Ambipolar polymer semiconductor thin films for ambipolar transistor and logic circuit

Abstract

The present invention relates to a bipolar polymer semiconductor thin film for a bipolar transistor and logic circuit, and a method for manufacturing a bipolar polymer semiconductor.

Description

Technology Field

[0001] The present invention relates to a bipolar polymer semiconductor thin film for a bipolar transistor and logic circuit, and a method for manufacturing a bipolar polymer semiconductor. Background Technology

[0002] An organic field-effect transistor (OFET) based on a donor-acceptor (DA) type polymer semiconductor is 1 cm 2 V 1 s 1 The above has received continuous attention due to the significantly enhanced charge carriers (μ). In addition to improving charge carriers, the alternating DA structure of polymer semiconductors enables bipolar charge transport by tuning energy levels to facilitate the efficient injection of electron and hole charge carriers from adjacent source and / or drain electrodes. Bipolar charge transport in single-component polymer semiconductor thin films can offer the advantage of easy fabrication for bipolar OFETs and logic circuits, including complementary metal-oxide semiconductor (CMOS) inverters. However, determining the ideal DA configuration for high electron and hole mobility with hysteresis-free transistor characteristics among numerous D and A moietyes requires significant effort through trial and error. Consequently, electron transport in DA-type polymer semiconductors has been limited despite reasonably deepened conduction band edge (CBE) energy levels. Prior art literature

[0003] Republic of Korea Registered Patent Publication No. 1933102. The problem to be solved

[0004] The present invention aims to provide a bipolar polymer semiconductor thin film for a bipolar transistor and logic circuit, and a method for manufacturing a bipolar polymer semiconductor.

[0005] However, the problems that this invention seeks to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below. means of solving the problem

[0006] The first aspect of the present invention provides a bipolar polymer semiconductor thin film for a transistor comprising a bipolar polymer semiconductor comprising a donor represented by the following chemical formula 1 and an acceptor represented by the following chemical formula 2 or 3, wherein the bipolar polymer semiconductor comprises a donor-acceptor-acceptor-donor moiety:

[0007] [Chemical Formula 1]

[0008] ,

[0009] [Chemical Formula 2]

[0010] ,

[0011] [Chemical Formula 3]

[0012] ,

[0013] In the above chemical formulas 1 and 3, R 1 and R 2 C, each independently, is linear or branched 1-30 It is an alkyl group, and X is H, F, Cl, Br, I, -CN, or -OCH3.

[0014] A second aspect of the present invention provides a transistor comprising a semiconductor layer including a bipolar polymer semiconductor thin film for a transistor according to a first aspect, wherein the semiconductor layer operates as an n-type and a p-type semiconductor.

[0015] A third aspect of the present invention comprises reacting a donor precursor and an acceptor precursor under a Pd catalyst to obtain a donor-acceptor intermediate compound; reacting the donor-acceptor intermediate compound with hexa-n-butylditin under a Pd catalyst to obtain a donor-acceptor-acceptor-donor intermediate compound; and reacting the donor-acceptor-acceptor-donor intermediate compound with N-bromosuccinimide to obtain a dibrominated donor-acceptor-acceptor-donor moiety. A method for manufacturing a bipolar polymer semiconductor comprises: a dibrominated donor-acceptor-acceptor-donor moiety and a hexa-n-butylditin reaction under a Pd catalyst to obtain a bipolar polymer semiconductor, wherein the bipolar polymer semiconductor comprises a donor represented by Formula 1 and an acceptor represented by Formula 2 or 3, and the bipolar polymer semiconductor comprises a donor-acceptor-acceptor-donor moiety.

[0016] The fourth aspect of the present invention provides a method for manufacturing a bipolar polymer semiconductor thin film for a transistor, comprising: obtaining a bipolar polymer semiconductor through a manufacturing method according to the third aspect; and mixing the bipolar polymer semiconductor with a solvent and performing a solution process to manufacture a bipolar polymer semiconductor thin film. Effects of the invention

[0017] A bipolar polymer semiconductor comprising a donor-acceptor-acceptor-donor moiety according to embodiments of the present invention and a bipolar polymer semiconductor thin film for a transistor comprising the same have improved electron and hole mobilities and a deepened conduction band edge (CBE) energy level compared to a polymer comprising a conventional donor-acceptor type moiety (donor-acceptor-donor-acceptor).

[0018] A transistor and a CMOS inverter (complementary metal-oxide semiconductor inverter) comprising a bipolar polymer semiconductor thin film for a transistor according to embodiments of the present invention as a semiconductor layer have excellent charge transport characteristics and hysteresis-free characteristics.

[0019] The CMOS inverter according to the embodiments of the present invention may exhibit a high gain of about 110 or more, or about 160 or more, as it has excellent charge transport characteristics.

[0020] The CMOS inverter according to the embodiments of the present invention includes a single layer of a bipolar polymer semiconductor thin film for the transistor as a channel layer, and thus, compared to a conventional CMOS inverter including n-type and p-type channels respectively, it has the characteristic of not requiring a complex patterning process during manufacturing. Brief explanation of the drawing

[0021] FIG. 1 shows the synthesis route of P1 (poly(4,4'-bis(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophene-2-yl)-7,7'-bi[1,2,5]thiadiazole[3,4-c]pyridine)) and P2 (poly(7,7'-bis(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophene-2-yl)-5,5'-difluoro-4,4'-bibenzo[c][1,2,5]thiadiazole)) in one embodiment of the present invention. FIG. 2 shows, in one embodiment of the present invention, (a) standardized UV-vis-NIR absorption spectra of P1 and P2 in a CF solution and a thin film; (b) calculated front and horizontal views of model trimers for P1 and P2 in a ground state; and (c and d) cyclic voltammetry curves (c) and energy level diagrams (d) of P1 and P2 (dashed lines represent VBE and CBE of PCDTPT (blue) and PCDTFBT (red), respectively). FIG. 3 is a GIWAXD reciprocal space map for thin films P1 and P2 before (pristine; P) and after (annealed; A) thermal annealing at an optimal temperature (240°C for P1, 160°C for P2) in one embodiment of the present invention, (b) IP(q xy ) and OOP(q z (c) a line-cut profile in the direction (orange box indicates an enlarged area of ​​the annealed P1 and P2 thin films); and (c) a schematic diagram of the crystal structure of P1 and P2 along with the associated molecular stacking distance. FIG. 4 shows AFM height images of thin films P1 and P2 before (P) and after (A) thermal annealing at an optimal temperature in one embodiment of the present invention (scale bar: 500 nm). FIG. 5 shows, in one embodiment of the present invention, (a) a device structure of an OFET; (b and c) transfer characteristics of a high-performance OFET fabricated from thin films P1(b) and P2(c) annealed at 240°C and 160°C, respectively; and (d) average μ of thin films P1 (blue) and P2 (red). h and μ e Value (scale bar is average μ h and μ e (ef) The output characteristics of the highest performance OFETs fabricated with P1(e) and P2(f) thin films annealed at 240°C and 160°C, respectively. FIG. 6 shows the transfer characteristics of an OFET prepared with thin films P1(a) and P2(b) before and after thermal annealing at various annealing temperatures in one embodiment of the present invention. FIG. 7 illustrates, in one embodiment of the present invention, (a) device structure and optical microscope image of an organic inverter (scale bar: 500 μm); (b) transfer characteristics and gain of a high-performance bipolar inverter fabricated from P1 annealed at 240°C (wherein the inverter is V DD = operated at 100 V); and (cd) V DD = This shows the transfer characteristics (c) and gain (d) of the inverter obtained at 60 V, 80 V, and 100 V. FIG. 8 shows, in one embodiment of the present invention, V DD = 40 V shows the transfer characteristics and gain of the inverter obtained at 40 V (a), an image (b) of the optimized inverter element, and a circuit diagram (c). Specific details for implementing the invention

[0022] Hereinafter, embodiments and examples of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments and examples described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0023] Throughout this specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "electrically connected" with other elements interposed between them.

[0024] Throughout this specification, when a component is described as being located "on" another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0025] Throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0026] Terms of degree used in this specification, such as “about,” “substantially,” etc., are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the stated meaning, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosure in which precise or absolute values ​​are mentioned to aid in understanding the invention.

[0027] The terms “step of” or “step of” as used throughout this specification do not mean “step for”.

[0028] Throughout this specification, the term “combination(s) of these” included in the Markush-type expression means one or more mixtures or combinations selected from the group consisting of the components described in the Markush-type expression, and means including one or more selected from the group consisting of said components.

[0029] Throughout this specification, the description of "A and / or B" means "A or B, or A and B".

[0030] Throughout this specification, the term “alkyl” or “alkyl group” comprises linear or branched alkyl groups having 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 8 carbon atoms, or 1 to 5 carbon atoms, and all possible isomers thereof. For example, the alkyl or alkyl group may be a methyl group (Me), an ethyl group (Et), an n-propyl group ( n Pr), iso-propyl group ( i Pr), n-butyl group ( n Bu), iso-butyl group ( iBu), tert-butyl group (tert-Bu, t Bu), sec-butyl group(sec-Bu, sec Bu), n-pentyl group ( n Pe), iso-pentyl group ( iso Pe), sec-pentyl group( sec Pe), tert-pentyl group( t Pe), neo-pentyl group( neo Examples include, but are not limited to, 3-pentyl groups, n-hexyl groups, iso-hexyl groups, heptyl groups, 4,4-dimethylpentyl groups, octyl groups, 2,2,4-trimethylpentyl groups, nonyl groups, decyl groups, undecyl groups, dodecyl groups, and isomers thereof.

[0032] Embodiments of the present invention have been described in detail below, but the present invention may not be limited thereto.

[0034] The first aspect of the present invention provides a bipolar polymer semiconductor thin film for a transistor comprising a bipolar polymer semiconductor comprising a donor represented by the following chemical formula 1 and an acceptor represented by the following chemical formula 2 or 3, wherein the bipolar polymer semiconductor comprises a donor-acceptor-acceptor-donor moiety:

[0035] [Chemical Formula 1]

[0036] ,

[0037] [Chemical Formula 2]

[0038] ,

[0039] [Chemical Formula 3]

[0040] ,

[0041] In the above chemical formulas 1 and 3, R 1 and R 2 C, each independently, is linear or branched 1-30 It is an alkyl group, and X is H, F, Cl, Br, I, -CN, or -OCH3.

[0042] In one embodiment of the present invention, the alkyl group is C 1-20 The alkyl group may be a linear alkyl group. For example, the alkyl group may be selected from a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, a octadecyl group, a nonadecyl group, an icosanyl group, and possible isomers thereof. In one embodiment of the present invention, the alkyl group is -C 16 H 33 It may be, but may not be limited to.

[0043] In one embodiment of the present invention, the bipolar polymer semiconductor may be represented by the following chemical formula 4 or 5:

[0044] [Chemical Formula 4]

[0045] ,

[0046] [Chemical Formula 5]

[0047] ,

[0048] In the above chemical formulas 4 and 5, R 1 and R 2 C, each independently, is linear or branched 1-30 It is an alkyl group, where X is H, F, Cl, Br, I, -CN, or -OCH3, and n and m are each integers from 3 to 200.

[0049] In one embodiment of the present invention, the bipolar polymer semiconductor may be represented by the following chemical formula 6 or 7:

[0050] [Chemical Formula 6]

[0051] ,

[0052] [Chemical Formula 7]

[0053] ,

[0054] In the above chemical formulas 6 and 7, n and m are each integers from 3 to 200.

[0055] In one embodiment of the present invention, in the above formulas 4 to 7, n and m may each be integers of 3 to 200, 3 to 150, 3 to 130, 8 to 200, 8 to 150, or 8 to 130.

[0056] In one embodiment of the present invention, the donor may include, but is not limited to, cyclopentadithiophene (CDT).

[0057] In one embodiment of the present invention, the acceptor may comprise, but is not limited to, pyridyl-2,1,3-thiadiazole (PT) or fluoro-2,1,3-benzothiadiazole (FBT).

[0058] In one embodiment of the present invention, the bipolar polymer semiconductor comprises a donor-acceptor-acceptor-donor moiety, and may have a conduction band edge (CBE) energy level that is more deepened compared to a polymer comprising a donor-acceptor moiety.

[0059] Throughout the entire specification, a polymer comprising a donor and an acceptor of the bipolar polymer semiconductor and comprising a donor-acceptor moiety is referred to as a counterpart of the bipolar polymer semiconductor. For example, if the donor is CDT and the acceptor is PT, the bipolar polymer semiconductor comprises a CDT-PT-PT-CDT moiety, and the counterpart of the bipolar polymer semiconductor may comprise a CDT-PT moiety.

[0060] In one embodiment of the present invention, the bipolar polymer semiconductor thin film for a transistor may have a deeper conduction band edge (CBE) energy level compared to a thin film comprising a polymer comprising a donor-acceptor moiety. A deeper CBE energy level means that the absolute value of the CBE energy level is larger.

[0061] In one embodiment of the present invention, the conduction band edge energy level value of the bipolar polymer semiconductor thin film for the transistor may be about 2 eV to about 5.5 eV. In one embodiment of the present invention, the conduction band edge energy level value of the bipolar polymer semiconductor thin film for the transistor may be about 2 eV to about 5.5 eV, about 2 eV to about 5 eV, about 2 eV to about 4.5 eV, about 2 eV to about 4 eV, about 2 eV to about 3.5 eV, or about 2 eV to about 3 eV.

[0062] In one embodiment of the present invention, the difference in energy levels of the conduction band edge (CBE) of the thin film comprising the polymer comprising the bipolar polymer semiconductor thin film for the transistor and the donor-acceptor moiety may be about 0.1 eV to about 2 eV.

[0063] In one embodiment of the present invention, the bipolar polymer semiconductor thin film for the transistor may be capable of efficient electron injection because the CBE energy level is deeper compared to a thin film comprising a counterpart of the bipolar polymer semiconductor (a polymer containing a donor-acceptor moiety).

[0064] In one embodiment of the present invention, the bipolar polymer semiconductor thin film for the transistor exists in a solid state, thereby having the characteristic of improving the interaction between polymer chains and achieving delocalization of electrons.

[0065] In one embodiment of the present invention, a bipolar polymer semiconductor thin film for a transistor comprising a donor represented by Formula 1 and an acceptor represented by Formula 2; or a bipolar polymer semiconductor represented by Formula 4 or 6 may first comprise an edge-on / face-on mixed crystal structure comprising an edge-on crystallite and a face-on crystallite, and accordingly, may have high electron and hole mobility.

[0066] In one embodiment of the present invention, the bipolar polymer semiconductor thin film for a transistor is at a temperature of about 80°C to about 300°C, about 80°C to about 270°C, about 80°C to about 240°C, about 80°C to about 200°C, about 80°C to about 160°C, about 100°C to about 300°C, about 100°C to about 270°C, about 100°C to about 240°C, about 100°C to about 200°C, about 100°C to about 160°C, about 130°C to about 300°C, about 130°C to about 270°C, about 130°C to about 240°C, about 130°C to about 200°C, about 130°C to about 160°C, about 200°C to about 300°C, about 200°C to about 200°C. It may be thermally annealed in a temperature range of 270°C, about 200°C to about 240°C, about 200°C to about 200°C, about 200°C to about 160°C, about 150°C to about 170°C, or about 230°C to about 250°C.

[0067] In one embodiment of the present invention, the crystallinity of the bipolar polymer semiconductor thin film for the transistor can be improved by thermal annealing.

[0069] A second aspect of the present invention provides a transistor comprising a semiconductor layer including a bipolar polymer semiconductor thin film for a transistor according to a first aspect, wherein the semiconductor layer operates as an n-type and a p-type semiconductor.

[0070] Detailed explanations have been omitted for parts that overlap with the first aspect of the present invention, but the content described in the first aspect of the present invention may be applied in the same way even if such explanations are omitted in the second aspect of the present invention.

[0071] In one embodiment of the present invention, the transistor may be a field-effect transistor.

[0072] In one embodiment of the present invention, the transistor may be an organic field-effect transistor (OFET) using an organic polymer as the gate dielectric, but is not limited thereto. In one embodiment of the present invention, the organic polymer may be used without limitation as long as it is an organic polymer that can be typically used as the gate dielectric of a transistor, and as a non-limiting example, it may be poly(methyl methacrylate) (PMMA).

[0073] In one embodiment of the present invention, the structure of the transistor may include, but is not limited to, a bottom-contact-top-gate (BCTG) type, a top-contact-bottom-gate (TCBG) type, a top-contact-top-gate (TCTG) type, or a bottom-contact-bottom-gate (BCBG) type.

[0074] In one embodiment of the present invention, the electron mobility of the transistor ( μ e ) is approximately 0.0001 cm 2 V-1 s -1 up to about 0.5 cm 2 V -1 s -1 It may be. In one embodiment of the present invention, the electron mobility of the transistor ( μ e ) is approximately 0.0001 cm 2 V -1 s -1 up to about 0.5 cm 2 V -1 s -1 , approximately 0.0001 cm 2 V -1 s -1 Up to about 0.45 cm 2 V -1 s -1 , approximately 0.0001 cm 2 V -1 s -1 Up to about 0.4 cm 2 V -1 s -1 , approximately 0.0001 cm 2 V -1 s -1 Up to about 0.35 cm 2 V -1 s -1 , approximately 0.0001 cm 2 V -1 s -1 Up to about 0.3 cm 2 V -1 s -1 , approximately 0.0001 cm 2 V -1 s -1 Up to about 0.25 cm 2 V -1 s -1 , approximately 0.0005 cm 2 V -1 s -1 up to about 0.5 cm 2 V -1 s -1 , approximately 0.0005 cm 2 V -1 s -1 Up to about 0.45 cm 2 V -1 s -1, approximately 0.0005 cm 2 V -1 s -1 Up to about 0.4 cm 2 V -1 s -1 , approximately 0.0005 cm 2 V -1 s -1 Up to about 0.35 cm 2 V -1 s -1 , approximately 0.0005 cm 2 V -1 s -1 Up to about 0.3 cm 2 V -1 s -1 , approximately 0.0005 cm 2 V -1 s -1 Up to about 0.25 cm 2 V -1 s -1 , approximately 0.001 cm 2 V -1 s -1 up to about 0.5 cm 2 V -1 s -1 , approximately 0.001 cm 2 V -1 s -1 Up to about 0.45 cm 2 V -1 s -1 , approximately 0.001 cm 2 V -1 s -1 Up to about 0.4 cm 2 V -1 s -1 , approximately 0.001 cm 2 V -1 s -1 Up to about 0.35 cm 2 V -1 s -1 , approximately 0.001 cm 2 V -1 s -1 Up to about 0.3 cm 2 V -1 s -1 , or about 0.001 cm 2 V -1 s-1 Up to about 0.25 cm 2 V -1 s -1 It could be.

[0075] In one embodiment of the present invention, the electron mobility of a transistor comprising, as a semiconductor layer, a bipolar polymer semiconductor thin film for a transistor comprising a donor represented by Formula 1 and an acceptor represented by Formula 2; or a bipolar polymer semiconductor represented by Formula 4 or 6, is about 0.2 cm 2 V -1 s -1 up to about 0.5 cm 2 V -1 s -1 , about 0.2 cm 2 V -1 s -1 Up to about 0.45 cm 2 V -1 s -1 , about 0.2 cm 2 V -1 s -1 Up to about 0.41 cm 2 V -1 s -1 , about 0.2 cm 2 V -1 s -1 Up to about 0.40 cm 2 V -1 s -1 , about 0.2 cm 2 V -1 s -1 Up to about 0.35 cm 2 V -1 s -1 , about 0.25 cm 2 V -1 s -1 up to about 0.5 cm 2 V -1 s -1 , about 0.25 cm 2 V -1 s -1 Up to about 0.45 cm 2 V -1 s -1, about 0.25 cm 2 V -1 s -1 Up to about 0.41 cm 2 V -1 s -1 , about 0.25 cm 2 V -1 s -1 Up to about 0.40 cm 2 V -1 s -1 , about 0.25 cm 2 V -1 s -1 Up to about 0.35 cm 2 V -1 s -1 , approximately 0.28 cm 2 V -1 s -1 up to about 0.5 cm 2 V -1 s -1 , approximately 0.28 cm 2 V -1 s -1 Up to about 0.45 cm 2 V -1 s -1 , approximately 0.28 cm 2 V -1 s -1 Up to about 0.41 cm 2 V -1 s -1 , approximately 0.28 cm 2 V -1 s -1 Up to about 0.40 cm 2 V -1 s -1 , approximately 0.28 cm 2 V -1 s -1 Up to about 0.35 cm 2 V -1 s -1 , about 0.3 cm 2 V -1 s -1 up to about 0.5 cm 2 V -1 s -1 , about 0.3 cm 2 V -1 s -1Up to about 0.45 cm 2 V -1 s -1 , about 0.3 cm 2 V -1 s -1 Up to about 0.41 cm 2 V -1 s -1 , about 0.3 cm 2 V -1 s -1 Up to about 0.40 cm 2 V -1 s -1 , or about 0.3 cm 2 V -1 s -1 Up to about 0.35 cm 2 V -1 s -1 It could be.

[0076] In one embodiment of the present invention, the hole (h) mobility of the transistor ( μ h ) is approximately 0.001 cm 2 V -1 s -1 to about 1.5 cm 2 V -1 s -1 It may be. In one embodiment of the present invention, the hole mobility of the transistor ( μ h ) is approximately 0.001 cm 2 V -1 s -1 to about 1.5 cm 2 V -1 s -1 , approximately 0.001 cm 2 V -1 s -1 to about 1.4 cm 2 V -1 s -1 , approximately 0.001 cm 2 V -1 s -1 Up to about 1.3 cm 2 V -1 s -1 , approximately 0.002 cm 2 V -1 s-1 to about 1.5 cm 2 V -1 s -1 , approximately 0.002 cm 2 V -1 s -1 to about 1.4 cm 2 V -1 s -1 , approximately 0.002 cm 2 V -1 s -1 Up to about 1.3 cm 2 V -1 s -1 , approximately 0.003 cm 2 V -1 s -1 to about 1.5 cm 2 V -1 s -1 , approximately 0.003 cm 2 V -1 s -1 to about 1.4 cm 2 V -1 s -1 , or about 0.003 cm 2 V -1 s -1 Up to about 1.3 cm 2 V -1 s -1 It could be.

[0077] In one embodiment of the present invention, the hole mobility of a transistor comprising, as a semiconductor layer, a bipolar polymer semiconductor thin film for a transistor comprising a donor represented by Formula 1 and an acceptor represented by Formula 2; or a bipolar polymer semiconductor represented by Formula 4 or 6, is about 0.5 cm 2 V -1 s -1 to about 1.5 cm 2 V -1 s -1 , about 0.5 cm 2 V -1 s -1 to about 1.4 cm 2 V -1 s -1, about 0.5 cm 2 V -1 s -1 to about 1.35 cm 2 V -1 s -1 , about 0.8 cm 2 V -1 s -1 to about 1.5 cm 2 V -1 s -1 , about 0.8 cm 2 V -1 s -1 to about 1.4 cm 2 V -1 s -1 , about 0.8 cm 2 V -1 s -1 to about 1.35 cm 2 V -1 s -1 , about 0.9 cm 2 V -1 s -1 to about 1.5 cm 2 V -1 s -1 , about 0.9 cm 2 V -1 s -1 to about 1.4 cm 2 V -1 s -1 , about 0.9 cm 2 V -1 s -1 to about 1.35 cm 2 V -1 s -1 , about 1 cm 2 V -1 s -1 to about 1.5 cm 2 V -1 s -1 , about 1 cm 2 V -1 s -1 to about 1.4 cm 2 V -1 s -1 , or about 1 cm 2 V -1 s -1 to about 1.35 cm 2V -1 s -1 It could be.

[0078] In one embodiment of the present invention, the transistor may have high electron and hole mobility with improved electron and hole transport characteristics compared to a transistor comprising a polymer thin film comprising a counterpart of the bipolar polymer semiconductor as a semiconductor layer.

[0079] In one embodiment of the present invention, the transistor may have hysteresis-free characteristics.

[0080] In one embodiment of the present invention, the transistor may be used in an inverter or a DC-AC converter, but is not limited thereto.

[0081] In one embodiment of the present invention, the inverter may include a CMOS (complementary metal-oxide semiconductor) inverter, but may not be limited thereto.

[0082] In one embodiment of the present invention, the inverter may be used in an inverse logic circuit (NAND) or an inverse logic OR circuit (NOR).

[0083] In one embodiment of the present invention, the CMOS inverter comprises a bipolar polymer semiconductor thin film for a transistor according to the first aspect as a channel layer material, wherein the channel layer may operate as an n-type and a p-type channel.

[0084] In one embodiment of the present invention, the CMOS inverter includes a single layer of a bipolar polymer semiconductor thin film for the transistor as a channel layer, so compared to a conventional CMOS inverter including n-type and p-type channels, it has the characteristic of not requiring a complex patterning process during manufacturing.

[0085] In one embodiment of the present invention, the CMOS inverter, when the dielectric thickness is about 600 nm to about 700 nm and the width ratio of p-type and n-type transistors is about 1:1, has a supply voltage (V DD ) is V DD = When V is about 100, the gain (G) value can be about 90 to about 110 or about 100 to about 110.

[0086] In one embodiment of the present invention, the CMOS inverter has a dielectric thickness of about 300 nm to about 400 nm and a width ratio of p-type to n-type transistors of about 1:4, wherein the supply voltage is V DD = When V is about 40, the gain (G) value can be about 150 or more, about 160 or more, or about 160 to about 180.

[0088] A third aspect of the present invention comprises reacting a donor precursor and an acceptor precursor under a Pd catalyst to obtain a donor-acceptor intermediate compound; reacting the donor-acceptor intermediate compound with hexa-n-butylditin under a Pd catalyst to obtain a donor-acceptor-acceptor-donor intermediate compound; and reacting the donor-acceptor-acceptor-donor intermediate compound with N-bromosuccinimide to obtain a dibrominated donor-acceptor-acceptor-donor moiety. A method for manufacturing a bipolar polymer semiconductor comprises: a dibrominated donor-acceptor-acceptor-donor moiety and a hexa-n-butylditin, wherein the hexa-n-butylditin is subjected to a Stille reaction under a Pd catalyst to obtain a bipolar polymer semiconductor, wherein the bipolar polymer semiconductor comprises a donor represented by the following Chemical Formula 1 and an acceptor represented by the following Chemical Formula 2 or 3, and wherein the bipolar polymer semiconductor comprises a donor-acceptor-acceptor-donor moiety.

[0089] [Chemical Formula 1]

[0090] ,

[0091] [Chemical Formula 2]

[0092] ,

[0093] [Chemical Formula 3]

[0094] ,

[0095] In the above chemical formulas 1 and 3, R 1 and R 2 C, each independently, is linear or branched 1-30 It is an alkyl group, and X is H, F, Cl, Br, I, -CN, or -OCH3.

[0096] Detailed explanations have been omitted for parts that overlap with the first aspect of the present invention, but the content described in the first aspect of the present invention may be applied in the same way even if such explanations are omitted in the third aspect of the present invention.

[0097] In one embodiment of the present invention, the manufacturing method may be performed in the presence of a solvent. In one embodiment of the present invention, the solvent may be an organic solvent including toluene, tetrahydrofuran (THF), chloroform (CF), chlorobenzene (CB), or xylene, or water, but is not limited thereto.

[0098] In one embodiment of the present invention, the Pd catalyst may include Pd(PPh3)4, but is not limited thereto.

[0099] In one embodiment of the present invention, the donor moiety precursor may comprise 4,4-Dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)trimethylstannane.

[0100] In one embodiment of the present invention, the acceptor moiety may comprise 4,7-dibromo-[1,2,5]thiadiazolo[3,4-c]pyridine or 4,7-dibromo-5-fluorobenzo[c][1,2,5]thiadiazole.

[0101] In one embodiment of the present invention, obtaining the donor-acceptor-acceptor-donor intermediate compound may be carried out by dissolving the donor-acceptor intermediate compound, hexa-n-butylditin, and Pd catalyst in toluene and then performing a Stille reaction while stirring.

[0102] In one embodiment of the present invention, obtaining the donor-acceptor-acceptor-donor intermediate compound may be performed at a temperature range of about 100°C to about 12°C for about 1 day to about 12 days, about 1 day to about 11 days, about 7 days to about 12 days, or about 7 days to about 11 days, but is not limited thereto.

[0103] In one embodiment of the present invention, obtaining the brominated donor-acceptor-acceptor-donor moiety may be carried out by dissolving the donor-acceptor-acceptor-donor intermediate compound and N-bromosuccinimide (NBS) in tetrahydrofuran (THF) and then reacting by stirring.

[0104] In one embodiment of the present invention, obtaining the ebromified donor-acceptor-acceptor-donor moiety may be performed for about 1 to about 3 days under room temperature and dark room conditions.

[0105] In one embodiment of the present invention, obtaining the bipolar polymer semiconductor may be carried out by dissolving the dibrominated donor-acceptor-acceptor-donor moiety, hexa-n-butylditin, and Pd catalyst in toluene and performing a Stille reaction while stirring.

[0106] In one embodiment of the present invention, obtaining the bipolar polymer semiconductor may be performed at a temperature range of about 100°C to about 120°C for about 1 hour to about 5 hours, about 1 hour to about 3 hours, about 2 hours to about 5 hours, or about 2 hours to about 3 hours.

[0107] In one embodiment of the present invention, in the method for manufacturing the bipolar polymer semiconductor, the reaction may be carried out under an argon atmosphere, a nitrogen atmosphere, or an atmosphere.

[0108] In one embodiment of the present invention, the method for manufacturing the bipolar polymer semiconductor may further include washing, filtering, extracting, concentrating, and / or drying the product.

[0109] In one embodiment of the present invention, the method for manufacturing the bipolar polymer semiconductor comprises a series of steps, wherein the donor-acceptor intermediate compound is first obtained, and the donor-acceptor intermediate compound is subjected to a Stille reaction to obtain the donor-acceptor-acceptor-donor intermediate compound. In particular, the method has the advantage of solving the problems of steric hindrance and isomer formation that may occur when the acceptor moiety precursor contains a halogen group (F) in the side chain, and obtaining the product in a high yield.

[0110] In one embodiment of the present invention, the yield of the bipolar polymer semiconductor may be about 40% or more, about 45% or more, about 50% or more, about 60% or more, about 70% or more, or about 80% or more.

[0112] The fourth aspect of the present invention provides a method for manufacturing a bipolar polymer semiconductor thin film for a transistor, comprising: obtaining a bipolar polymer semiconductor through a manufacturing method according to the third aspect; and mixing the bipolar polymer semiconductor with a solvent and performing a solution process to manufacture a bipolar polymer semiconductor thin film.

[0113] In one embodiment of the present invention, the method for manufacturing the bipolar polymer semiconductor thin film for a transistor comprises: the bipolar polymer semiconductor thin film at about 80°C to about 300°C, about 80°C to about 270°C, about 80°C to about 240°C, about 80°C to about 200°C, about 80°C to about 160°C, about 100°C to about 300°C, about 100°C to about 270°C, about 100°C to about 240°C, about 100°C to about 200°C, about 100°C to about 160°C, about 130°C to about 300°C, about 130°C to about 270°C, about 130°C to about 240°C, about 130°C to about 200°C, about 130°C to about 160°C, about 200°C to about 300°C, It may additionally include thermal annealing in a temperature range of about 200°C to about 270°C, about 200°C to about 240°C, about 200°C to about 200°C, about 200°C to about 160°C, about 150°C to about 170°C, or about 230°C to about 250°C.

[0115] The present invention will be explained in more detail below using examples, but the following examples are merely illustrative to aid in understanding the present invention, and the content of the present invention is not limited to the following examples.

[0117] [Example]

[0118] 1. Experiment

[0119] 1) Synthesis and Characterization

[0120] All starting materials were purchased from Sigma-Aldrich or Acros and used without purification. Unless otherwise specified, all solvents are ACS grade. 4,4-Dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)trimethylstannane M1 ), 4,7-dibromo-[1,2,5]thiadiazolo[3,4-c]pyridine (4,7-dibromo-[1,2,5]thiadiazolo[3,4-c]pyridine)( M2 ), 7-bromo-4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-[1,2,5]thiadiazolo[3,4-c]pyridine (7-bromo-4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-[1,2,5]thiadiazolo[3,4-c]pyridine)( M3 ), 4,7-dibromo-5-fluorobenzo[c][1,2,5]thiadiazole (4,7-dibromo-5-fluorobenzo[c][1,2,5]thiadiazole)( M4 ), and 4-bromo-7-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-5-fluorobenzo[c][1,2,5]thiadiazole ( M5 ) was synthesized according to conventional research.

[0121] 4,4'-bis(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-7,7'-bi[1,2,5]thiadiazolo[3,4-c]pyridine (4,4'-bis(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-7,7'-bi[1,2,5]thiadiazolo[3,4-c]pyridine)( Compound 1 Synthesis of )

[0122] first, M3 (7.38 g, 8.77 mmol), Pd(PPh3)4 (0.30 g, 0.263 mmol), and hexa-n-butylditin (2.42 g, 4.18 mmol) were dissolved in anhydrous toluene (150 mL) under an argon atmosphere. Secondly, the reaction mixture was stirred at 110°C for 7 days. After cooling to room temperature, the toluene was removed under reduced pressure. The mixture was extracted with dichloromethane (DCM; 100 mL, 5 times) and deionized water (300 mL), dried with anhydrous MgSO4, and filtered. The initial product was concentrated under reduced pressure and purified by silica gel chromatography (eluent: hexane / DCM in a volume ratio of 100 / 0 to 70 / 30) to obtain a dark blue oil (4.34 g, 59%).

[0123] 4,4'-bis(6-bromo-4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-7,7'-bi[1,2,5]thiadiazolo[3,4-c]pyridine Compound 2 Synthesis of )

[0124] Compound 1 (3.50 g, 2.30 mmol) and NBS (0.90 g, 5.06 mmol) were dissolved in 150 mL of anhydrous THF under argon. The solution was stirred at room temperature under dark conditions for 48 hours. The mixture was poured into water (80 mL) and extracted with DCM (100 mL three times), then dried with MgSO4 and filtered. The initial mixture was concentrated under reduced pressure and purified by silica gel chromatography (eluent: hexane / DCM in a volume ratio of 100 / 0 to 40 / 60) to obtain a dark-blue oil (2.30 g, 60%).

[0125] 7,7'-bis(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-5,5'-difluoro-4,4'-bibenzo[c][1,2,5]thiadiazole Compound 3 Synthesis of )

[0126] first, M5(3.95 g, 4.60 mmol), Pd(PPh3)4 (0.16 g, 0.14 mol), and hexa-n-butylditin (1.21 g, 2.09 mmol) were dissolved in anhydrous toluene (100 mL) under an argon atmosphere. The reaction mixture was stirred at 110°C for 11 days. After cooling to room temperature, the toluene was removed under reduced pressure. The mixture was extracted with DCM (6 times with 100 mL) and deionized water (300 mL), dried with anhydrous MgSO4, and filtered. The initial mixture was concentrated under reduced pressure and purified by silica gel chromatography (eluent: hexane / DCM in a volume ratio of 100 / 0 to 65 / 35) to obtain a dark-red oil (1.07 g, 29%).

[0127] 7,7'-bis(6-bromo-4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-5,5'-difluoro-4,4'-bibenzo[c][1,2,5]thiadiazole ( Compound 4 Synthesis of )

[0128] Compound 3 (0.80 g, 0.51 mmol) and NBS (0.20 g, 1.13 mmol) were dissolved in 50 mL of anhydrous THF under argon. The solution was stirred at room temperature under dark conditions for 48 hours. The mixture was poured into water (80 mL) and extracted with DCM (3 times with 100 mL), then dried with MgSO4 and filtered. The initial mixture was concentrated under reduced pressure and purified by silica gel chromatography (eluent: hexane / DCM in a volume ratio of 100 / 0 to 80 / 20) to obtain a dark red oil (0.72 g, 82%).

[0129] Poly(4,4'-bis(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-7,7'-bi[1,2,5]thiadiazolo[3,4-c]pyridine)( P1 Synthesis of )

[0130] Compound 2(170 mg, 0.10 mol), hexa-n-butylditin (58.6 mg, 0.10 mmol), Pd(PPh3)4 (3.51 mg, 3.04 μmol), and toluene (20 mL) were added to a shrink tube. The reaction mixture was stirred under argon at 110 °C for 2 hours. The initial product was precipitated in methanol (300 mL). The resulting solid was filtered, and the low molecular weight fraction was removed by Soxhlet extraction sequentially using methanol (24 hours), acetone (24 hours), and hexane (24 hours). The residue was extracted with CF, precipitated with methanol, and dried in a vacuum oven to obtain a dark green product. Separation yield = 81% (138 mg). M n = 89.4 kg / mol, weight-average molecular weight( M w ) = 319 kg / mol, PDI = 3.57

[0131] Poly(7,7'-bis(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-5,5'-difluoro-4,4'-bibenzo[c][1,2,5]thiadiazole)( P2 Synthesis of )

[0132] Compound 4 (200mg, 0.12mmol), hexa -n- Butylditin (67.7 mg, 0.12 mmol), Pd(PPh3)4 (2.03 mg, 3.50 μmol), and toluene (20 mL) were added to a Schlenk tube. The reaction mixture was stirred under argon at 110 °C for 3 hours. The initial product was precipitated in methanol (300 mL). The resulting solid was filtered and subjected to Soxhlet extraction sequentially with methanol (24 hours), acetone (24 hours), and hexane (24 hours) to remove the low molecular weight fraction. The residue was extracted with CF, precipitated with methanol, and dried in a vacuum oven to obtain a dark green product. Separation yield = 45% (89 mg). M n = 48 kg / mol, M w = 84 kg / mol, PDI = 1.74.

[0133] 2) Ultraviolet-Visible-Near Infrared Spectroscopy

[0134] Ultraviolet-visible-near-infrared (UV-vis-NIR) absorption spectra were measured at room temperature (25°C) using a UV-vis-NIR spectrophotometer (V-770, Jasco Inc.). The solution was prepared by mixing P1 and P2 in CF solvent (25 μg mL). -1 P1 and P2 thin films were prepared by dissolving in ) and ). P1 and P2 thin films were prepared by dissolving in CF solution (5 mg mL). -1 ) was spin-coated onto a quartz substrate.

[0135] 3) Cyclic Voltammetry

[0136] Cyclic voltammetry (CV) measurements were performed at 100 mV s⁻¹ at room temperature under argon. -1 It was performed at an electrochemical station (METEK, Versa STAT3 Inc.) using a 3-electrode cell system with a 0.1 M tetra-n-butylammonium hexafluorophosphate (n-Bu4NPF6) solution dissolved in acetonitrile at a scan rate of Ag / Ag + An electrode, a platinum wire, and a glassy carbon disk were used as the reference electrode, counter electrode, and working electrode, respectively. The reference electrode was calibrated using a ferrocene / ferrocenium redox couple as an external standard, and the oxidation potential was set to -4.8 eV relative to the vacuum level. The VBE and CBE energy levels were referenced from previous studies.

[0137] 4) Density Functional Theory Calculations

[0138] Density functional theory (DFT) calculations were performed using the Gaussian 16W package containing the non-local hybrid Becke 3-parameter Lee-Yang-Parr (B3LYP) function and the 6-31G basis set, and the VBE and CBE energy levels were described after optimizing the geometry of P1 and P2 dimers using the same method.

[0139] 5) Gel Permeation Chromatography

[0140] M of P1 and P2 n , M w , and PDI were determined using a gel permeation chromatography (GPC) system (1200S, Agilent Inc.). A series of monodisperse polystyrenes dissolved in THF (HPLC grade) at room temperature were used as standards.

[0141] 6) Grazing-Incidence Wide-Angle X-ray Diffraction

[0142] GIWAXD (2D Grazing Incident Wide-Angle X-ray Diffraction) measurements were performed at the 9A U-SAXS beamline of the Pohang Accelerator Laboratory in Korea. X-rays from the vacuum undulator were monochromated at an incident angle of 0.12° (E = 11.08 keV). The GIWAXD patterns were recorded using a 2D CCD detector (MX170-HS, Rayonix Inc.). The detector was positioned approximately 210 mm from the center of the sample.

[0143] 7) Atomic Force Microscopy

[0144] Atomic force microscope (AFM) height images of the P1 and P2 thin films were obtained using an AFM instrument (Cypher S, Oxford Instruments) before and after thermal annealing. Root-mean-square (RMS) values ​​were determined using built-in software.

[0145] 8) Device Fabrication and Characterization

[0146] For organic field-effect transistors (OFETs), the Ni (5 nm) / Au (50 nm) source and drain electrodes are n ++ Patterned on a Si (500 μm) / silicon dioxide (SiO2, 300 nm) substrate according to a conventional photolithography process. Subsequently, the substrate was sequentially washed in a sonication bath with acetone and isopropanol for 10 minutes each. The washed substrate was stored overnight in a drying oven at 100°C. The P1 and P2 thin films were pre-washed n ++ Chlorobenzene solution (5 mg mL) on a Si / SiO2 substrate -1 Spin-coated with a poly(methyl methacrylate) (PMMA) solution. The poly(methyl methacrylate) solution was butyl acetate solution (80 mg mL). -1 Spin-coated from ). In particular, for the annealed device, the P1 and P2 thin films were annealed at 240°C and 160°C, respectively, in a nitrogen-filled glove box before spin-coating the PMMA gate dielectric. The PMMA thin films were heat-cured at 80°C for 2 hours in a nitrogen-filled glove box. Finally, the Al (50 nm) gate electrode was placed in a high vacuum (approx. 3×10⁻⁶). -6 It was deposited through a shadow mask by thermal evaporation under Torr. A CMOS (Complementary Metal-Oxide Semiconductor) inverter was fabricated using the same process, but a different shadow mask was used than that used in the OFET fabrication process. All device parameters were recorded using a semiconductor parameter analyzer (4200A-SCS, Keithley Co. Ltd.) in a nitrogen-filled glove box. The channel width is 1000 μm, and the channel lengths are 20 μm and 40 μm. In the structure of the inverter of one embodiment, both the p-channel and n-channel have a channel width of 1000 μm and a channel length of 20 μm ( Insertion of FIG. 7a and b The structure of the inverter of another embodiment has a channel length of 20 μm for both the p-channel and n-channel, but the channel width is 200 μm for the p-channel and 800 μm for the n-channel, having a ratio of 1:4 ( Figures 8b and c ).

[0148] 2. Results and Discussion

[0149] 1) Synthesis and Characterization

[0150] P1 was prepared according to the synthesis route shown in Fig. 1. In addition, another donor-acceptor-acceptor-donor (DAAD) type polymer semiconductor (hereinafter referred to as PCFFC (P2)) was prepared using fluoro-2,1,3-benzothiadiazole (FBT) as the A moiety to investigate the applicability of the design strategy of the present invention to various donor-acceptor (DA) combinations. To this end, 7-bromo-4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophene-2-yl)-[1,2,5]thiadiazolo[3,4-c]pyridine (CDT-PT-Br)( M3 ) and 4-bromo-7-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophene-2-yl)-5-fluorobenzo[c][1,2,5]thiadiazole(CDT-FBT-Br)( M5) according to conventional reported procedures 4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)trimethylstannane ( M1 ), 4,7-dibromo-[1,2,5]thiadiazolo[3,4-c]pyridine ( M2 ), and 4,7-dibromo-5-fluorobenzo[c][1,2,5]thiadiazole ( M4 Compound 1 (CDT-PT-PT-CDT) and Compound 3 (CDT-FBT-FBT-CDT) were obtained using M3 or M5 and hexa-n-butylditin (hexa- n Compound 3 was prepared by a Pd-mediated Stille coupling reaction between the two (-butylditin). In particular, compound 3 required a longer reaction time (more than 10 days) than compound 1 and exhibited a lower yield (<22%) due to steric hindrance caused by bulky fluorine atoms in the FBT moiety.

[0151] Subsequently, compounds 1 and 3 were converted into the dibrominated monomer compounds 2 (Br-CDT-PT-PT-CDT-Br) and 4 (Br-CDT-FBT-FBT-CDT-Br), respectively, using N-bromosuccinimide (NBS) under dark conditions. Finally, monomers 2 and 4 were converted into hexa-n-butylditin (hexa- nStile polymerization was performed using (-butylditin) to obtain the final products P1 and P2 in satisfactory yields (over 80%), respectively. The resulting polymers P1 and P2 exhibited excellent room-temperature solubility in various organic solvents such as tetrahydrofuran (THF), chloroform (CF), chlorobenzene (CB), and xylene. The number-average molecular weight (M) of P1 and P2. n The ) values ​​were measured by gel permeation chromatography (GPC) as 89 kg / mol and 48 kg / mol, respectively. The corresponding polydispersity index (PDI) was 3.57 and 1.74. M of P2 n M of P1 is likely due to the steric hindrance of monomer 4. n Although less (discussed later), P2's M n It is sufficiently high for efficient charge transport in the solid state.

[0153] 2) Optical and electrochemical properties

[0154] The optical properties of P1 and P2 in diluted solution and thin film states were investigated using ultraviolet-visible-near-infrared (UV-vis-NIR) absorption spectroscopy ( a of Fig. 2The detailed parameters are summarized in Table 1 below. All solutions and thin films exhibited dual-band absorption, typically observed in donor-accept (DA) type conjugated molecules, involving electronic transitions to the intramolecular charge transfer (ICT) state at wavelengths (λ) greater than 500 nm. The bandwidth of the P1 thin film increased compared to that of the P1 solution. The broader spectral band of the P1 thin film is attributed to enhanced 0-0 mode transitions at a wavelength of approximately λ ≈ 900 nm, resulting in improved interchain interactions and delocalization of π electrons in the solid state.

[0155] Compared to P1, the P2 solution and thin film exhibited a hypochromic shift in the absorption spectrum, resulting in a significant increase in the bandgap of P2. The maximum wavelength (λ) of the P2 solution and thin film max ) were 631 nm and 636 nm, respectively. λ between the solution and the thin film of P1 and P2 max Difference (Δλ max ) were found to be approximately 150 nm and approximately 148 nm, respectively. At the same time, considering that deepened valence band edge (VBE) and CBE energy levels are expected in fluorinated acceptor-containing polymer semiconductors without abrupt changes in the optical bandgap, the optical bandgap of P2 (E g ≈ 1.74 eV) is P1(E g The significant increase compared to ≈ 1.20 eV is an unexpected result.

[0156] Since the shortwave chromatic shift and the consequently increased bandgap of DA-type polymer semiconductors can be induced by inefficient electronic transitions to the ICT state due to distortion of π-conjugation, the backbone coplanarity of P1 and P2 was investigated at the B3LYP / 6-31G level using density functional theory (DFT) calculations ( Figure 2b ). In DFT calculations performed on the dimers of P1 and P2, the hexadecyl side chain was replaced with a methyl group for simplification. The optimized configuration for P1 showed a significantly small dihedral torsional angle (<0.01°), whereas P2 exhibited a relatively large angle (~47°) between the FBT moiety. This large distortion is attributed to the steric repulsion between the fluorine atoms of the FBT moiety. Therefore, the band gap of P2 is compared to that of P1 and its DA-type counterpart, poly(cyclopenta[1,2-b:5,4-b']dithiophene-fluorobenzo[c][1,2,5]thiadiazole (PCDTFBT) ( E It was found to be larger than that of g ≈ 1.32 eV. These results demonstrate the importance of the type and position of substituted atoms in the A moiety of DAAD-type bipolar polymer semiconductors.

[0157] In addition to the results of UV-vis-NIR absorption spectroscopy, the VBE and CBE energy levels of P1 and P2 were determined using cyclic voltammetry (CV). c of Fig. 2 ). For reference, redox-coupled ferrocene / ferrocenium (Fc / Fc +Compared to an internal standard using ), P1 and P2 exhibited reversible oxidation and reduction characteristics in cathodic and anode scans, respectively. Measurements and calculations were performed according to conventional studies. Detailed parameters are summarized in Table 1 below. The VBE / CBE energy levels of P1 and P2 are CV (for VBE) and UV-vis-NIR (E g Based on the results (in the case of), they were found to be -5.28 / -4.08 eV and -5.24 / -3.50 eV, respectively. d of Fig. 2 The energy levels obtained from DFT calculations are the aforementioned experimental data ( Table 1 It was in good agreement with ). Since the CBE energy level of DAAD type P1 is deeper than the CBE energy level of P2 and its DA type counterpart (e.g., PCDTPT), efficient electron injection from the Au electrode can be expected in P1-based OFET devices compared to P2 and PCDTPT-based devices.

[0158] Polymer UV-vis-NIR CV DFT l max (nm) a l max (nm) b TO g opt (house) c TO VBE (house) d TO CBE (house) d TO g CV (house) e TO HOMO (house) TO LUMO (house) TO g (house) P1 781 784 1.20 -5.28 -3.41 1.87 -5.32 -3.95 1.37 P2 631 636 1.74 -5.24 -3.33 1.91 -5.33 -3.60 1.73

[0160] 3) Crystal structure

[0161] To investigate the crystal structure and order of the P1 and P2 thin films, two-dimensional grazing incidence wide-angle X-ray diffraction (GIWAXD) experiments were performed on pristine (P) and annealed (A) P1 and P2 thin films. In particular, the optimal annealing temperature was determined to be the temperature that resulted in the highest μ value for each OFET device (discussed later). a of Fig. 3 shows reciprocal space maps for pristine and annealed P1 and P2 thin films, and Figure 3b is in-plane (IP); q xy ) and out-of-plane (OOP); q zShows the corresponding line-cut profile according to the direction. Table 2 [Figure] shows detailed crystallographic parameters. The pristine P1 thin film exhibited diffraction peaks corresponding to higher-order crystal structures with a preferential edge-on configuration. Diffraction peaks up to the fourth order in the OOP direction indicate well-ordered edge-on crystallites. After thermal annealing at 240°C, the intensity of the crystal peaks increased, indicating more ordered polymer crystallites. Interestingly, the P1 thin film also exhibited face-on crystallites with a weak (010) diffraction peak in the OOP direction. Since the mixed edge-on / face-on crystal structure observed in P1 is known to enhance charge transport of electrons and holes through the three-dimensional network of polymer crystallites, the electron and hole mobility of P1 is expected to be improved compared to P2 and PCDTPT.

[0162] Polymer Thermal Annealing(°C) In-Plane (Å) Out-of-Plane (Å) d (100) L c(100) d (010) L c(010) d (200) a L c(200) d (010) L c(010) P1 - 27.12 84.06 3.57 37.04 25.87 73.36 3.58 24.49 P2 - 25.11 50.57 - - - - - - P1 240 28.05 101.47 3.56 66.49 26.17 97.00 3.55 31.08 P2 160 25.39 53.66 3.88 78.97 25.70 111.32 - -

[0164] In contrast, the pristine P2 thin film did not exhibit noticeable crystal peaks. After thermal annealing at 160°C, edge-on crystals were formed in the P2 thin film. However, interestingly, the π-π stacking distance (d) of the edge-on crystallites in the annealed P2 thin film π-π )(3.88 Å) is that of the annealed P1 thin film (d π-π It was significantly larger than = 3.56 Å. The enhanced π-π stacking distance of edge-on crystallites in the annealed P2 thin film is attributed to the non-coplanar backbone structure of the CDT-FBT-FBT-CDT framework and the consequent undesirable stacking of P2 polymer chains ( Figure 2b ). Therefore, the lamellar stacking distance of P2 (lamellar stacking distance; d(100) )(25.75 Å) is, c of Fig. 3 As shown in, P1(d (100) It decreased slightly compared to (= 26.50 Å). The higher-order alignment and stacking characteristics of P1 compared to P2 were confirmed by atomic force microscopy (AFM) results, revealing well-aligned nanocrystals in the P1 thin film ( Fig. 4 ).

[0166] 4) Electrical characteristics

[0167] To investigate the electrical characteristics of P1 and P2, an OFET with a bottom-contact-top-gate configuration was fabricated using poly(methyl methacrylate) (PMMA) as the gate dielectric. a of Fig. 5 and Table 3 ). Figures 5b and c This shows the transfer characteristics of the highest performance device fabricated with P1 and P2 charge transport layers annealed at 240°C and 160°C, respectively. Figure 6 and Table 4 Figures 1 and 2 show the transfer characteristics of P1 and P2 and the corresponding device parameters as a function of annealing temperature, respectively. The device fabricated with the annealed P1 thin film is 1.10 ± 0.23 cm 2 V -1 s -1 and 0.28 ± 0.05 cm 2 V -1 s -1 The average μ h and μ e represented the value ( d of Fig. 5 ). The highest μ of P1 h and μ e The value is 1.50 cm each 2 V -1 s -1 and 0.41 cm 2 V -1 s -1...and this value is approximately twice as large as the value of the previously reported DA-type PCDTPT. In particular, the P1 device exhibits hysteresis-free output characteristics ( e and f in Fig. 5 ) showed improved μ e and hysteresis-free transistor characteristics showed enhanced electron transport for the DAAD-type P1 thin film compared to the DA-type PCDTPT.

[0168] Polymer μ max (cm 2 V -1 s -1 ) μ ave (cm 2 V -1 s -1 ) ON / OFF Ratio V T (V) p-Type n-Type p-Type n-Type p-Type n-Type p-Type n-Type P1 1.5 0.41 1.11(0.23) 0.28(0.05) 250 24 -42 60 P2 0.003 0.001 0.0013(0.0005) 0.0003(0.0002) 96 82 -33 66

[0169] Polymer Annealing temperature (°C) Stick μ (cm 2 IN -1 with -1 ) ON / OFF Ratio V T (V) P1 - 0.01 4.7×10 5 -20.3 80 0.13 7.1×10 4 -21.4 160 0.30 4.9×10 4 -21.4 240 0.33 1.0×10 5 -25.3 300 0.20 1.8×10 3 -38.4 P2 - 8.0×10 -4 3.0×10 6 31.2 80 1.0×10 -3 1.5×10 6 -8.5 160 1.0×10 -2 1.4×10 7 -20.8 240 8.0×10 -3 3.0×10 6 -30.4 300 6.0×10 -4 1.5×10 6 -2.6

[0170] P2 is 0.0013 ± 0.0005 cm 2 V -1 s -1 and 0.0003 ± 0.0002 cm 2 V -1 s -1 The average μ h and μ e It showed the value, where the highest μ h and μ e The values ​​are 0.003 cm each 2 V -1 s -1 and 0.001 cm 2 V -1 s -1 was ( d of Fig. 5 ). This value is more than 100 times smaller than the values ​​of P1, PCDTPT, and its DA-type counterpart (e.g., PCDTFBT). This low μ of P2. h and μ e The value is due to the low crystallinity of the P2 thin film ( Fig. 3 In addition, electron injection may be limited due to the higher CBE energy level of P2 ( d of Fig. 2 ). Despite these poor conditions for electron transport in P2 thin films, μ h Value (≒ 0.003 cm) 2 V -1 s -1 μ that can be reasonably compared with )e Value (≒ 0.001 cm) 2 V -1 s -1 ) demonstrates the applicability of the design strategy of the present invention to other polymer semiconductors, thereby demonstrating the importance of substituted atoms in DAAD-type polymer semiconductors.

[0172] To demonstrate the utility of bipolar P1 thin films, CMOS inverters were fabricated using annealed P1 thin films as p-channel and n-channel layers ( Insertion of Fig. 7a, Fig. 7b The inverter is a common gate input voltage (V). IN ), output voltage at the common drain (V OUT ), ground (GND), and supply voltage (V DD It consisted of 4 independent electrodes for each. V DD and V OUT and correspond to the pull-up (p-type transistor) parts, respectively, and GND and V OUT This corresponds to the pull-down (n-type transistor) part. In particular, an inverter was fabricated using a single layer of P1 without complex patterning. Fig. 7b shows the transfer characteristics and gain of a high-performance bipolar inverter. The above device is V OUT This V IN V, which increases according to but is driven by the operation of the pull-down transistor in the saturation region IN V near this GND DD It represented the general transfer characteristics of a bipolar inverter in that it does not reach. The maximum gain is V DD = It was about 110 at 100 V.

[0173] c of Fig. 7 is 60 V, 80 V, and 100 V DD Shows the transfer characteristics for the value. V DD Although small hysteresis (4 V or less) was observed at = 60 V, the inverter's transfer characteristics are V DDAs V decreases, the switching voltage (switching voltage; V SW ) is a typical characteristic of a bipolar inverter where it gradually decreases. In addition, the inverter V DD Regardless of, it exhibited sharp switching with a rail-to-rail output swing. The gain values ​​were V of 60 V and 80 V, respectively. DD The values ​​were determined to be 41 and 67 ( d of Fig. 7 The highest gain of 110 obtained from P1 is the first result for a CDT-based polymer semiconductor. Furthermore, this is one of the highest values ​​previously reported for an organic inverter based on a bipolar polymer semiconductor. These results demonstrate the advantages of the bipolar P1 semiconductor in organic logic circuits.

[0174] In addition, the thickness of the PMMA (dielectric) was reduced to 360 nm, and the width ratio of the p-type and n-type transistors among the inverter components was optimized (1:4) to fabricate an additional CMOS inverter, after which the gain value was measured. a of Fig. 8 ). Lower V DD A higher gain value (approximately 160 or higher) was obtained at (40 V). As a result, it was confirmed that excellent performance can be achieved using less power through device structure optimization.

[0176] 3. Conclusion

[0177] By simply rearranging the D and A moiety to form a DAAD configuration, the bipolar charge transport of the polymer semiconductor thin film was enhanced. Compared to conventional DA-type polymer semiconductors based on a CDT-PT configuration, the DAAD-type P1 containing a CDT-PT-PT-CDT framework in the repeating unit of the present invention exhibited electron and hole mobilities more than twice as high and hysteresis-free transistor characteristics. As a result, a CMOS inverter fabricated using a single-component bipolar P1 as a charge transport layer showed a high gain greater than 160. This is one of the highest values ​​reported for organic inverters developed with CDT-based polymer semiconductors. Since the strategy of the present invention is simple and can be applied to numerous previously reported DA-type polymer semiconductors, the results of the present invention provide simple, effective, and general guidelines for the design of high-performance bipolar polymer semiconductors and related organic electronic devices.

[0179] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0180] The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included within the scope of the present invention.

Claims

Claim 1 A bipolar polymer semiconductor thin film for a transistor comprising a bipolar polymer semiconductor represented by the following chemical formula 4, wherein the bipolar polymer semiconductor comprises a donor-acceptor-acceptor-donor moiety: [Chemical Formula 4] ,in the above chemical formula 4, R 1 and R 2 C, each independently, is linear or branched 1-30 It is an alkyl group, and n is an integer from 3 to 200. Claim 2 delete Claim 3 A bipolar polymer semiconductor thin film for a transistor according to claim 1, wherein the bipolar polymer semiconductor is represented by the following chemical formula 6: [Chemical Formula 6] , in the above chemical formula 6, n is an integer from 3 to 200. Claim 4 A bipolar polymer semiconductor thin film for a transistor according to claim 1, wherein the bipolar polymer semiconductor thin film for a transistor has a deeper conduction band edge energy level compared to a thin film containing a polymer containing a donor-acceptor moiety. Claim 5 A bipolar polymer semiconductor thin film for a transistor according to claim 1, wherein the conduction band edge energy level value of the bipolar polymer semiconductor thin film for a transistor is 2 eV to 5.5 eV. Claim 6 A bipolar polymer semiconductor thin film for a transistor according to claim 1, wherein the conduction band edge energy level difference value of the thin film comprising the polymer including the bipolar polymer semiconductor thin film for the transistor and the donor-acceptor moiety is 0.1 eV to 2 eV. Claim 7 A transistor comprising a semiconductor layer including a bipolar polymer semiconductor thin film for a transistor according to claim 1, wherein the semiconductor layer operates as an n-type and p-type semiconductor. Claim 8 In claim 7, the electron mobility of the transistor is 0.0001 cm 2 V -1 s -1 up to 0.5 cm 2 V -1 s -1 A transistor. Claim 9 In claim 7, the transistor is a transistor having hysteresis-free characteristics. Claim 10 In claim 7, the transistor is a transistor used in an inverter or a DC-AC converter. Claim 11 Reacting a donor precursor and an acceptor precursor under a Pd catalyst to obtain a donor-acceptor intermediate compound; reacting the donor-acceptor intermediate compound with hexa-n-butylditin under a Pd catalyst to obtain a donor-acceptor-acceptor-donor intermediate compound; reacting the donor-acceptor-acceptor-donor intermediate compound with N-bromosuccinimide to obtain a dibrominated donor-acceptor-acceptor-donor moiety; A method for manufacturing a bipolar polymer semiconductor comprising: [Formula 4], wherein the bipolar polymer semiconductor is represented by the following Chemical Formula 4, and the bipolar polymer semiconductor comprises a donor-acceptor-acceptor-donor moiety. ,in the above chemical formula 4, R 1 and R 2 C, each independently, is linear or branched 1-30 It is an alkyl group, and n is an integer from 3 to 200. Claim 12 A method for manufacturing a bipolar polymer semiconductor according to claim 11, wherein the manufacturing method is performed in the presence of a solvent. Claim 13 A method for manufacturing a bipolar polymer semiconductor according to claim 11, wherein obtaining the donor-acceptor-acceptor-donor intermediate compound is performed for 1 to 12 days at a temperature range of 100°C to 120°C.

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