JP2009032897A - Method of manufacturing functional molecular element, method of manufacturing functional molecular device, and method of manufacturing integrated element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing functional molecular elements that can discriminatingly manufacture a first functional molecular element having a bias voltage region showing negative differential resistance and a second functional molecular element having diode characteristics, to provide a method of manufacturing a functional molecular device, and to provide a method of manufacturing an integrated element comprising a plurality of kinds of functional molecular elements. <P>SOLUTION: In the method, π electron conjugated molecules 1 each of which is a kind of linear tetra-pyrrole and has a nearly discoidal center frame part 2 and a flexible side chain part 3 composed of an alkyl group are dissolved in 4-pentyl-4'-cyanobiphenyl and adjusted to a suitable concentration. The solution is stuck to electrodes 5, 6 and liquid crystal solvent molecules are evaporated from the solution to form an array structure 4 of the π electron conjugated molecules 1 in a self-organizing manner. In this case, the first functional molecular element or a second functional molecular element is discriminatingly manufactured by setting the evaporation temperature to temperature at which liquid crystal solvent molecules form a liquid crystal phase or to temperature at which liquid crystal solvent molecules form a liquid phase. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a functional molecular element having specific conductivity, a method for producing a functional molecular device having the element, and a method for producing an integrated element in which a plurality of types of functional molecular elements are integrated. is there.

Nanotechnology is a technique for observing, producing, and utilizing a microstructure having a size of about 10 ⁻⁸ m (= 10 nm). In the late 1980s, a scanning tunneling microscope was invented, allowing not only to observe atoms and molecules but also to operate them one by one. For example, an example in which letters are written by arranging atoms on the surface of a crystal has been reported.

  However, even if atoms and molecules can be manipulated, it is not practical to assemble a new material or device by manipulating an enormous number of atoms or molecules one by one. Manipulating atoms, molecules and their groups to form the desired structure requires new processing techniques that enable it. As such a molecular level processing technology, attention is focused on a bottom-up method in which atoms, molecules, and groups thereof are viewed as parts, and these parts are assembled into a structure by a method such as self-organization.

  Research has also been conducted on metal, ceramics, and semiconductors to create nanometer-sized structures in a bottom-up manner. However, each molecule is independent, and there are millions of different types such as different shapes and functions, so if you take advantage of them, molecular devices with completely different characteristics from the conventional ones. It is expected that can be produced.

  For example, the width of the conductive molecule is only 0.5 nm. This molecular wire can realize high-density wiring several thousand times larger than the line width of about 100 nm realized by the current integrated circuit technology. For example, when one molecule is used as a storage element, a recording density of 10,000 times or more that of DVD can be achieved.

  In 1986, Mitsubishi Electric's Hiroshi Hizuka developed the world's first organic transistor made of polythiophene (polymer). Since then, molecular devices with various functions such as organic thin film transistors, molecular switches, molecular logic circuits, and molecular wires have been actively studied.

  One problem with molecular devices is that the connecting portion between the constituent molecules and the electrodes has a large electrical resistance, which limits the properties of the molecular device. For example, in an organic field effect transistor, carrier movement in the organic molecule is modulated by a change in the electric field acting on the organic molecule in the channel region. At this time, the contact resistance at the interface between the constituent molecule and the electrode is very large. The contact resistance strongly affects the operation characteristics of the transistor.

  For example, one of the inventors of the present invention proposed a functional molecular element based on a new principle that functions as a molecular switch that changes the molecular structure by the action of an electric field and turns the current on and off in Japanese Patent Application Laid-Open No. 2004-221553. However, even in this molecular element, when the contact resistance at the interface between the constituent molecule and the electrode is large, the contact resistance affects the operating characteristics of the molecular element.

  Further, even when a molecular layer for allowing electrons to flow is disposed between the counter electrodes as in an organic solar cell, it is required to reduce the contact resistance at the interface between the organic molecule and the electrode as much as possible.

  Therefore, one of the inventors of the present invention disclosed a functional molecular element having a novel structure capable of reducing the contact resistance at the interface between a constituent molecule and an electrode, a manufacturing method thereof, and a functional molecular device in Patent Document 1 described later. Proposed.

This functional molecular element is, for example,
A π-electron conjugated molecule in which a side chain portion is bonded to a skeleton portion having a planar or substantially planar structure composed of a π-electron conjugated system is adsorbed to the electrode in the side chain portion, whereby the skeleton portion The adsorbed molecules are arranged such that the planar or substantially planar structure is substantially parallel to the electrode,
A structure comprising at least the molecules to be adsorbed and the electrode has a function of flowing a current in a direction intersecting the planar shape or the substantially planar structure;
It is a functional molecular device.

Japanese Patent Laying-Open No. 2006-351623 (page 11-15, FIG. 1-5)

  Research on the functional molecular device proposed in Patent Document 1 has just started, and it is considered that if the research proceeds, functional molecular devices having various novel characteristics can be provided. In fact, the present inventor reverses the case in which the first functional molecular element having a bias voltage region exhibiting negative differential resistance at room temperature and the bias voltage are applied in the positive direction in Japanese Patent Application No. 2006-308881. A second functional molecular device having a diode characteristic that differs greatly in conductivity when applied in the direction was reported.

  These two types of functional molecular elements are, for example, one type of linear tetrapyrrole, which is made of the same π-electron conjugated molecule having a substantially disc-shaped central skeleton portion and a flexible side chain portion made of an alkyl group. It is made as follows. In the first functional molecular element, this π-electron conjugated molecule was dissolved in 4-pentyl-4′-cyanobiphenyl (5CB) or the like, adjusted to an appropriate concentration, and this solution was deposited on the counter electrode. Thereafter, by evaporating the solvent, the array structure of the π-electron conjugated molecules is formed in a self-organized manner between the counter electrodes. The second functional molecular element can be produced in the same manner except that the solvent for dissolving the π-electron conjugated molecule is changed from 5CB to tetrahydrofuran.

  The manufacturing method of said 1st functional molecular element and said 2nd functional molecular element is the outstanding functional molecule which can make the 1st and 2nd functional molecular element separately only by changing a solvent. It is a manufacturing method of an element. However, in order to form the first functional molecular element and the second functional molecular element at predetermined positions on the same substrate and assemble them into an integrated circuit, the first function molecular element is used by using two kinds of solvents, respectively. A step of patterning and forming the functional molecular element and a step of patterning and forming the second functional molecular element are required. In this case, after forming the first element, when the second element is formed, each element is patterned and formed, such as how to protect the first element. There are various difficulties. Correspondingly, the manufacturing process requires a large number of processes and is expected to be complicated.

  The object of the present invention has been made in view of the above circumstances, and the production of a functional molecular element capable of easily making a first functional molecular element and a second functional molecular element. It is an object of the present invention to provide a method, a method for manufacturing a functional molecular device, and a method for manufacturing an integrated device including a plurality of types of functional molecular devices.

That is, in the present invention, a counter electrode in which a plurality of electrodes are arranged to face each other is formed, and a π-electron conjugate formed by combining a side chain portion with a skeleton having a substantially planar structure composed of a π-electron conjugated system. The molecule to be adsorbed is arranged so that the substantially planar structure of the skeleton is substantially parallel to the counter electrode by adsorbing the system molecule to the electrode in the side chain portion. Formed for any of the electrodes,
A structure including at least the molecule to be adsorbed and the counter electrode has a function of flowing a current in a direction crossing the substantially planar structure in accordance with a bias voltage applied between the counter electrodes;
A method for producing a functional molecular element, which produces a first functional molecular element having a bias voltage region exhibiting negative differential resistance at room temperature,
Preparing a solution in which the π-electron conjugated molecule is dissolved in a solvent composed of liquid crystalline solvent molecules by adjusting the concentration;
Contacting the solution with the electrode;
In the temperature range where the liquid crystalline solvent molecules form a liquid crystal phase, the liquid crystalline solvent molecules are evaporated from the solution, and the π-electron conjugated molecule layer is formed on the surface of the electrode with the number of molecular stacks according to the concentration. And a process for forming the first functional molecular device.

Further, a counter electrode in which a plurality of electrodes are arranged to face each other is formed, and a π-electron conjugated molecule in which a side chain portion is bonded to a skeleton portion having a substantially planar structure made of a π-electron conjugated system, Adsorbed molecules arranged so that the substantially planar structure of the skeletal portion is substantially parallel to the counter electrode by being adsorbed to the electrode in the side chain portion may be any of the counter electrodes. Also formed for
A structure including at least the molecule to be adsorbed and the counter electrode has a function of flowing a current in a direction crossing the substantially planar structure in accordance with a bias voltage applied between the counter electrodes;
A method for producing a functional molecular device, wherein a second functional molecular device having a remarkably different conductivity between when the bias voltage is applied in the forward direction and when applied in the reverse direction,
Preparing a solution in which the π-electron conjugated molecule is dissolved in a solvent composed of liquid crystalline solvent molecules by adjusting the concentration;
Contacting the solution with the electrode;
In a temperature range where the liquid crystalline solvent molecules form a liquid phase, the liquid crystalline solvent molecules are evaporated from the solution, and the π-electron conjugated molecule layer is formed on the surface of the electrode with the number of molecular stacks according to the concentration. And a step of forming the second functional molecular device.

  The present invention also includes a step of producing a first functional molecular element by the above-described method for producing a first functional molecular element, and applying an electric field to the first functional molecular element, so that at least the target molecular element is produced. And a step of providing a control electrode for controlling the current flowing through the structure including an adsorbed molecule and the counter electrode along a stacking direction of the structure. Is.

Moreover, the 1st functional molecular element produced with the manufacturing method of the said 1st functional molecular element and the 2nd functional molecular element produced with the said manufacturing method of the said 2nd functional molecular element are the following. , A method of manufacturing an integrated device integrated on a substrate,
Forming the electrode at a predetermined position of the substrate;
Preparing a solution in which the π-electron conjugated molecule is dissolved in a solvent composed of liquid crystalline solvent molecules by adjusting the concentration;
Contacting the solution with the electrode;
In the region where the first functional molecular element is formed, the temperature of the arranged solution is maintained at a temperature at which the liquid crystalline solvent molecules form a liquid crystal phase, and the second functional molecular element is In the region to be formed, the liquid crystal solvent molecules are evaporated from the solution while maintaining the temperature of the arranged solution at a temperature at which the liquid crystal solvent molecules form a liquid phase, and the molecular stacking according to the concentration is performed. And forming a layer of the π-electron conjugated molecule on the surface of the electrode.

In the first and second functional molecular element manufacturing methods of the present invention, a counter electrode in which a plurality of electrodes are arranged to face each other is formed, and a skeleton having a substantially planar structure made of a π-electron conjugated system The π-electron conjugated molecule formed by bonding the side chain to the electrode is adsorbed to the electrode in the side chain, so that the substantially planar structure of the skeleton is substantially parallel to the counter electrode. The adsorbed molecules arranged in such a manner are formed on any of the counter electrodes,
A functional molecule having a function of causing a current to flow in a direction intersecting the substantially planar structure in accordance with a bias voltage applied between the counter electrodes, at least in a structure including the adsorbed molecule and the counter electrode A method of manufacturing an element, wherein the first functional molecular element having a bias voltage region exhibiting negative differential resistance at room temperature, and the case where the bias voltage is applied in the forward direction and the reverse direction, respectively. This is a manufacturing method for manufacturing the second functional molecular element in which the conductivity is remarkably different when applied.

  According to these functional molecular device manufacturing methods, a step of preparing a solution in which the π-electron conjugated molecule is dissolved in a solvent composed of liquid crystalline solvent molecules by adjusting the concentration, and contacting the solution with the electrode And evaporating the liquid crystalline solvent molecules from the solution in a temperature range where the liquid crystalline solvent molecules form a liquid phase, and forming the layer of the π-electron conjugated molecules with the number of molecular stacks according to the concentration. And the step of forming on the surface of the electrode, it is possible to reliably obtain the functional molecular element in which a predetermined number of π-electron conjugated molecular layers are stacked on the adsorbed molecules.

  In addition, as a result of intensive studies by the inventor, these two types of functional molecules use the same π-electron conjugated molecule as a constituent material, while using a solvent composed of the same liquid crystalline solvent molecule, The temperature at the time of evaporating the liquid crystalline solvent molecules is easily determined depending on whether the liquid crystalline solvent molecules form a liquid crystal phase or the liquid crystalline solvent molecules form a liquid phase. It turned out that it can be made separately. As described later, this is considered to be related to the difference in the existence state of the π-electron conjugated molecules in the liquid crystal phase and the liquid phase.

  Moreover, since the manufacturing method of the functional molecular device of this invention produces a 1st functional molecular element with the manufacturing method of an above described 1st functional molecular element, the manufacturing method of the said 1st functional molecular element Similarly to the above, it is possible to reliably manufacture a functional molecular device including the first functional molecular element.

In the integrated device manufacturing method of the present invention, the concentration of the step of forming the electrode at a predetermined position of the substrate and the solution in which the π-electron conjugated molecule is dissolved in a solvent composed of liquid crystalline solvent molecules are adjusted. And the step of bringing the solution into contact with the electrode,
In the region where the first functional molecular element is formed, the temperature of the arranged solution is maintained at a temperature at which the liquid crystalline solvent molecules form a liquid crystal phase, and the second functional molecular element is In the region to be formed, the liquid crystalline solvent molecules are evaporated from the solution while keeping the temperature of the arranged solution at a temperature at which the liquid crystalline solvent molecules form a liquid phase. By simply controlling the temperature, the first functional molecular element and the second functional molecular element can be made separately at the same time.

  In the first functional molecular device manufacturing method and the second functional molecular device manufacturing method of the present invention, as a part of the structure, a π-electron conjugated molecule of the same kind as the adsorbed molecule or / and An array structure in which different types of π-electron conjugated molecules are stacked in one direction by intermolecular π-π stacking in the skeleton with respect to the skeleton of the adsorbed molecule is formed between the counter electrodes. It is preferable that a current flows in the stacking direction of the array structure. As described above, when the array structure is formed by the intermolecular π-π stacking, current can be effectively passed in the stacking direction of the array structure by the interaction between π electrons.

  As the liquid crystalline solvent molecule, an organic molecule having a rod-like molecular skeleton and having a large polar functional group at one end thereof may be used. At this time, as the solvent molecule, an organic molecule in which the functional group having a large polarity is a cyano group is preferably used, and at least one selected from cyanobiphenyls is preferably used. For example, 4-pentyl-4'-cyanobiphenyl may be used as the cyanobiphenyls.

  As the π-electron conjugated molecule, a π-electron conjugated molecule in which the side chain portion has a flexible structure is preferably used. If it is like this, the said side chain part will become easy to be adsorb | sucked on the said electrode, and resistance between the said electrodes can be reduced. The side chain portion may be composed of an alkyl group, an alkoxy group, a silanyl group, or an aromatic ring to which an alkyl group, an alkoxy group, or a silanyl group is bonded.

  As the π-electron conjugated molecule, a complex of a central metal ion and a linear tetrapyrrole derivative is preferably used. In particular, the array structure formed of a complex having zinc ions as a central metal ion exhibits excellent ON / OFF switching characteristics depending on the presence or absence of an applied electric field, so that a transistor or the like can be manufactured. As the central metal ions, transition elements such as copper ions and nickel ions and metal ions of typical elements can be used in addition to zinc ions.

Further, at least the π-electron conjugated molecule is preferably a biradienone derivative represented by the following general formula (1).
General formula (1):
(In this general formula (1), R ¹ , R ² , R ³ , and R ⁴ are the same or different alkyl groups having 3 to 12 carbon atoms, which are independent of each other.)

At this time, R ¹ , R ² , R ³ , and R ⁴ may have 3 to 12 carbon atoms, and examples thereof include —C ₁₀ H ₂₁ and —C ₁₂ H ₂₅ . With such a side chain having the number of carbon atoms, the π-electron conjugated molecule is fixed in a well-oriented state on the electrode without crystallization, and the synthesis is easy. On the other hand, when the number of carbon atoms is 1 or 2, the π-electron conjugated molecule is easily crystallized, and does not exhibit liquid crystal properties and easily causes orientation failure. On the other hand, when the number of carbon atoms is 13 or more, the orientation becomes difficult and the synthesis becomes difficult.

  In the method for producing a functional molecular device of the present invention, a gate insulating layer is provided on the control electrode, and a source electrode and a drain electrode are formed on the insulating layer as the counter electrode, and at least the source electrode and the drain are formed. It is preferable to manufacture the insulated gate field effect transistor as a functional molecular device by arranging the structure body between the electrodes.

  In the integrated element manufacturing method of the present invention, it is preferable that the functional molecular device is constituted by the first functional molecular element.

  Next, a preferred embodiment of the present invention will be specifically described with reference to the drawings.

Embodiment 1
In the first embodiment, an example of a method for manufacturing a first functional molecular element corresponding to claim 1 and an example of a method for manufacturing a second functional molecular element corresponding to claim 13 will be mainly described.

<Selection of π-electron conjugated molecules>
FIG. 8A is a structural formula showing an example of the molecular structure of the π-electron conjugated molecule 1 constituting the array structure 4 in Embodiment 1 of the present invention. FIG. 8B is a schematic diagram for mainly showing the three-dimensional structure of the substantially disc-like skeleton part 2 of the π-electron conjugated molecule 1 shown in FIG. In FIG. 8B, the metal ions M, nitrogen atoms, carbon atoms, and oxygen atoms forming the skeleton 2 are shown as spheres, the hydrogen atoms are not shown, and the side chain 3 is very simple. Are omitted.

  As shown in FIGS. 8A and 8B, the skeleton 2 of the π-electron conjugated molecule 1 has a basic structure of biradienone (specifically, 4,9-biradien-1-one). Biradienone is a kind of linear tetrapyrrole having a structure corresponding to a ring-opened porphyrin ring. The skeleton 2 has a porphyrin-like rigid, substantially planar structure formed by a π-electron conjugated system, but two carbonyl groups (C═O groups) are formed at the cleaved portion of the opened porphyrin ring. Since they are facing each other, they are twisted slightly from the plane shape, and have a substantially disk shape that spirals to leave flexibility. M at the center of the substantially disk-like structure is a metal ion such as zinc ion, which is useful for the functional molecular device to exhibit switching characteristics.

  The π-electron conjugated molecule 1 is formed by bonding a side chain portion 3 made of a p-alkylphenyl group to the skeleton portion 2. The side chain portion 3 forms a flexible chain structure by intramolecular rotation around the CC axis.

<Structure of functional molecular element>
FIG. 9A is a schematic diagram schematically showing the structure of the functional molecular element 10 based on the first embodiment, and FIG. 1B is a schematic diagram of the array structure 4 constituting the molecular element 10. It is explanatory drawing which shows the orientation structure with respect to the electrode of 1 layer (pi) electron conjugated system molecule | numerator 1 (the said to-be-adsorbed molecule | numerator 9 adsorb | sucked to the electrode surface).

  FIG. 9A shows an example in which a π-electron conjugated molecule 1 having a substantially disc-shaped skeleton 2 has a disk surface between two electrodes 5 and 6 having a nanoscale gap, for example, made of gold. A functional molecular element 10 in which a columnar array structure 4 is formed by aligning in parallel with the surfaces of 5 and 6 and arranging in one direction is shown.

  Conventionally, when an array structure is formed using a rigid disc or a π-electron conjugated molecule having a substantially disc-like skeleton, such as the π-electron conjugated molecule 1, a disc or a substantially disc-like skeleton of each molecule is formed. It is known that parts are stacked parallel to each other by π-π electron interaction (so as to face-to-face), and π electrons are delocalized between the stacked skeleton parts. In particular, in the case of a molecule having a long-chain (6 or more carbon atoms) alkyl group side chain (such as a discotic liquid crystal), the π-electron conjugated molecules are stacked in a column shape and exhibit high conductivity in the stacking direction. (See Y. Shimizu, T. Higashiyama and T. Fuchita, “Photoconduction of a mesogenic long-chain tetraphenylporphyrin in a symmetrical sandwich-type cell”, Thin Solid Films, 331 (1998), 279-284).

  It is also said that metal ions may be coordinated near the center of a disc or a substantially disc-shaped skeleton (Y. Shimizu, “Phtoconductivity of Discotic Liquid Crystals: a Mesogenic Long-Chain Tetraphenylporphyrin and Its Metal Complexes. ", Molecular Crystals and Liquid Crystals, 370 (2001), 83-91, STTrzaska, HF. Hsu and TMSwager," Cooperative Chirality in Columnar Liquid Crystals: Studies of Fluxional Octahedral Metallomesogens ", J. Am. Chem. Soc. , 121 (1999), 4518-4519, and Hiroshi Shimizu, “Columnar Liquid Crystals and Their Various Molecular Structures and Intermolecular Interactions”, Liquid Crystals, 6 (2002), 147-159).

  As an example of the function of the array structure formed by π-π stacking of substantially disc-shaped π-electron conjugated molecules such as linear tetrapyrrole as described above, a pipe that allows the flow of electrons in the stacking direction (channel chain) ) Can be considered. Compared to ordinary conductive chain molecules, the diameter of the current path is large and a large amount of current can flow, and research is actively conducted to use it as an electronic channel of a solar cell.

  However, in the case where the above array structure is used as a conductor, as shown in FIG. 9A, the stacking direction of the array structure 4 in the direction in which a current is to flow (direction in which the electrode 5 and the electrode 6 are connected). And the ends of the array structure 4 need to be arranged so as to be in close contact with the surfaces of the electrodes 5 and 6 so that the contact resistance of the electrodes 5 and 6 is reduced.

  When molecules without side chains are used as the π-electron conjugated molecules that make up the array structure, a group that controls the adsorption state on the electrode surface and selectively orients the disk surface parallel to the electrode surface. Therefore, the orientation of the π-electron conjugated system molecule relative to the electrode surface and the stacking direction of the molecules cannot be controlled.

  Therefore, in this embodiment, the π-electron conjugated molecule 1 having the flexible side chain portion 3 shown in FIG. 8A is used as the π-electron conjugated molecule. Then, a solution of the π-electron conjugated molecule 1 in which the concentration of the π-electron conjugated molecule 1 is appropriately adjusted is prepared, and this solution is applied to the electrode 5 or 6 by a coating method such as a cast method, and the solvent is removed from the solution. Is evaporated, if necessary, an annealing treatment is performed, and the adsorbed molecule 9 as the adsorbed molecule is placed in close contact with the surface of the electrode 5 or 6, and π-π stacking is performed on the adsorbed molecule 9. π-electron conjugated molecules are stacked to form an array structure 4. The π-electron conjugated molecule to be laminated here is not particularly limited except that it can form π-π stacking with respect to the π-electron conjugated molecule 1. Although FIG. 9A shows an example in which the same kind of molecules as the π-electron conjugated molecule 1 is laminated, the other kind of π-electron conjugated molecule may be laminated.

  At this time, as shown in FIG. 9B, in the π-electron conjugated molecule 1 (adsorbed molecule 9) forming the first layer of the array structure 4, the flexible side chain portion 3 has the electrode 5 (or 6). ), And as a result, it is important that the substantially disk surface of the skeleton 2 is fixed so as to be in close contact with the surface of the electrode 5 (or 6). For this reason, the π electrons of the skeleton part 2 can be delocalized on the electrode, and the contact resistance at the interface between the array structure 4 and the electrode 5 (or 6) can be kept small.

  In addition, the stacking direction of the molecular layers after the second layer of the array structure 4 is set so that the skeleton portion of the lower molecular layer is based on the substantially disk surface of the skeleton portion 2 of the adsorbed molecule 9 arranged parallel to the electrode surface. It is controlled by the π-π interaction so that the substantially disk surface of the skeleton of the upper molecular layer overlaps the substantially disk surface of the upper molecular layer in parallel. The array structure 4 can effectively pass a current in the stacking direction by the interaction between π electrons.

  As described above, it is possible to obtain a robust functional molecular element 10 in which the contact resistance at the interface with the electrode is very small and the stacking direction of the array structure 4 (the direction in which current flows) is controlled.

<Characteristics of π-electron conjugated molecule used in this embodiment>
Conventionally, many attempts have been made to fabricate molecular switches using disk-shaped molecules having long alkyl chains. At this time, porphyrin, phthalocyanine (S. Cherian, C. Donley, D. Mathine, L. LaRussa, W. Xia, N. Armstrong, J. Appl. Phys., 96, 5638 (2004) AM van de Craats, N. Stutzmann, O. Bunk, MM Nielsen, M. Watson, K. Mullen, HD Chanzy, H. Sirringhaus, RH Friend, Adv. Mater., (Weinheim, Ger.), 15 , 495 (2003)) and hexabenzocoronene (J. Wu, MD Watson, K. Muellen, Angew. Chem., Int. Ed., 42, 5329 (2003)), and these compounds have The property of forming a set by self-organization is attracting attention.

While the above compound has a symmetric and completely rigid central skeleton structure, as explained with reference to FIG. 8, the central skeleton structure of the π-electron conjugated molecule 7 is asymmetric and sp ³ hybridized at the meso position. The π-electron system is discontinuous at orbital carbon and has a flexible helical conformation (reference: G. Struckmeier, U. Thewalt, JH Fuhrhop, J. Am. Chem). Soc., 98, 278 (1976), JAS Cavaleiro, MJE Hewlins, AH Jackson, MGPMS Neves, Tetrahedron Lett., 33, 6871 (1992), T. Mizutani, S. Yagi, A. Honmaru, H. Ogoshi, J. Am. Chem. Soc., 118, 5318 (1996), L. Latos-Grazynski, J. Johnson, S. Attar, MM Olmstead, AL Balch, Inorg. Chem., 37, 4493, (1998), JA Johnson, MM Olmstead, AL Balch, Inorg. Chem., 38, 5379 (1999), T. Mizutani, S. Yagi, J. Porphyrins and Phthalocyanines, 8, 226 (2004)).

  Since linear tetrapyrrole having a similar structure has been found in photoreceptor proteins, biradienone is expected to be applicable to switching elements by utilizing its flexible conformation (see above). See references).

<Production of functional molecular device>
FIG. 1 is a flowchart showing a first functional molecular device manufacturing method and a second functional molecular device manufacturing method based on the first embodiment.

In this production method, first, a solution in which π-electron conjugated molecules are dissolved in a solvent composed of liquid crystalline solvent molecules is prepared by adjusting the concentration. As the π-electron conjugated molecule, a biradienone molecule shown in FIG. This molecule is a zinc complex of a biradienone derivative having a phenyl group having a dodecyl group —C ₁₂ H ₂₅ bonded to the para position as the flexible side chain portion 3 (hereinafter, abbreviated as biradienone). As the liquid crystalline solvent molecule, 4-pentyl-4′-cyanobiphenyl (5CB) shown in FIG.

  Next, this solution is placed in contact with the counter electrode.

  Next, the liquid crystalline solvent molecules are evaporated from the solution, and a layer of π-electron conjugated molecules is formed on the surface of the electrode with the number of molecular stacks corresponding to the concentration of the solution. By forming in this way, a functional molecular element in which a predetermined number of stacked π-electron conjugated molecular layers are stacked on adsorbed molecules can be reliably obtained.

  At this time, the temperature at which the liquid crystalline solvent molecules are evaporated from the solution is set to a temperature at which the liquid crystalline solvent molecules form a liquid crystal phase based on the method for producing the first functional molecular element, or the second Based on the manufacturing method of the functional molecular element, the first functional molecular element and the second functional molecular element can be easily made separately depending on whether the temperature is set to form a liquid phase. This is because the difference in the existence state of the π-electron conjugated molecules in the liquid crystal phase and the liquid phase, that is, in the liquid crystal state 5CB, biradienone exists as a dimer, and in the liquid state 5CB, biradienone is a simple substance. It is thought that it exists as a mer. Hereinafter, this point will be described.

<Examination of liquid crystallinity of a solution in which biradienone is dissolved in 5CB>
5CB is a liquid crystal molecule capable of forming a nematic phase (liquid crystal-liquid phase transition temperature is about 35 ° C.). In order to examine the liquid crystal properties of 5CB added with biradienone, a 5CB solution of biradienone was observed with a polarizing microscope at 25 ° C. and 50 ° C. The concentration of this solution is 3.9 × 10 ⁻³ M.

  FIG. 3 is a photograph showing the result. FIG. 3A is an observation image at 25 ° C., and a schlieren texture was observed, so that it can be confirmed to be a nematic phase derived from 5CB. FIG.3 (b) is an observation image in 50 degreeC, and since a schlieren texture is not seen, it can confirm that it is an isotropic liquid. From these facts, it is understood that even when biradienone is added to 5CB, a liquid crystal-liquid phase transition occurs due to a temperature change from 25 ° C. to 50 ° C.

<Existence state of viradienone in 5CB solution>
In 5CB in the liquid crystal state, biradienone exists mainly as a dimer, and in 5CB in the liquid state, biradienone exists mainly as a monomer. This is demonstrated by the following experiment (Kita, K .; Tokuoka, T .; Monno, E .; Yagi, S .; Nakazumi, H .; Mizutani, T. Tetrahedron Lett. (2006), 47, (See 1533.)

As for biradienone in a solution, a dimer and a monomer exist in an equilibrium state as shown in the following reaction formula.
Reaction (1):
(Viradienone) ₂ ⇔ 2 Viradienone K ₁ = [Biradienone] ² / [(Biradienone) ₂ ]
In the formula, (biladienone) ₂ represents a dimer of biradienone, K ₁ represents the equilibrium constant of reaction (1), and [] represents the molar concentration of the component in parentheses.

When the equilibrium of reaction (1) is overwhelmingly biased toward the dimer, the concentration of each component is approximately given by the following equation from the above equilibrium relationship.
[(Biradienone) ₂ ] = C / 2
[Viradienone] = (K ₁ C / 2) ^1/2
However, in the formula, C is the molar concentration of the viradienone solution.

Conversely, when the equilibrium of reaction (1) is overwhelmingly biased toward the monomer, the monomer concentration is approximately given by the following equation, ignoring the dimer concentration.
[Viradienone] = C

On the other hand, the monomer produces an anhydride by dehydration reaction (2), but there is no reaction in which an anhydride is produced from the dimer.
Reaction (2):
Viradienone → Anhydride + H ₂ O
Therefore, if the rate of anhydride formation is V, V is given by
V = k ₂ [biradienone]
In the formula, k ₂ is the reaction rate constant of the reaction (2).

From the above, when the equilibrium of reaction (1) is overwhelmingly biased toward the dimer, V is approximately given by the following equation.
V = k ₂ (KC / 2) ^1/2 = k ₂ (K / 2) ^1/2 C ^1/2
On the other hand, when the equilibrium of reaction (1) is overwhelmingly biased toward the monomer, V is approximately given by the following equation.
V = k ₂ C

  As described above, when the equilibrium of reaction (1) is overwhelmingly biased toward the dimer side and overwhelmingly biased toward the monomer side, the concentration of the biradienone solution having an anhydride generation rate V The dependency on C is different. Therefore, by examining the relationship between V and C, information on the association of viradienone in the solution can be obtained.

  FIG. 4 is a graph illustrating the logarithm of the initial rate of the anhydride formation rate V with respect to the logarithm of the initial value of the concentration C of the biradienone solution, and the slope of the graph represents the dependence of V on C. . FIG. 4A shows the result in 5CB in the liquid crystal state, and FIG. 4B shows the result in 5CB in the liquid state. Since the slope of the graph of FIG. 4 (a) is ½ of the slope of the graph of FIG. 4 (b), in the 5CB liquid crystal state, an overwhelmingly large amount of viradienone exists as a dimer, In 5CB in the liquid state, it can be seen that an overwhelmingly large amount of biradienone exists as a monomer. In THF, biradienone exists as a monomer. In addition, toluene is known as a solvent in which biradienone is present as a dimer.

<Mechanism for controlling the association state of viradienone by 5CB liquid crystal-liquid phase transition>
As described above, by controlling the temperature of the 5CB solution of biradienone, the liquid crystal-liquid phase transition of the 5CB solution can be controlled, and thereby the association state of biradienone in the solution can be controlled.

  5CB in the liquid crystal state is a nematic phase, and is composed of a large number of anisotropic domains when alignment treatment is not performed as in this study. Therefore, 5CB molecules in a liquid crystal state have a weaker function of solvating to biradienone by hydrogen bonds, coordination bonds, or the like than 5CB in an isotropic liquid state. As a result, it is considered that the function of dissociating associations between biradienones is weak and dimers are likely to be formed in 5CB in a liquid crystal state.

  The possibility that the dissociation from the dimer to the monomer is simply due to a temperature change cannot be denied immediately. For example, the dimer formed in toluene is maintained even at 50 ° C. or higher. Such a possibility is unlikely.

<Example of fabrication of functional molecular device>
FIG. 5A is a cross-sectional view of the functional molecular element 10 formed on the substrate. The first functional molecular element or the second functional molecular element 10 made of biradienone is prepared as follows from a 2 mM concentration solution using 5CB as a solvent.

  First, biradienone is synthesized by reacting biradienone without a corresponding central metal ion with zinc acetate. Viradienone without a central metal ion has been described in the literature (T. Yamauchi, T. Mizutani, K. Wada, S. Horii, H. Furukawa, S. Masaoka, H.-C. Chang, S. Kitagawa, Chem. Commun., 1309 (2005)).

Next, as shown in FIG. 5A, a doped silicon substrate 11 is prepared, and an insulating layer 12 made of a silicon oxide SiO ₂ layer having a thickness of 70 nm is formed on the surface thereof. The silicon substrate 11 also serves as a gate electrode, and the silicon oxide insulating layer functions as the gate insulating film 12.

  Next, a chromium Cr layer having a thickness of 5 nm and a gold Au layer having a thickness of 20 nm are stacked, and the counter electrodes 5 and 6 having a gap of 16 nm are formed by electron beam lithography. FIG. 5B is an electron micrograph of the electrodes 5 and 6. FIG. 5A is a cross-sectional view taken along the line 5A-5A in FIG.

  Next, 1 μL of the solution is dropped at the position of the gap between the counter electrodes. If the first functional molecular device is stored for 7 days, and then the first functional molecular device is manufactured, the 5CB solution is maintained at a temperature at which the liquid crystal state is obtained. While maintaining the temperature at which the 5CB solution takes a liquid state, the 5CB molecules are evaporated under vacuum to remove the 5CB molecules from the functional molecular device.

<Electrical measurement>
These first functional molecular elements 10 or second functional molecular elements 10 are biased from −2 V to +2 V as pre-processing for causing the biradienone molecules to take a predetermined orientation before electrical measurement. The voltage is applied over 2 hours. At this time, it is important to increase the applied bias voltage by 50 mV in order to lead the biradienone molecules to a predetermined alignment state. Therefore, a bias voltage of −2V is first applied, the bias voltage is increased by 50 mV per step, and a bias voltage of + 2V is obtained after 80 steps.

  A semiconductor parameter analyzer (Agilent 4156B) equipped with a nanoprobe system (Nagase Electronic Equipments Service Co., Ltd. BCT-11MDC-4K) is used for electrical measurement of the functional molecular element 10 shown in FIG. Etc. are used. Since this apparatus can set the bias voltage Vs in a programmable manner, the current-voltage curve of the functional molecular element 10 can be measured while applying a preset bias voltage to the functional molecular element 10. The nanoprobe system has a sample chamber that is shielded from the outside air by a hermetic seal, and this sample chamber is cleaned with a jet of nitrogen gas to minimize contamination by oxygen and moisture. Yes.

  FIG. 6 is a current-voltage curve of the functional molecular element 10 prepared from a 5CB solution in a liquid crystal state. When the gate voltage Vg is not applied, two regions exhibiting negative differential resistance (NDR) exist symmetrically on the negative bias voltage side and the positive bias voltage side. When a negative gate voltage is applied, two additional NDR peaks appear on the positive bias voltage side in the region where the bias voltage is smaller than the NDR region. When a positive gate voltage is applied, there is no region showing negative differential resistance (NDR) (data not shown).

  FIG. 7 is a current-voltage curve of the functional molecular element 10 produced from the liquid 5CB solution when no gate voltage is applied. These curves have almost no straight line portion, and the negative bias voltage side and the positive bias voltage side are asymmetric. When the bias voltage is applied in the forward direction and when it is applied in the reverse direction, the conductivity is remarkably different and it has diode characteristics. In a region where a positive bias voltage is applied, the current rapidly increases when a large voltage is applied, and the current-voltage curve does not show reproducibility when a larger voltage is applied. In the region where the negative bias voltage is applied, there is hysteresis with different current-voltage curves depending on whether the bias voltage increases or decreases. The current-voltage curve of this functional molecular device does not show an important change even if a gate voltage is applied, with only a slight change in the slope of the curve.

<Control of association state of biradienone and creation of functional molecular device>
In the 5CB solution in the liquid state, biradienone exists mainly as a monomer. When the functional molecular element 10 is formed from this liquid state, the biradione molecules are stacked so that a large number of dishes having the same shape are stacked in the same direction by π-π stacking, and the biradienone molecules are regularly arranged in one direction. It is expected to form fewer array structures. This array structure has high conductivity because current flows effectively in the stacking direction due to interaction between π electrons, and has anisotropy in the positive and reverse directions of the stacking direction. It is expected that the conductivity is different between when applied in the forward direction and when applied in the reverse direction. In addition, since there is little room for deformation, it is expected that the gate voltage is hardly affected. These characteristics agree well with those of the second functional molecular element.

  On the other hand, in the 5CB solution in the liquid crystal state, viradienone exists mainly as a dimer. When the functional molecular element 10 is formed from this dimer, the structure of the array structure is expected to be a structure with increased irregularities and gaps and a large room for deformation compared to the case of forming from a monomer. The For this reason, in this array structure, it is expected that the interaction between π electrons is weakened and the conductivity is lowered. Further, since the anisotropy is reduced, it is expected that the conductivity does not depend much on the direction of the bias voltage, and that there is a large room for deformation, so that it is easily affected by the gate voltage. These characteristics are in good agreement with the characteristics of the first functional molecular element.

  In this embodiment, the liquid crystal-liquid phase transition of the 5CB solution is controlled by controlling the temperature of the 5CB solution of biradienone, thereby controlling the association state of biradienone in the solution. As a result, it is controlled whether the functional molecular element 10 formed by the self-organizing action of biradienone molecules is the first functional molecular element or the second functional molecular element. That is, this embodiment is characterized in that the structure of the solution is controlled by controlling the environmental factor of temperature, and the self-organizing action of the solute biradienone molecule is controlled thereby.

Embodiment 2
In the second embodiment, as an example of a method for manufacturing a functional molecular device corresponding to claims 11 and 12, the first functional molecular device is manufactured by the first functional molecular device manufacturing method described in the first embodiment. An example in which a functional molecular device configured as an insulated gate field effect transistor is formed between the opposing electrodes 10 will be described.

  FIG. 10 is a cross-sectional view showing the structure of an insulated gate field effect transistor 20 manufactured based on the second embodiment. As shown in FIG. 10, in the insulated gate field effect transistor 20, the doped silicon substrate 11 also serves as the gate electrode 13 serving as the control electrode. A silicon oxide layer is formed as a gate insulating film 12 on the surface of the silicon substrate 11, and a source electrode 14 and a drain electrode 15 made of, for example, gold are formed as the counter electrodes on the silicon substrate 11. The array structure 4 described in the first embodiment is arranged.

  Among the π-electron conjugated molecules 1 constituting the array structure 4, the π-electron conjugated molecules that are located closest to the source electrode 14 and the drain electrode 15 and correspond to the first layer molecules are The adsorbed molecules 9 are fixed on each electrode. That is, as described with reference to FIG. 9B, in the molecule 9 to be adsorbed, the flexible side chain part 3 is adsorbed on the surface of the electrode 14 or 15, and as a result, the substantially disk surface of the skeleton part 2 is the electrode. It is fixed so as to be in close contact with the surface of 14 or 15 in parallel. For this reason, the π electrons of the skeleton 2 can be delocalized on the electrode, and the contact resistance at the interface between the array structure 4 and the electrode 14 or 15 can be kept small.

  In addition, the stacking direction of the molecular layers after the second layer of the array structure 4 is set so that the skeleton portion of the lower molecular layer is based on the substantially disk surface of the skeleton portion 2 of the adsorbed molecule 9 arranged parallel to the electrode surface. It is controlled by the π-π interaction so that the substantially disk surface of the skeleton of the upper molecular layer overlaps the substantially disk surface of the upper molecular layer in parallel.

  As described above, a robust arrangement in which the contact resistance at the interface with the electrode is very small and the stacking direction (direction in which current flows) is controlled between the counter electrode composed of the source electrode 14 and the drain electrode 15. Structure 4 is arranged.

  The gate electrode 13 as the control electrode is provided along the stacking direction, which is the conductive direction of the array structure 4, and is orthogonal to the conductive direction of the array structure 4 by the voltage applied to the gate electrode 13. An electric field acts in the direction in which the electric field travels, and the conductivity of the array structure 4 is controlled.

  The distance (gap) between the source electrode 14 and the drain electrode 15 corresponding to the gate length is about 10 nm (about 10 molecular layers).

  In the production of the functional molecular device of the present embodiment, the array structure 4 constituting the functional molecular element 10 is formed between the counter electrodes by the first functional molecular element manufacturing method described in the first embodiment. As a result, the contact resistance at the interface between the π-electron conjugated molecule 1 and the source electrode 14 and the drain electrode 15 can be kept small, and a current can be effectively passed in the stacking direction of the array structure 4. It is possible to obtain a nano-sized insulated gate field effect transistor 20 having excellent mechanical characteristics.

Embodiment 3
In the third embodiment, as an example of the method of manufacturing an integrated device corresponding to claims 24 and 25, the first functional molecular device is formed by the first functional molecular device manufacturing method described in the first embodiment. The second functional molecular element is formed on the same substrate by the method for manufacturing the second functional molecular element, and the first functional molecular element and the second functional molecular element are formed. An example of manufacturing an integrated element integrated on a substrate will be described.

  11A and 11B are a partial plan view (a) and a partial cross-sectional view (b) showing the configuration of the integrated element manufactured by the integrated element manufacturing method according to the third embodiment. FIG. 11B shows a slightly enlarged cross section at the position indicated by the line 11B-11B in FIG. As shown in FIG. 11, in the integrated element 30, a silicon oxide layer is formed as a gate insulating film 12 on the surface of a doped silicon substrate 11, and a first functional molecular element 31 and a second functionality are formed thereon. Molecular elements 32 are formed at predetermined positions.

  In order to fabricate the integrated element 30, the concentration of a step of forming the electrodes 35 and 36 at predetermined positions on the substrate 11 and a solution in which π-electron conjugated molecules are dissolved in a solvent composed of liquid crystalline solvent molecules are adjusted. After the step of preparing and the step of bringing the solution into contact with the electrode, in the region where the first functional molecular element 31 is formed, the temperature of the arranged solution is the temperature at which the liquid crystalline solvent molecules form a liquid crystal phase. In the region where the second functional molecular element 32 is formed, the temperature of the arranged solution is maintained at the temperature at which the liquid crystalline solvent molecules form a liquid phase, and the liquid crystalline solvent molecules are removed from the solution. And a layer of π-electron conjugated molecules is formed on the surface of the electrode with the number of molecular stacks corresponding to the concentration.

  The silicon substrate 11 also serves as the gate electrode 13, and the first functional molecular element 31 is configured as the insulated gate field effect transistor 20 shown in FIG.

  The temperature of the solution is maintained in the region where the first functional molecular element is formed, and the temperature of the solution is maintained in the region where the liquid crystalline solvent molecule forms the liquid crystal phase, and the region where the second functional molecular element is formed. The method for maintaining the temperature at which the liquid crystalline solvent molecules form a liquid phase is not particularly limited. For example, while maintaining the environmental temperature at a temperature at which the liquid crystalline solvent molecules form a liquid crystal phase, the region where the second functional molecular element is formed is selectively irradiated with infrared light, and the temperature of the solution in this region is set. There is a method of locally heating to a temperature at which liquid crystalline solvent molecules form a liquid phase. In order to selectively irradiate infrared light, it is preferable to use a mask that shields areas other than the irradiation area, or to scan the irradiation area with laser light using a laser as a light source. Alternatively, a light-absorbing thin film is previously formed on the surface of the substrate 11 in a region where the second functional molecular element is to be formed, and the environmental temperature is a temperature at which the liquid crystalline solvent molecules form a liquid crystal phase. The surface of the substrate 11 is irradiated with light while keeping the temperature of the solution in a region where the second functional molecular element is to be formed locally, so that the liquid crystalline solvent molecules form a liquid phase. There is.

  As mentioned above, although this invention was demonstrated based on embodiment, it cannot be overemphasized that this invention is not limited to these examples at all, and can be suitably changed in the range which does not deviate from the main point of invention.

  The functional molecular device having a novel structure capable of reducing the contact resistance at the interface between the constituent molecule and the electrode, the manufacturing method thereof, and the functional molecular device of the present invention include various switches, transistors, memories, logic circuits and the like. It can be applied to the field of electronic devices, and can be manufactured from the same material and principle from macro size to nano size element.

It is a flowchart which shows the manufacturing method of the 1st functional molecular device based on Embodiment 1 based on Embodiment 1 of this invention, and the manufacturing method of a 2nd functional molecular device. FIG. 5 is a structural formula showing the structures of π-electron conjugated molecules and liquid crystalline solvent molecules suitable for the production of functional molecular elements. It is the photograph which observed the 5CB solution of biradienone with the polarizing microscope at 25 degreeC and 50 degreeC. FIG. 6 is a graph showing the relationship between the production rate V of dehydrated body and the viradienone concentration C. FIG. It is sectional drawing (a) of a functional molecular element, and the electron micrograph (b) of an electrode similarly. It is a graph which shows the electric current-voltage characteristic of the functional molecular element produced from the 5CB solution of a liquid crystal state similarly. It is a graph which shows the electric current-voltage characteristic of the functional molecular element produced from the 5CB solution of the liquid state similarly. Similarly, a structural formula (a) showing an example of a molecular structure of a π-electron conjugated molecule constituting an array structure, and a schematic diagram for showing a three-dimensional structure of a substantially disc-like skeleton part of the π-electron conjugated molecule (b) ). FIG. 4 is an explanatory diagram (a) of the functional molecular element and an explanatory diagram (b) showing the orientation structure of the π-electron conjugated molecule (adsorbed molecule) in the first layer of the array structure. It is sectional drawing of the insulated gate field effect transistor produced by the manufacturing method of the functional molecular device based on Embodiment 2 of this invention. It is the partial top view (a) and partial sectional view (b) which show the structure of the integrated element produced by the manufacturing method of the integrated element based on Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... pi-electron conjugated system molecule, 2 ... substantially disk-shaped frame | skeleton part, 3 ... flexible side chain part,
4 ... array structure, 5, 6 ... electrode, 9 ... adsorbed molecule, 10 ... functional molecular element,
11 ... Highly doped silicon substrate (also serves as the gate electrode 13),
12 ... Gate insulating film (silicon oxide layer), 14 ... Source electrode, 15 ... Drain electrode,
16 ... gate terminal, 17 ... source terminal, 18 ... drain terminal,
20 ... Insulated gate field effect transistor, 30 ... Integrated element,
31 ... 1st functional molecular element, 32 ... 2nd functional molecular element,
34a, 34b ... array structure, 35a, 35b, 36a, 36b ... electrode

Claims (25)

A counter electrode in which a plurality of electrodes are arranged to face each other is formed, and a π-electron conjugated molecule in which a side chain is bonded to a skeleton having a substantially planar structure composed of a π-electron conjugated system is Adsorbed molecules arranged so that the substantially planar structure of the skeleton portion is substantially parallel to the counter electrode by being adsorbed to the electrode in the chain portion, with respect to any of the counter electrodes Also formed,
A structure including at least the molecule to be adsorbed and the counter electrode has a function of flowing a current in a direction crossing the substantially planar structure in accordance with a bias voltage applied between the counter electrodes;
A method for producing a functional molecular element, which produces a first functional molecular element having a bias voltage region exhibiting negative differential resistance at room temperature,
Preparing a solution in which the π-electron conjugated molecule is dissolved in a solvent composed of liquid crystalline solvent molecules by adjusting the concentration;
Contacting the solution with the electrode;
In the temperature range where the liquid crystalline solvent molecules form a liquid crystal phase, the liquid crystalline solvent molecules are evaporated from the solution, and the π-electron conjugated molecule layer is formed on the surface of the electrode with the number of molecular stacks according to the concentration. A process for producing a functional molecular device, comprising the steps of: As a part of the structure, the same kind of π-electron conjugated molecule as the adsorbed molecule or / and another kind of π-electron conjugated molecule is intermolecular π in the skeleton with respect to the skeleton of the adsorbed molecule. An array structure stacked in one direction by -π stacking is formed between the counter electrodes,
Having a function of flowing current in the stacking direction of the array structure,
The method for producing a functional molecular element according to claim 1, wherein the functional molecular element is formed.   The method for producing a functional molecular element according to claim 1, wherein an organic molecule having a rod-like molecular skeleton and having a large polar functional group at one end thereof is used as the liquid crystalline solvent molecule.   The method for producing a functional molecular element according to claim 3, wherein an organic molecule in which the functional group having a large polarity is a cyano group is used as the liquid crystalline solvent molecule.   The method for producing a functional molecular element according to claim 4, wherein at least one selected from cyanobiphenyls is used as the liquid crystalline solvent molecule.   The method for producing a functional molecular element according to claim 5, wherein 4-pentyl-4′-cyanobiphenyl is used as the cyanobiphenyls.   The method for producing a functional molecular element according to claim 1, wherein a π electron conjugated molecule having a flexible structure in the side chain portion is used as the π electron conjugated molecule.   2. The functional molecule according to claim 1, wherein the π-electron conjugated molecule comprises an alkyl group, an alkoxy group, a silanyl group, or an aromatic ring to which an alkyl group, an alkoxy group, or a silanyl group is bonded. Device manufacturing method.   The method for producing a functional molecular element according to claim 1, wherein a complex of a central metal ion and a linear tetrapyrrole derivative is used as the π-electron conjugated molecule. The method for producing a functional molecular element according to claim 9, wherein a biradienone derivative represented by the following general formula (1) is used as at least the π-electron conjugated molecule.
General formula (1):
(In this general formula (1), R ¹ , R ² , R ³ , and R ⁴ are the same or different alkyl groups having 3 to 12 carbon atoms, which are independent of each other.)   A step of producing a first functional molecular element by the production method according to claim 1; and applying an electric field to the first functional molecular element to at least the adsorbed molecule And a step of providing a control electrode for controlling the current flowing through the structure including the counter electrode along the stacking direction of the structure.   A gate insulating layer is provided on the control electrode, a source electrode and a drain electrode are formed on the insulating layer as the counter electrode, and the structure is disposed at least between the source electrode and the drain electrode, The method for producing a functional molecular device according to claim 11, wherein an insulated gate field effect transistor is produced as the functional molecular device. A counter electrode in which a plurality of electrodes are arranged to face each other is formed, and a π-electron conjugated molecule in which a side chain is bonded to a skeleton having a substantially planar structure composed of a π-electron conjugated system is Adsorbed molecules arranged so that the substantially planar structure of the skeleton portion is substantially parallel to the counter electrode by being adsorbed to the electrode in the chain portion, with respect to any of the counter electrodes Also formed,
A structure including at least the molecule to be adsorbed and the counter electrode has a function of flowing a current in a direction crossing the substantially planar structure in accordance with a bias voltage applied between the counter electrodes;
A method for producing a functional molecular device, wherein a second functional molecular device having a remarkably different conductivity between when the bias voltage is applied in the forward direction and when applied in the reverse direction,
Preparing a solution in which the π-electron conjugated molecule is dissolved in a solvent composed of liquid crystalline solvent molecules by adjusting the concentration;
Contacting the solution with the electrode;
In a temperature range where the liquid crystalline solvent molecules form a liquid phase, the liquid crystalline solvent molecules are evaporated from the solution, and the π-electron conjugated molecule layer is formed on the surface of the electrode with the number of molecular stacks according to the concentration. A process for producing a functional molecular device, comprising the steps of:   The method for producing a functional molecular element according to claim 13, wherein a functional molecular element having diode characteristics is produced. As a part of the structure, the same kind of π-electron conjugated molecule as the adsorbed molecule or / and another kind of π-electron conjugated molecule is intermolecular π in the skeleton with respect to the skeleton of the adsorbed molecule. An array structure stacked in one direction by -π stacking is formed between the counter electrodes,
Having a function of flowing current in the stacking direction of the array structure,
The method for producing a functional molecular element according to claim 13, wherein the functional molecular element is produced.   The method for producing a functional molecular element according to claim 13, wherein an organic molecule having a rod-like molecular skeleton and having a large polar functional group at one end thereof is used as the liquid crystalline solvent molecule.   The method for producing a functional molecular element according to claim 16, wherein an organic molecule in which the functional group having a large polarity is a cyano group is used as the liquid crystalline solvent molecule.   The method for producing a functional molecular element according to claim 17, wherein at least one selected from cyanobiphenyls is used as the liquid crystalline solvent molecule.   The method for producing a functional molecular element according to claim 18, wherein 4-pentyl-4′-cyanobiphenyl is used as the cyanobiphenyls.   The method for producing a functional molecular element according to claim 13, wherein a π electron conjugated molecule having a flexible structure in the side chain portion is used as the π electron conjugated molecule.   14. The functional molecule according to claim 13, wherein the π-electron conjugated molecule comprises an alkyl group, an alkoxy group, a silanyl group, or an aromatic ring to which an alkyl group, an alkoxy group, or a silanyl group is bonded. Device manufacturing method.   The method for producing a functional molecular element according to claim 13, wherein a complex of a central metal ion and a linear tetrapyrrole derivative is used as the π electron conjugated molecule. The method for producing a functional molecular device according to claim 22, wherein a biradienone derivative represented by the following general formula (1) is used as at least the π-electron conjugated molecule.
General formula (1):
(In this general formula (1), R ¹ , R ² , R ³ , and R ⁴ are the same or different alkyl groups having 3 to 12 carbon atoms, which are independent of each other.) The 1st functional molecular element produced by the manufacturing method as described in any one of Claims 1-10, and the 2nd functionality produced by the manufacturing method as described in any one of Claims 13-23. A molecular device is a method of manufacturing an integrated device integrated on a substrate,
Forming the electrode at a predetermined position of the substrate;
Preparing a solution in which the π-electron conjugated molecule is dissolved in a solvent composed of liquid crystalline solvent molecules by adjusting the concentration;
Contacting the solution with the electrode;
In the region where the first functional molecular element is formed, the temperature of the arranged solution is maintained at a temperature at which the liquid crystalline solvent molecules form a liquid crystal phase, and the second functional molecular element is In the region to be formed, the liquid crystal solvent molecules are evaporated from the solution while maintaining the temperature of the arranged solution at a temperature at which the liquid crystal solvent molecules form a liquid phase, and the molecular stacking according to the concentration is performed. Forming a layer of the π-electron conjugated molecule on the surface of the electrode.   25. The method of manufacturing an integrated element according to claim 24, wherein the functional molecular device according to claim 11 or 12 is configured by the first functional molecular element.