supporting the gold sheet and the substrate.

[0020] Furthermore, a terminal is provided on the outer wall of one side of the top of the chassis, and the terminal is electrically connected to the 3Pin interface, a signal line is fixedly connected to one side of the spring contact point, and a connecting ring installed on the terminal is fixedly provided at the far end of the signal line.

[0021] In the above technical scheme, the present invention provides a new single-molecule split junction technology measurement device with a large-angle open space. The purpose of the present invention is to make an architectural improvement to the split junction technology based on a scanning tunneling microscope so that it has an open space to accommodate the incidence and measurement of light without affecting the stability of the electrical measurement of the instrument itself, so that the instrument has the ability to perform spectroscopic measurements while being fast to operate and convenient to prepare samples. Compared with the traditional instrument architecture, this scheme provides a more open space to accommodate the optical path, thereby conveniently realizing the combination of molecular electronics measurement and spectroscopic measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. The drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0023] Figure 1 A schematic diagram of the structure of a displacement stage provided in an embodiment of a novel single-molecule cleavage technique measurement device with a large-angle open space of the present invention.

[0024] Figure 2 A schematic diagram of the structure of installing a spectroscopy measurement lens and a chassis is provided for an embodiment of a novel single-molecule cleavage technology measurement device with a large-angle open space of the present invention.

[0025] Figure 3 A top view of a displacement slider, a right-angle transition structure and a chassis structure provided for an embodiment of a novel single-molecule cleavage technology measurement device with a large-angle open space of the present invention.

[0026] Figure 4 A schematic diagram of the structure on the chassis provided for an embodiment of a novel single-molecule cleavage technique measurement device with a large-angle open space of the present invention.

[0027] Figure 5An exploded view of the structure on the chassis provided for an embodiment of a novel single-molecule cleavage technique measurement device with a large-angle open space of the present invention.

[0028] Description of reference numerals:

[0029] 1. Displacement stage; 2. Motor mounting seat; 3. Support plate; 4. Bearing seat; 5. Screw; 6. Stepper motor; 7. Screw nut; 8. Displacement slider; 9. Right-angle adapter structure; 10. Piezoelectric ceramics; 11. Shielding ring; 12. Syringe; 13. Needle tip; 14. Spectroscopic measurement lens for analog setting; 15. Chassis; 16. 3Pin interface plug-in block; 17. 3Pin interface female seat; 18. Contact head; 19. Fixing buckle; 20. Terminal; 21. Mounting groove; 22. Gold sheet; 23. Cover plate; 24. Shallow groove; 25. Teflon liquid pool; 26. Connecting ring; 27. Signal line; 28. Spring contact point; 29. ​​Teflon insulation wall. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] like Figure 1-5 As shown, a novel single molecule fission junction measurement device with a large-angle open space provided by an embodiment of the present invention comprises a displacement stage 1, a transmission mechanism is arranged on the displacement stage 1, and a displacement slider 8 is connected to the transmission mechanism, and a right-angle transition structure 9 is fixedly installed on the front of the displacement slider 8; a piezoelectric ceramic 10 is arranged below the far end of the right-angle transition structure 9, and a syringe 12 is fixedly installed at the bottom of the piezoelectric ceramic 10, a needle tip 13 is arranged at the bottom of the syringe 12, and a shielding ring 11 is sleeved on the outside of the piezoelectric ceramic 10; a shielding ring 11 is arranged at the bottom of the front side of the displacement stage 1 A chassis 15 is provided, a 3Pin interface is arranged on one side of the top of the chassis 15, a mounting groove 21 is arranged on the outer wall of the top of the chassis 15, and a gold sheet 22 is arranged inside the mounting groove 21, a cover plate 23 fixed on the outer wall of the top of the chassis 15 is arranged above the gold sheet 22, a shallow groove 24 is arranged on the outer wall of the top of the cover plate 23, and a Teflon liquid pool 25 is inserted into the shallow groove 24, a slot is arranged on the outer wall of one side of the top of the chassis 15, and a Teflon insulating wall 29 is inserted into the slot, and a spring contact point 28 is inserted into the Teflon insulating wall 29.

[0032] In this embodiment, a displacement stage 1 is provided on which a transmission mechanism is provided. By starting a stepping motor 6, a displacement slider 8 can be driven to move up and down with micron-level precision, thereby driving the needle tip 13 to move up and down.

[0033] In this embodiment, a displacement slider 8 is connected to the transmission mechanism, and a right-angle transition structure 9 is fixedly installed on the front of the displacement slider 8;

[0034] Specifically, the front section of the right-angle transition structure 9 is an isosceles triangle structure, which has stability while opening up as much space as possible. The needle tip 13 and the translation stage 1 form a staggered structure through the right-angle transition structure 9, which provides enough open space in the sample area to facilitate combination with spectroscopy research.

[0035] In this embodiment, a piezoelectric ceramic 10 is arranged below the far end of the right-angle transition structure 9. The piezoelectric ceramic 10 has high precision and repeatable positioning, and performs well in molecular electronics measurement experiments. The piezoelectric ceramic 10 is used to provide precise control of the z-axis in single-molecule electronics. The control accuracy can reach the picometer level, and the maximum stroke is at the micron level. Therefore, it can work with the stepper motor 6 and the displacement slider 8, and a syringe 12 is fixedly installed at the bottom of the piezoelectric ceramic 10. A needle tip 13 is arranged at the bottom of the syringe 12. The syringe 12 plays a role in fixing the needle tip 13 and leading the needle tip 13 signal through the coaxial line. A shielding ring 11 is sleeved on the outside of the piezoelectric ceramic 10. The piezoelectric ceramic 10 needs to input an external voltage signal. The noise and start and stop of the input signal, as well as the leakage of the piezoelectric ceramic 10 itself, have a direct impact on the needle tip 13 part that will be connected. Therefore, this design adds a copper shielding ring 11 at the connection between the needle tip 13 and the piezoelectric ceramic 10 to shield the noise of the mechanical moving part, and the shielding ring 11 is grounded through a cable;

[0036] In this embodiment, a chassis 15 is disposed at the lower front side of the translation stage 1;

[0037] Specifically, the base plate 15 fixes the sample area on the optical platform, and the base plate 15 is used to fix and support the gold sheet 22 substrate.

[0038] In this embodiment, a 3-pin interface is provided on one side of the top of the chassis 15. The 3-pin interface integrates the signal line of the spring contact point 28 and the reference electrode and counter electrode signal lines required for electrochemistry into one terminal, which facilitates the installation of the sample tray;

[0039] Specifically, the 3Pin interface includes a 3Pin interface plug-in block 16 and a 3Pin interface female socket 17. The 3Pin interface female socket 17 is fixed on the outer wall of one side of the top of the chassis 15. The 3Pin interface plug-in block 16 is plugged into the inside of the 3Pin interface female socket 17. The inside of the 3Pin interface female socket 17 is provided with a plurality of contact heads 18. A fixing buckle 19 is provided on the top of the 3Pin interface plug-in block 16.

[0040] Specifically, a terminal 20 is provided on the outer wall of one side of the top of the chassis 15, and the terminal 20 is electrically connected to the 3Pin interface, a signal line 27 is fixedly connected to one side of the spring contact point 28, and a connecting ring 26 installed on the terminal 20 is fixedly provided at the far end of the signal line 27.

[0041] In this embodiment, a mounting groove 21 is provided on the outer wall of the top of the chassis 15, and a gold sheet 22 is provided inside the mounting groove 21. A cover plate 23 fixed to the outer wall of the top of the chassis 15 is provided above the gold sheet 22. The function of the cover plate 23 is to press the Teflon liquid pool 25 and the gold sheet 22 downward to fix the sample;

[0042] Specifically, the base of the gold sheet 22 is obtained by plating 111 layers of gold on a 3cm*3cm mica sheet. The gold sheet 22 is used as an electrode for applying bias voltage in the experiment and also needs to carry the sample.

[0043] In this embodiment, a shallow groove 24 is provided on the outer wall of the top of the cover plate 23, and a Teflon liquid pool 25 is inserted into the shallow groove 24;

[0044] Specifically, the Teflon liquid pool 25 is made of Teflon material, has good acid and alkali resistance and heat resistance, and has sufficient toughness to fix the gold sheet 22 and contain the solution to be tested.

[0045] In this embodiment, a slot is provided on the outer wall on one side of the top of the chassis 15, and a Teflon insulating wall 29 is inserted into the slot. The function of the Teflon insulating wall 29 is to use the toughness of the Teflon material to fill the gap between the slot on the cover plate 23 and the spring contact point 28, thereby firmly fixing the spring contact point 28, and also preventing the cover plate 23 and the spring contact point 28 from directly contacting each other, thereby avoiding the bias voltage signal from being grounded. The spring contact point 28 is inserted into the Teflon insulating wall 29, and one end of the spring contact point 28 is in contact with the gold sheet 22 for inputting the bias voltage signal. The spring contact point 28 relies on slight elasticity to ensure good contact with the gold sheet 22.

[0046] In this embodiment, a spectroscopy measurement lens 14 is simulated on one side above the chassis 15. The open angle between the chassis 15 and the right-angle adapter structure 9 is measured, and it can have a light introduction / extraction angle of at least φ>80 degrees and θ>145 degrees at the needle tip.

[0047] Working principle:

[0048] Sample assembly process: First, anneal the gold sheet 22 and put it into the installation slot 21 reserved in the chassis 15, fix the Teflon liquid pool 25 on the cover 23, and then press it on the gold sheet 22 together with the cover 23. The two ends of the cover 23 are fixed to the chassis 15 and pressed tightly by M3 screws. After ensuring that the Teflon liquid pool 25 does not leak, the liquid sample can be added. Then, insert the spring contact point 28 into the Teflon insulating wall 29, and then insert it into the slot reserved in the cover 23. After ensuring that the spring contact point 28 is in good contact with the gold sheet 22, connect the terminal of the spring contact point 28 to the terminal 20 through the signal line 27 and the connecting ring 26, and then connect the terminal 20 to the 3Pin interface through the signal line. The 3Pin interface is connected to the controller, and then the chassis 15 can be fixed on the optical platform through M6 screws and copper pillars.

[0049] Needle tip assembly process: insert the prepared needle tip 13 into the syringe 12 and fix it, then connect the syringe 12 part to the bottom end of the piezoelectric ceramic 10, and put the shielding ring 11 on the outside of the piezoelectric ceramic 10, and connect the connecting wire of the needle tip 13 to the current amplifier to detect the tunnel current signal of the needle tip 13.

[0050] After the sample and the needle tip 13 are assembled, the automated program uses the needle tip tunnel current as a basis for judgment. Through the stepper motor 6 moving on the displacement stage 1, the stepper motor 6 can drive the screw 5 to rotate, and drive the screw nut 7 and the displacement slider 8 to move, and roughly adjust the distance between the needle tip 13 and the gold sheet 22. The piezoelectric ceramic 10 fine-tunes the distance, so that the needle tip 13 is close to and away from the chassis 15, and repeats this process thousands of times, while recording the tunnel current information from the needle tip 13 to the chassis 15 for subsequent analysis. When a molecular signal is captured, the light of the spectroscopy measurement lens 14 can be focused on the needle tip 13 area to capture the spectral signal from the molecule.

[0051] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A novel single-molecule cleavage technique measuring device with a large-angle open space, comprising a displacement stage (1), characterized in that: The displacement platform (1) is provided with a transmission mechanism, and a displacement slider (8) is connected to the transmission mechanism, and a right-angle transfer structure (9) is fixedly mounted on the front of the displacement slider (8); A piezoelectric ceramic (10) is arranged below the distal end of the right-angle transition structural member (9), a syringe (12) is fixedly mounted at the bottom of the piezoelectric ceramic (10), a needle tip (13) is arranged at the bottom of the syringe (12), and a shielding ring (11) is sleeved on the outside of the piezoelectric ceramic (10); A chassis (15) is arranged at the lower front side of the displacement platform (1), a 3-pin interface is arranged at one side of the top of the chassis (15), a mounting groove (21) is arranged on the outer wall of the top of the chassis (15), a gold sheet (22) can be installed in the mounting groove (21), a cover plate (23) fixed on the outer wall of the top of the chassis (15) is arranged above the gold sheet (22), a shallow groove (24) is arranged on the outer wall of the top of the cover plate (23), and a Teflon liquid pool (25) is fixed in the shallow groove (24), a slot is provided on the outer wall of one side of the top of the chassis (15), a Teflon insulating wall (29) is inserted into the slot, and a spring contact point (28) is inserted into the Teflon insulating wall (29).

2. A novel single molecule cleavage technique measuring device with a large angle open space according to claim 1, characterized in that: The upper side of the chassis (15) has an open space structure, on which a spectroscopy measurement lens (14) can be arranged, and a light introduction / extraction angle of at least φ>80 degrees and θ>145 degrees can be provided at the needle tip.

3. A novel single molecule splitting technique measuring device with a large angle open space according to claim 1, characterized in that: The right-angle transition structural member (9) is a right-angled triangle structure, and the needle tip (13) and the displacement platform (1) form a dislocation structure through the right-angle transition structural member (9).

4. A novel single molecule splitting technique measuring device with a large angle open space according to claim 1, characterized in that: The 3Pin interface comprises a 3Pin interface plug-in block (16) and a 3Pin interface female socket (17); the 3Pin interface female socket (17) is fixed on the outer wall of one side of the top of the chassis (15); the 3Pin interface plug-in block (16) is plugged into the interior of the 3Pin interface female socket (17); a plurality of contact heads (18) are arranged inside the 3Pin interface female socket (17); and a fixing buckle (19) is arranged on the top of the 3Pin interface plug-in block (16).

5. A novel single molecule cleavage technique measuring device with a large angle open space according to claim 1, characterized in that: The Teflon liquid pool (25) is made of Teflon material and has good acid and alkali resistance and heat resistance.

6. A novel single molecule cleavage technique measuring device with a large angle open space according to claim 1, characterized in that: The substrate of the gold sheet (22) is obtained by plating 111 layers of gold on a 3cm*3cm mica sheet.

7. A novel single molecule cleavage technique measuring device with a large angle open space according to claim 6, characterized in that: The base plate (15) fixes the sample area on the optical platform, and the base plate (15) is used to assist in fixing and supporting the gold sheet (22) substrate.

8. A novel single molecule cleavage technique measuring device with a large angle open space according to claim 1, characterized in that: A terminal (20) is provided on the outer wall of one side of the top of the chassis (15), and the terminal (20) is electrically connected to the 3Pin interface. A signal line (27) is fixedly connected to one side of the spring contact point (28), and a connecting ring (26) installed on the terminal (20) is fixedly provided at the far end of the signal line (27).

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