WO2018068721A1

WO2018068721A1 - Randomly polymerized conjugated polymers containing random distribution of different side chains

Info

Publication number: WO2018068721A1
Application number: PCT/CN2017/105660
Authority: WO
Inventors: He Yan; Huatong YAO
Original assignee: The Hong Kong University Of Science And Technology
Priority date: 2016-10-11
Filing date: 2017-10-11
Publication date: 2018-04-19
Also published as: CN109890867B; CN109890867A

Abstract

A conjugated polymer comprises five or more repeating units of the following formula wherein x, y, n, Ar₁, Ar₂', and Ar₂" aredefined herein. Furthermore, an organic electronic (OE) device comprises the conjugated polymercomprising five or more repeating units of the following formula wherein x, y, n, Ar₁, Ar₂', and Ar₂" aredefined herein. Further, the OE device may comprise an organic solar cell (OSC).

Description

[Title established by the ISA under Rule 37.2] RANDOMLY POLYMERIZED CONJUGATED POLYMERS CONTAINING RANDOM DISTRIBUTION OF DIFFERENT SIDE CHAINS

CROSS REFERENCE

The present application claims priority to provisional United States Patent Application No. 62/496,208, filed October 11, 2016, which was filed by the inventors hereof and is incorporated herein in its entirety.

TECHNICAL FIELD

The present subject matter generally relates to donor-acceptor conjugated polymers, methods for their preparation, and intermediates used therein. The present subject matter relates to the use of formulations containing such polymers as semiconductors in organic electronic (OE) devices, especially in organic photovoltaics (OPV) and organic field-effect transistor (OFET) devices, and to corresponding OE and OPV devices made from such formulations.

BACKGROUND

In recent years there has been growing interest in the use of organic semiconductors, including conjugated polymers, for various electronic applications. One area of importance is in the field of organic photovoltaics. Organic semiconductors (OSCs) have found use in the field of organic photovoltaics, as OSCs allow devices to be manufactured by solution-processing techniques, such as spin casting and printing. Compared to the evaporative techniques used to make inorganic thin film devices, solution processing can be carried out on a larger scale and is typically cheaper than evaporative techniques.

Many reports have shown that the size of side chains on conjugated polymers has a large impact on the performance of organic solar cells. When side chains are too short, the polymer will be insoluble, which makes organic solar cells hard to fabricate. When side chains are too long, the mobility of the polymer will dramatically decrease, which leads to inferior performance. Moreover, the size of side chains affects the morphology of organic solar cells, which is the key factor in achieving efficient organic solar cells. Therefore, a large number of researchers have spent a great amount of time and effort focused on tuning the size of polymer side chains to optimize the performance of OPVs. Because researchers usually must carry out the synthesis from scratch in order to tune the synthesis, this is a time-consuming process.

Furthermore, sometimes the synthesis of some side chains cannot be prepared directly from commercially available materials. For example, the power conversion efficiency (PCE) of 11.7％ (a record PCE to-date) was achieved based on the PffBT4T-C9C13: PC71BM single-junction organic solar cells. However, theside chains used in the 11.7％polymer were not the commonlyused 2-octyldodecyl or 2-decyltetradecyl alkyl chains, which are two alkyl chains commercially available at a very low price. Instead, the alkyl chain used in the 11.7％polymer was a specially tailored side chain that was synthesized in-house and had a long synthesis route. Although this side chain produced optimum performance, the cost of synthesizing this side chain is too high. Therefore, this example demonstrates the importance of having optimum side chains, but also highlights that a solution is needed to easily optimize side chains at a low cost. For organic solar cells to be commercially successful, it is necessary to make high performance organic solar cells having a low cost.

SUMMARY

In an embodiment, the present subject matter is directed to a conjugated polymer comprising five or more repeating units of the following formula

wherein

x and y are real numbers representing molar fractions, wherein 0 < x < 1, 0 < y < 1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

each Ar₁ is independently selected from the group consisting of unsubstituted or substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein each Ar₁ may contain one to five of said arylene or heteroarylene each of which may be fused or linked； and

each Ar₂’and Ar₂”is independently selected from the group consisting of substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein Ar₂’and Ar₂”may contain one to five of said arylene or heteroarylene each of which may be fused or linked； wherein Ar₂’and Ar₂”have substitution groups including but not limited to alkyl side chains； and wherein Ar₂”has a nearly identical chemical structure to Ar₂’except substitution groups on Ar₂”differ from those on Ar₂’.

In an embodiment, the present subject matter is directed to an organic electronic (OE) device comprising the conjugated polymer of the present subject matter. In an embodiment, the OE device is an organic solar cell (OSC) .

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the J-V curves of V7: PC₇₁BM-based solar cells processed from TMB or TMB-DIO.

FIG. 2 shows the UV-Vis absorption spectra of V7 at elevated temperatures in a 0.01 mg mL^-1 CB solution. The insets indicate temperatures (units: ℃) .

FIG. 3 shows the UV-Vis absorption spectra of V10 at elevated temperatures in a 0.01 mg mL^-1 CB solution. The insets indicate temperatures (units: ℃) .

FIG. 4 shows the UV-Vis absorption spectra of V15 at elevated temperatures in a 0.01 mg mL^-1 CB solution. The insets indicate temperatures (units: ℃) .

DETAILED DESCRIPTION

Definitions

Throughout the application, where compositions are described as having, including, or comprising specific components, or where processes are described as having, including, orcomprising specific process steps, it is contemplated that compositions of the presentteachings can also consist essentially of, or consist of, the recited components, and that theprocesses of the present teachings can also consist essentially of, or consist of, the recited processsteps.

In the application, where an element or component is said to be included in and/orselected from a list of recited elements or components, it should be understood that theelement or component can be any one of the recited elements or components, or the elementor component can be selected from a group consisting of two or more of the recited elementsor components. Further, it should be understood that elements and/or features of acomposition, an apparatus, or a method described herein can be combined in a variety ofways without departing from the spirit and scope of the present teachings, whether explicit orimplicit herein

The use of the terms “include” , “includes” , “including” , “have” , “has” , or “having” should be generally understood as open-ended and non-limiting unless specifically statedotherwise.

The use of the singular herein includes the plural (and vice versa) unless specificallystated otherwise. In addition, where the use of the term “about” is before a quantitativevalue, the present teachings also include the specific quantitative value itself, unlessspecifically stated otherwise. As used herein, the term “about” refers to a ±10％variationfrom the nominal value unless otherwise indicated or inferred.

It should be understood that the order of steps or order for performing certainactions is immaterial so long as the present teachings remain operable. Moreover, two ormore steps or actions may be conducted simultaneously.

As used herein, a “p-type semiconductor material” or a “donor” material refers to asemiconductor material having holes as themajority current or charge carriers, for example, an organic semiconductor material. In some embodiments, when a p-type semiconductormaterial is deposited on a substrate, it can provide a hole mobility in excess of about 10^-5cm²/Vs. In the case of field-effect devices, a p-type semiconductor also can exhibit a currenton/off ratio of greater than about 10.

As used herein, an “n-type semiconductor material” or an “acceptor” material refersto a semiconductor material havingelectrons as the majority current or charge carriers, for example, an organic semiconductor material. In some embodiments, when an n-typesemiconductor material is deposited on a substrate, it can provide an electron mobility inexcess of about 10^- ⁵cm²/Vs. In the case of field-effect devices, an n-type semiconductor alsocan exhibit a current on/off ratio of greater than about 10.

As used herein, “mobility” refers to a measure of the velocity with which chargecarriers, for example, holes (or units of positive charge) in the case of a p-type semiconductormaterial and electrons (or units of negative charge) in the case of an n-type semiconductormaterial, move through the material under the influence of an electric field. This parameter, which depends on the device architecture, can be measured using a field-effect device orspace-charge limited current measurements.

As used herein, a compound can be considered “ambient stable” or “stable atambient conditions” when a transistor incorporating the compound as its semiconductingmaterial exhibits a carrier mobility that is maintained at about its initial measurement whenthe compound is exposed to ambient conditions, for example, air, ambient temperature, andhumidity, over a period of time. For example, a compound can be described as ambientstable if a transistor incorporating the compound shows a carrier mobility that does not varymore than 20％or more than 10％from its initial value after exposure to ambient conditions, including, air, humidity, and temperature, over a 3 day, 5 day, or 10 day period.

As used herein, fill factor (FF) is the ratio (given as a percentage) of the actualmaximum obtainable power, (Pm or Vmp *Jmp) , to the theoretical (not actually obtainable) power, (Jsc *Voc) . Accordingly, FF can be determined using the equation:

FF ＝ (Vmp *Jmp) / (Jsc *Voc)

where Jmpand Vmprepresent the current density and voltage at the maximum power point (Pm) , respectively, this point being obtained by varying the resistance in the circuit until J *Vis at its greatest value； and Jscand Vocrepresent the short circuit current and the open circuitvoltage, respectively. Fill factor is a key parameter in evaluating the performance of solarcells. Commercial solar cells typically have a fill factor of about 0.60％or greater.

As used herein, the open-circuit voltage (Voc) is the difference in the electricalpotentials between the anode and the cathode of a device when there is no external loadconnected.

As used herein, the power conversion efficiency (PCE) of a solar cell is thepercentage of power converted from absorbed light to electrical energy. The PCE of a solarcell can be calculated by dividing the maximum power point (Pm) by the input lightirradiance (E, in W/m²) under standard test conditions (STC) and the surface area of the solarcell (Ac in m²) . STC typically refers to a temperature of 25℃ and an irradiance of 1000W/m² with an air mass 1.5 (AM 1.5) spectrum.

As used herein, a component (such as a thin film layer) can be considered “photoactive” if it contains one or more compounds that can absorb photons to produceexcitons for the generation of a photocurrent.

As used herein, “solution-processable” refers to compounds (e.g., polymers) , materials, or compositions that can be used in various solution-phase processes includingspin-coating, printing (e.g., inkjet printing, gravure printing, offset printing and the like) , spray coating, electrospray coating, drop casting, dip coating, blade coating, and the like.

As used herein, a “semicrystalline polymer” refers to a polymer that has an inherenttendency to crystallize at least partially either when cooled from a melted state or depositedfrom solution, when subjected to kinetically favorable conditions such as slow cooling, orlow solvent evaporation rate and so forth. The crystallization or lack thereof can be readilyidentified by using several analytical methods, for example, differential scanning calorimetry (DSC) and/or X-ray diffraction (XRD) .

As used herein, “annealing” refers to a post-deposition heat treatment to thesemicrystalline polymer film in ambient or under reduced/increased pressure for a timeduration of more than 100 seconds, and “annealing temperature” refers to the maximumtemperature that the polymer film is exposed to for at least 60 seconds during this process ofannealing. Without wishing to be bound by any particular theory, it is believed thatannealing can result in an increase of crystallinity in the polymer film, where possible, thereby increasing field effect mobility. The increase in crystallinity can be monitored byseveral methods, for example, by comparing the DSC orXRD measurements of the as-deposited and the annealed films.

As used herein, a “polymeric compound” (or “polymer” ) refers to a moleculeincluding a plurality of one or more repeating units connected by covalent chemical bonds. Apolymeric compound can be represented by General Formula I:

*- (- (Ma) _x— (Mb) _y—) _z*

General Formula I

wherein each Ma and Mb is a repeating unit or monomer. The polymeric compound can have only onetype of repeating unit as well as two or more types of different repeating units. When apolymeric compound has only one type of repeating unit, it can be referred to as ahomopolymer.

When a polymeric compound has two or more types of different repeatingunits, the term “copolymer” or “copolymeric compound” can be used instead. For example, a copolymeric compound can include repeating unitswhere Ma and Mb represent two different repeating units. Unless specified otherwise, theassembly of the repeating units in the copolymer can be head-to-tail, head-to-head, or tail-to-tail. In addition, unless specified otherwise, the copolymer can be a random copolymer, analternating copolymer, or a block copolymer. For example, General Formula I can be used to represent a copolymer of Ma and Mb having x mole fraction of Ma and y molefraction of Mb in the copolymer, where the manner in which comonomers Ma and Mb is repeated can be alternating, random, regiorandom, regioregular, or in blocks, with up to z comonomers present. In addition toits composition, a polymeric compound can be further characterized by its degree ofpolymerization (n) and molar mass (e.g., number average molecular weight (M) and/orweight average molecular weight (Mw) depending on the measuring technique (s) ) .

As used herein, “halo” or “halogen” refers to fluoro, chloro, bromo, and iodo.

As used herein, “alkyl” refers to a straight-chain or branched saturated hydrocarbon group. Examples of alkyl groups include methyl (Me) , ethyl (Et) , propyl (e.g., n-propyl andz'-propyl) , butyl (e.g., n-butyl, z'-butyl, sec-butyl, tert-butyl) , pentyl groups (e.g., n-pentyl, z'-pentyl, -pentyl) , hexyl groups, and the like. In various embodiments, an alkyl groupcan have 1 to 40 carbon atoms (i.e., C1-40 alkyl group) , for example, 1-30 carbon atoms (i.e., C1-30 alkyl group) . In some embodiments, an alkyl group can have 1 to 6 carbon atoms, andcan be referred to as a “lower alkyl group” . Examples of lower alkyl groups include methyl, ethyl, propyl (e.g., n-propyl and z'-propyl) , and butyl groups (e.g., n-butyl, z'-butyl, sec-butyl, tert-butyl) . In some embodiments, alkyl groups can be substituted as described herein. An alkyl group is generally not substituted with another alkyl group, an alkenyl group, or analkynyl group.

As used herein, “alkenyl” refers to a straight-chain or branched alkyl group havingone or more carbon-carbon double bonds. Examples of alkenyl groups include ethenyl, propenyl, butenyl, pentenyl, hexenyl, butadienyl, pentadienyl, hexadienyl groups, and thelike. The one or more carbon-carbon double bonds can be internal (such as in 2-butene) orterminal (such as in 1-butene) . In various embodiments, an alkenyl group can have 2 to 40carbon atoms (i.e., C2-40 alkenyl group) , for example, 2 to 20 carbon atoms (i.e., C2-20 alkenylgroup) . In some embodiments, alkenyl groups can be substituted as described herein. Analkenyl group is generally not substituted with another alkenyl group, an alkyl group, or analkynyl group.

As used herein, a “fused ring” or a “fused ring moiety” refers to a polycyclic ringsystem having at least two rings where at least one of the rings is aromatic and such aromaticring (carbocyclic or heterocyclic) has a bond in common with at least one other ring that canbe aromatic or non-aromatic, and carbocyclic or heterocyclic. These polycyclic ring systemscan be highly p-conjugated and optionally substituted as described herein.

As used herein, “heteroatom” refers to an atom of any element other than carbon orhydrogen and includes, for example, nitrogen, oxygen, silicon, sulfur, phosphorus, andselenium.

As used herein, “aryl” refers to an aromatic monocyclic hydrocarbon ring system ora polycyclic ring system in which two or more aromatic hydrocarbon rings are fused (i.e., having a bond in common with) together or at least one aromatic monocyclic hydrocarbonring is fused to one or more cycloalkyl and/or cycloheteroalkyl rings. An aryl group canhave 6 to 24 carbon atoms in its ring system (e.g., C6-24 aryl group) , which can includemultiple fused rings. In some embodiments, a polycyclic aryl group can have 8 to 24 carbonatoms. Any suitable ring position of the aryl group can be covalently linked to the definedchemical structure. Examples of aryl groups having only aromatic carbocyclic ring (s) include phenyl, 1-naphthyl (bicyclic) , 2-naphthyl (bicyclic) , anthracenyl (tricyclic) , phenanthrenyl (tricyclic) , pentacenyl (pentacyclic) , and like groups. Examples of polycyclicring systems in which at least one aromatic carbocyclic ring is fused to one or morecycloalkyl and/or cycloheteroalkyl rings include, among others, benzo derivatives ofcyclopentane (i.e., an indanyl group, which is a 5, 6-bicyclic cycloalkyl/aromatic ringsystem) , cyclohexane (i.e., a tetrahydronaphthyl group, which is a 6, 6-bicycliccycloalkyl/aromatic ring system) , imidazoline (i.e., a benzimidazolinyl group, which is a 5,6-bicyclic cycloheteroalkyl/aromatic ring system) , and pyran (i.e., a chromenyl group, which isa 6, 6-bicyclic cycloheteroalkyl/aromatic ring system) . Other examples of aryl groups includebenzodioxanyl, benzodioxolyl, chromanyl, indolinyl groups, and the like. In someembodiments, aryl groups can be substituted as described herein. In some embodiments, anaryl group can have one or more halogen substituents, and can be referred to as a “haloaryl” group. Perhaloaryl groups, i.e., aryl groups where all of the hydrogen atoms are replacedwith halogen atoms (e.g., -C6F5) , are included within the definition of “haloaryl” . In certainembodiments, an aryl group is substituted with another aryl group and can be referred to as abiaryl group. Each of the aryl groups in the biaryl group can be substituted as disclosedherein.

As used herein, “heteroaryl” refers to an aromatic monocyclic ring systemcontaining at least one ring heteroatom selected from oxygen (O) , nitrogen (N) , sulfur (S) , silicon (Si) , and selenium (Se) or a polycyclic ring system where at least one of the ringspresent in the ring system is aromatic and contains at least one ring heteroatom. Polycyclicheteroaryl groups include those having two or more heteroaryl rings fused together, as wellas those having at least one monocyclic heteroaryl ring fused to one or more aromaticcarbocyclic rings, non-aromatic carbocyclic rings, and/or non-aromatic cycloheteroalkylrings. A heteroaryl group, as a whole, can have, for example, 5 to 24 ring atoms and contain1-5 ring heteroatoms (i.e., 5-20 membered heteroaryl group) . The heteroaryl group can beattached to the defined chemical structure at any heteroatom or carbon atom that results in astable structure. Generally, heteroaryl rings do not contain O-O, S-S, or S-0 bonds. However, one or more N or S atoms in a heteroaryl group can be oxidized (e.g., pyridine Noxidethiophene S-oxide, thiopheneS, S-dioxide) . Examples of heteroaryl groups include, for example, the 5-or 6-membered monocyclic and 5-6 bicyclic ring systems shown below: where T is O, S, NH, N-alkyl, N-aryl, N- (arylalkyl) (e.g.， N-benzyl) , SiH2, SiH (alkyl) , Si (alkyl) 2, SiH (arylalkyl) , Si (arylalkyl) 2, or Si (alkyl) (arylalkyl) . Examples of such heteroarylrings include pyrrolyl, furyl, thienyl, pyridyl, pyrimidyl, pyridazinyl, pyrazinyl, triazolyl, tetrazolyl, pyrazolyl, imidazolyl, isothiazolyl, thiazolyl, thiadiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, indolyl, isoindolyl, benzofuryl, benzothienyl, quinolyl, 2-methylquinolyl, isoquinolyl, quinoxalyl, quinazolyl, benzotriazolyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzisoxazolyl, benzoxadiazolyl, benzoxazolyl, cinnolinyl, lH-indazolyl, 2H-indazolyl, indolizinyl, isobenzofuyl, naphthyridinyl, phthalazinyl, pteridinyl, purinyl, oxazolopyridinyl, thiazolopyridinyl, imidazopyridinyl, furopyridinyl, thienopyridinyl, pyridopyrimidinyl, pyridopyrazinyl, pyridopyridazinyl, thienothiazolyl, thienoxazolyl, thienoimidazolyl groups, and the like. Further examples of heteroaryl groups include 4, 5, 6, 7-tetrahydroindolyl, tetrahydroquinolinyl, benzothienopyridinyl, benzofuropyridinyl groups, and the like. In some embodiments, heteroaryl groups can be substituted as described herein.

Furthermore, it should be understood that the drawings described herein are for illustration purposes only. The drawings are not necessarily to scale, with emphasis generally being placed upon illustrating the principles of the present teachings. The drawings are not intended to limit the scope of the present teachings in any way.

Randomly Polymerized D-APolymers

In the present subject matter, a new approach is developed that achieves the same effect of optimum side chains without time-consuming and costly synthesis. The new approach allows for random polymerization of two units whileusing existing commercially available side chains, such as 2-octyldodecyl and 2-decyltetradecyl alkyl chains. For example, one unit contains 2-octyldodecyl alkyl chains and the other unit contains 2-decyltetradecyl alkyl chains. A randomly polymerized polymer can be obtained by adjusting the ratio of the two copolymer units with two different side chains. The properties of the polymer may then be fine-tuned in order to achieve the same performance as PffBT4T-C9C13. In this approach, it is not necessary to synthesize new side chains that are expensive and time-consuming. Instead, existing commercially available side chains may be used to reach the same optimum device performance.

It was surprisingly found that the randomly polymerized polymers containing a random distribution of alkyl side chains with different sizes can achieve excellent performance, despite the random nature of the polymer, as shown below.

By intuition, one may expect that random polymerization might hurt the crystallinity, charge transport ability and thus the PSC performance of donor polymers. Particularly for these temperature-dependent-aggregation (TDA) polymers, their main advantage is the high crystallinity and strong inter-digitation between the alkyl chains. If the alkyl chains are randomly distributed, the alkyl chain inter-digitation and polymer crystallinity may be negatively affected. Therefore, it is not obvious that a random polymer can achieve performance as good as PffBT4T-C9C13. Surprisingly, the present study showed that the donor polymers randomly polymerized using two monomers with even-numbered alkyl chains can work effectively, and produce high-efficiency PSCs. Most importantly, it was found that both structural and electronic properties of the random polymer can be finely tuned between the regular polymers that comprise only C8C12 or C10C14 alkyl chains. Furthermore, upon blending with fullerene acceptors, these randomly polymerized donor polymers with even-numbered alkyl chains can achieve a high PCE up to 11.1％, which is comparable to that obtained using odd-numbered, C9C13 alkyl chains.

Therefore, in an embodiment ofthe present subject matter, a new method of making random polymers has been developed by using two building blocks with same structure, except for the size of side chains. Obtaining optimum size of side chains is a time-consuming process and sometimes particular side chains are not commercially available. By using the present approach, the aforementioned hurdle can be easily overcome. In particular, by using a different ratio of two building blocks with the same structure (except for the size of side chains) to synthesize random polymers, it is facile to tune the size of the side chains on polymers. This enables the enhancement of the power convertion efficiency up to 11.1％, or higher, and dramatically simplifies the tuning process, which is beneficial for both industrial and academicpurposes.

wherein

n is an integer that is 5 or greater；

In an embodiment, the conjugated polymer of the present subject matter comprises five or more repeating units of the following formula:

wherein

x and y are real numbers representing mole fractions, wherein 0 < x < 1, 0 < y < 1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

each Ar₁ and Ar₂is independently selected from the group consisting of unsubstituted or substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein each Ar₁ and Ar₂ may contain one to five of said arylene or heteroarylene each of which may be fused or linked； and

each R₁andR₂ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optically replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； wherein R₁is not the same as R₂.

wherein

n is an integer that is 5 or greater；

each Ar₁, Ar₂, and Ar₃ is independently selected from the group consisting of unsubstituted or substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein Ar₁, Ar₂, and Ar₃ may contain one to five of said arylene or heteroarylene each of which may be fused or linked； and

each R₁ and R₂ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optically replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； wherein R₁is not the same as R₂.

In an embodiment, the conjugated polymer of the present subject matter comprises five or more repeating unit of the following formula:

wherein

n is an integer that is 5 or greater；

each Z₁ is S or Se；

each Z₂ is N or C-H；

each Ar₁ and Ar₂is independently selected from the group consisting of unsubstituted or substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein Ar₁and Ar₂ may contain one to five of said arylene or heteroarylene each of which may be fused or linked； and

wherein

n is an integer that is 5 or greater；

wherein

n is an integer that is 5 or greater；

eachR₁ and R₂ is independently selected from the group consisting of branched alkyl groups with 2-40 C atoms； wherein R₁is not the same as R₂.

wherein

n is an integer that is 5 or greater；

eachR₁ and R₂ is independently selected from second branched alkyl groups with 2-40 C atoms； wherein R₁is not the same as R₂； and

each Ar₁ and Ar₂is independently selected from the group consisting of:

wherein

each Z₁, Z₂, Z₃, Z₄, Z₅, and Z₆ is S, O, or Se；

each X, X₁, X₂, X₃, X₄, X₅, X₆, X₇, and X₈ is H, F, or Cl； and

each R, R₃, and R₄ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optically replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group.

In an embodiment, the average molecular weight of the conjugated polymer is in a range from 10,000 to 200,000 gram/mole. In an embodiment, a solution of the conjugated polymer exhibits a peak optical absorption spectrum red shift of at least 50 nm when the conjugated polymer solution is cooled from 140℃ to room temperature.

In an embodiment, the conjugated polymer of the present subject matter comprises one or more repeating units selected from the following formulas:

wherein

x and y are real numbers representing mole fractions, wherein 0 < x < 1, 0 < y < 1, and the sum of x and y is about 1；

n is an integer that is 5 or greater；

each Z₁, Z₂, Z₃, Z₄, Z₅, Z₆, Z₇, and Z₈ is S, O, or Se；

eachX, X₁, X₂, X₃, and X₄ is H, F, or Cl； and

eachR₁, R_2, and R₃ is a second position branched side chain； wherein R₁is not the same as R₂.

wherein

n is an integer that is 5 or greater；

each Z₁, Z₂, Z₃, Z₄, and Z₅ is S, O, or Se；

each Z₆ is CH₂, S, or O；

each Z₇ is H, F, or Cl； and

each R₁, R₂, and R₃ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optically replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； wherein R₂is not the same as R₃.

wherein

n is an integer that is 5 or greater；

each Z₆ is CH₂, S, or O；

each Z₇ is H, F, or Cl； and

eachR₁, R₂, and R₃ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms； wherein R₂is not the same as R₃.

In an embodiment, the conjugated polymer of the present subject matter comprises a formula selected from the group consisting of:

wherein

n is an integer that is 5 or greater； and

eachR is selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms.

In an embodiment, the conjugated polymer of the present subject matter exhibits temperature-dependent aggregation properties, characterized in that a solution of the conjugated polymer exhibits a peak optical absorption spectrum red shift of at least 50 nm when the conjugated polymer solution is cooled from 140℃ to room temperature.

wherein

n is an integer that is 5 or greater；

each Z₁ and Z₂ is S, O, or Se；

each Z₃ is CH₂, S, or O；

each Z₄ and Z₅ is H, F, or Cl； and

wherein

n is an integer that is 5 or greater；

each Z₃ is CH₂, S, or O；

each Z₄ and Z₅ is H, F, or Cl； and

eachR₁, R₂ and R₃ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms； wherein R₂is not the same as R₃.

wherein x and y are real numbers representing mole fractions, wherein 0 < x < 1, 0 < y < 1, and the sum of x and y is equal or less than 1.

wherein

x₁ is 0.25 or 0.5 or 0.75；

x₂ and x₃ are 0.5； and

n is an integer that is 5 or greater.

Formulations of the present teachings can exhibit semiconductor behavior such asoptimized light absorption/charge separation in a photovoltaic device； chargetransport/recombination/light emission in a light-emitting device； and/or high carrier mobilityand/or good current modulation characteristics in a field-effect device. In addition, thepresent formulations can possess certain processing advantages such as solution-processabilityand/or good stability (e.g., air stability) in ambient conditions. The formulations of the presentteachings can be used to prepare either p-type (donor or hole-transporting) , n-type (acceptoror electron-transporting) , or ambipolar semiconductor materials, which in turn can be used tofabricate various organic or hybrid optoelectronic articles, structures and devices, includingorganic photovoltaic devices and organic light-emitting transistors.

In an embodiment, an organic electronic (OE) device comprises a coating or printing ink containing the present formulation. Another embodiment is further characterized in that the OE device is an organic field effect transistor (OFET) device. Another embodiment is further characterized in that the OE device is an organic photovoltaic (OPV) device.

In an embodiment, the present subject matter is directed to a donor-acceptor conjugated polymer comprising one or more repeating units having a formula of:

wherein

x and y are real numbers representing mole fractions, wherein 0 < x < 1, 0 < y < 1, and a sum of x and y is about 1；

each R₁ and R₂ is independently selected from the group consisting of straight-chain, branched, and cyclic alkyl with 20-40 C atoms, wherein one or more non-adjacent C atoms are optionally replaced by –O–, –S–, –C (O) –, –C (O–) –O–, –O–C (O) –, –O–C (O) –O–, –CR⁰＝CR⁰⁰–, or –C≡C–, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； wherein each R₁ and R₂ are not all identical；

each Ar₁ and Ar₂ is independently selected from the group consisting of an unsubstituted or substituted monocyclic, bicyclic, or polycyclic arylene and a monocyclic, bicyclic, and polycyclic heteroarylene； wherein each Ar₁ and Ar₂ may contain one to five of the unsubstituted or substituted monocyclic, bicyclic, or polycyclic arylene and the monocyclic, bicyclic, and polycyclic heteroarylene, each of which may be fused or linked； and

wherein the conjugated polymer is not poly (3-hexylthiophene-2, 5-diyl) (P3HT) .

In an embodiment, Ar₁ is selected from the group consisting of:

wherein

each X¹ is independently selected from the group consisting of F, H, and OR₃； and

each R₃ and R is independently selected from the group consisting of straight-chain, branched, and cyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optionally replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group.

In an embodiment, Ar₂ is selected from the group consisting of:

wherein

each X¹ is independently selected from the group consisting of F, H, and OR₃, and

each R₃ is independently selected from the group consisting of straight-chain, branched, and cyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optionally replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, aryxycarbonyl, heteroarylcarbonyloxy, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group.

In an embodiment, the donor-acceptor conjugated polymer has an average molecular weight in a range of 10,000 to 100,000 gram/mole. In an embodiment, a solution of the donor- acceptor conjugated polymer exhibits a peak optical absorption spectrum red shift of at least 50 nm when the solution is cooled from 140℃ to room temperature. In an embodiment, the donor-acceptor conjugated polymer has an optical bandgap of 2.2 eV or lower.

In an embodiment, the donor-acceptor conjugated polymer has a structure of:

wherein

each R₁ and R₂ is independently selected from the group consisting of straight-chain, branched, and cyclic alkyl with 20-40 C atoms, wherein one or more non-adjacent C atoms are optionally replaced by –O–, –S–, –C (O) –, –C (O–) –O–, –O–C (O) –, –O–C (O) –O–, –CR⁰＝CR⁰⁰–, or –C≡C–, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； and wherein each R₁ and R₂ are not all identical.

In an embodiment, the donor-acceptor conjugated polymer has a structure of:

wherein

x and y are real numbers representing mole fractions, wherein 0 < x < 1, 0 < y < 1, and a sum of x and y is about 1.

In an embodiment, x＝0.25, y＝0.75, and the donor-acceptor conjugated polymer has a power conversion efficiency (PCE) of up to 10.14％. In an embodiment, x＝0.5, y＝0.5, and the donor-acceptor conjugated polymer has a power conversion efficiency (PCE) of up to 11.22％. In an embodiment, x＝0.75, y＝0.25, and the donor-acceptor conjugated polymer has a power conversion efficiency (PCE) of up to 10.03％. In an embodiment, the unit comprising x mole fraction and the unit comprising y mole fraction are repeated in a random manner.

In an embodiment, the donor-acceptor conjugated polymer is selected from the group consisting of:

For instance, in anon-limiting embodiment, the V7 polymer was synthesized, achieving 11.22％power conversion efficiency. In an embodiment, theV10 polymer was synthesized, achieving 10.14％power conversion efficiency. In an embodiment, the V15 polymer was synthesized, achieving 10.03％power conversion efficiency.

Formulations Comprising the D-APolymers

In an embodiment, the present subject matter is directed to a formulation comprising:

an organic solvent,

a fullerene or non-fullerene acceptor, and

a donor-acceptor conjugated polymer comprising one or more repeating units having a formula of:

wherein x and y are real numbers representing mole fractions, wherein 0 < x < 1, 0 < y <1, and a sum of x and y is about 1；

wherein each R₁ and R₂ is independently selected from the group consisting of straight-chain, branched, and cyclic alkyl with 20-40 C atoms, wherein one or more non-adjacent C atoms are optionally replaced by –O–, –S–, –C (O) –, –C (O–) –O–, –O–C (O) –, –O–C (O) –O–, –CR⁰＝CR⁰⁰–, or –C≡C–, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； wherein each R₁ and R₂ are not all identical；

whereinAr₁ is selected from the group consisting of:

wherein Ar₂ is selected from the group consisting of:

wherein each X¹ is independently selected from the group consisting of F, H, and OR₃；

wherein each R₃ and R is independently selected from the group consisting of straight-chain, branched, and cyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optionally replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group.

Any other polymer described herein can likewise be used in formulations with the organic solvent and the fullerene or non-fullerene acceptor.

In an embodiment, the fullerene is selected from the group consisting of:

wherein

each n ＝ 1, 2, 4, 5, or 6；

eachAr is independently selected from the group consisting of monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein each Ar may contain one to five of said arylene or heteroarylene each of which may be fused or linked；

each R^x is independently selected from the group consisting of Ar, straight-chain, branched, and cyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optionally replaced by –O–, –S–, –C (O) –, –C (O–) –O–, –O–C (O) –, –O–C (O) –O–, –CR⁰＝CR⁰⁰–, or –C≡C–, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group；

each R is independently selected from the group consisting of straight-chain, branched, and cyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optionally replaced by –O–, –S–, –C (O) –, –C (O–) –O–, –O–C (O) –, –O–C (O) –O–, –CR⁰＝CR⁰⁰–, or –C≡C–, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group；

each R¹ is independently selected from the group consisting of straight-chain, branched, and cyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optionally replaced by –O–, –S–, –C (O) –, –C (O–) –O–, –O–C (O) –, –O–C (O) –O–, –CR⁰＝CR⁰⁰–, or –C≡C–, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein the number of carbon that R¹ contains is larger than 1, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group；

each Ar¹ is independently selected from the group consisting of monocyclic, bicyclic and polycyclic heteroaryl groups, wherein each Ar¹ may contain one to five of said heteroaryl groups each of which may be fused or linked；

each Ar² is independently selected from aryl groups containing more than 6 atoms excluding H； and

wherein a fullerene ball represents a fullerene selected from the group consisting of C60, C70, C84, and other fullerenes.

In an embodiment, the fullerene is substituted by one or more functional groups selected from the group consisting of:

wherein

each n ＝ 1-6；

each Ar is independently selected from the group consisting of monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, or may contain one to five such groups, either fused or linked；

wherein the fullerene ball represents a fullerene selected from the group consisting of C60, C70, C84, and other fullerenes.

In some embodiments, the formulation is further characterized in that the fullerene is selected from the group consisting of:

In an embodiment, the formulation is further characterized in that the fullerene is selected from the group consisting of:

wherein

each n ＝ 1-6；

each m ＝ 1, 2, 4, 5, or 6；

each q ＝ 1-6；

each R¹ and R² is independently selected from the group consisting of C1-4 straight and branched chain alkyl groups； and

wherein the fullerene ball represents a fullerene from the group consisting of C60, C70, C84, and other fullerenes.

In an embodiment, the non-fullerene acceptor is selected from the group consisting of:

wherein each R is independently selected from the group consisting of Ar, straight-chain, branched, and cyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optionally replaced by –O–, –S–, –C (O) –, –C (O–) –O–, –O–C (O) –, –O–C (O) –O–, –CR⁰＝CR⁰⁰–, or –C≡C–, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group.

In an embodiment, the present subject matter is directed to an organic electronic (OE) device comprising a coating or printing ink comprising a formulation according to the present subject matter. In an embodiment, the OE device is an organic field effect transistor (OFET) device or an organic solar cell (OSC) device. In an embodiment, the OE device has a power conversion efficiency of up to 11.22％.

EXAMPLES

Example 1: Synthetic Route to V7, V10, and V15

The synthetic route to V7, V10, and V15 is shown below in Scheme 1.

Scheme 1:

Step 1: Preparation of S3 (5, 6-Difluoro-4, 7-bis (4- (2-octyldodecyl) -2-thienyl) -2, 1, 3-benzothiadiazole)

A solution of 3- (2-octyldodecyl) thiophene (S2, 5.00 g, 13.7 mmol) in 50 mL THF wascooled to -78℃ under N₂. A solution of lithium diisopropylamide (2 M, 8.3 mL, 16.6mmol) was added dropwise and the mixture was stirred at -78℃ for 1 hour and then returned to 0℃ and stirred for an additional 1 hour. The mixture was then cooled to -78℃, and tri-n-butyltin chloride (6.50 g, 20 mmol) was added in one portion. The reaction mixture was returned to room temperature and stirred overnight. A solution of KF in water was added, and the organic phase was washed with water three times, then dried with Na₂SO₄. The solvent was evaporated to get the crude product as a yellow oil, which was directly used without further purification.

A mixture of 2- (tri-n-butylstannyl) -4- (2-octyldodecyl) thiophene (1.96 g, ～3 mmol) , 4, 7-dibromo-5, 6-difluoro-2, 1, 3-benzothiadiazole (S1, 330mg, 1 mmol) , Pd₂ (dba) ₃ (11mg, 0.02 mmol) , and P (o-tol) ₃ (24 mg, 0.08 mmol) in 10 mL THF was refluxed overnight under N₂. The reaction mixture was then cooled to room temperature, and the solvent was evaporated. The residue was purified by flash column chromatography (eluent: n-hexane) to get the product as a yellow solid (650 mg, 73％) .

1H NMR (400 MHz, CDCl3) δ 8.11 (s, 2H) , 7.19 (s, 2H) , 2.66 (d, J ＝ 6.7 Hz, 4H) , 1.77 –1.62 (m, 2H) , 1.42 –1.14 (m, 64H) , 0.97 –0.84 (m, 12H) . 19F NMR (376 MHz, CDCl3) δ -128.27 (s, 2F) .

13C NMR (100 MHz, CDCl3) δ 149.75 (dd, J ＝ 257.9, 20.2 Hz) , 148.94 (t, J ＝ 4.1Hz) , 142.36, 132.81 (t, J ＝ 3.8 Hz) , 130.99, 124.83, 111.69 (dd, J ＝ 9.2, 4.3 Hz) , 38.97, 34.88, 33.34, 31.93, 30.05, 29.71, 29.67, 29.38, 26.66, 22.70, 14.12.

HRMS (MALDI+) Calcd for C54H86F2N2S3 (M +) : 896.5921, Found: 896.5943.

Step2: Preparation of S4a

S4a, or 5, 6-Difluoro-4, 7-bis (5-bromo-4- (2-octyldodecyl) -2-thienyl) -2, 1, 3-benzothiadiazole, was synthesized as follows. N-Bromosuccinimide (540 mg, 3.00 mmol) was added to a mixture of S3 (1.22 g, 1.36 mmol) and silica gel (20 mg) in 20 mL of chloroform at 0℃. The reaction mixture was warmed to room temperature and stirred overnight. After washing with water, the organic phase was dried with Na₂SO₄, and the solvent was evaporated. The residue was purified with flash column chromatography (eluent: n-hexane) to get the product as an orange solid (1.42 g, 99％) .

1H NMR (400 MHz, CDCl3) δ 7.94 (s, 2H) , 2.60 (d, J ＝ 7.1 Hz, 4H) , 1.80 –1.70 (m, 2H) , 1.40 –1.15 (m, 64H) , 0.90 –0.77 (m, 12H) .

19F NMR (376 MHz, CDCl3) δ -128.10 (s, 2F) .

13C NMR (100 MHz, CDCl3) δ 149.54 (dd, J ＝ 258.9, 20.3 Hz) , 148.26, 141.70, 132.25, 130.99, 124.83, 115.13 (t, J ＝ 3.6 Hz) , 110.85 (d, J ＝ 8.6 Hz) , 38.53, 34.08, 33.35, 31.94, 30.05, 29.73, 29.69, 29.67, 29.39, 26.56, 22.71, 14.13.

HRMS (MALDI+) Calcd for C54H84Br2F2N2S3 (M +) : 1052.4131, Found: 1052.4141.

Step3: Preparation of S4b

S4b, or5, 6-Difluoro-4, 7-bis (5-bromo-4- (2-octyldodecyl) -2-thienyl) -2, 1, 3-benzothiadiazole, was synthesized by a procedure similar to the synthesis of S4a.

Step 4: Preparationof V7, V10, and V15

The polymer can be synthesized by either microwave reaction or conventional reaction.

Preparation of V7

In a glovebox protected with N₂, 0.8 mL of chlorobenzene (CB) was added to a mixture of monomer S4a (75.0 mg, 0.071 mmol) , monomer S4b (81.0 mg, 0.069 mmol) , 5, 5'-bis (trimethylstannyl) -2, 2'-bithiophene (69.1 mg, 0.140 mmol) , Pd₂ (dba) ₃ (1.1 mg, 0.002 mmol) and P (o-tol) 3 (2.4 mg, 0.008mmol) . The reaction mixture was then sealed and heated at 140℃for 2 days. The mixture was cooled to room temperature and 10 mL CB was added before precipitating with methanol. The solid was collected by filtration, loaded into an extraction thimble, and washed successively with CH₂Cl₂, CHCl₃, and toluene. The polymer was finally collected from toluene. The toluene solution was then concentrated by evaporation and precipitated into methanol. The solid was collected by filtration and dried in vacuo to get the polymer as a dark green solid (137.2 mg, 88％) .

Preparation of V10

In a glove box protected with N₂, 0.8 mL of chlorobenzene (CB) was added to a mixture of monomer S4a (49.0 mg, 0.046 mmol) , monomer S4b (157.4 mg, 0.135 mmol) , 5, 5'-bis (trimethylstannyl) -2, 2'-bithiophene (89.2 mg, 0.095 mmol) , Pd₂ (dba) ₃ (1.1 mg, 0.002 mmol) and P (o-tol) 3 (2.4 mg, 0.008mmol) . The reaction mixture was then sealed and heated at 140℃ for 2 days. The mixture was cooled to room temperature and 10 mL CB was added before precipitating with methanol. The solid was collected by filtration, loaded into an extraction thimble, and washed successively with CH₂Cl₂ and CHCl₃. The polymer was finally collected from CHCl₃. The CHCl₃ solution was then concentrated by evaporation and precipitated into methanol. The solid was collected by filtration and dried in vacuo to get the polymer as a dark green solid (155.9 mg, 75％) .

Preparation of V15

In a glove box protected with N₂, 0.4 mL of chlorobenzene (CB) was added to a mixture of monomer S4a (51.8 mg, 0.049 mmol) , S4b (19.3 mg, 0.017 mmol) , 5, 5'-bis(trimethylstannyl) -2, 2'-bithiophene (32.3 mg, 0.066 mmol) , Pd₂ (dba) ₃ (1.1 mg, 0.002 mmol) and P (o-tol) 3 (2.4 mg, 0.008mmol) . The reaction mixture was then sealed and heated at 140℃ for 1 day for microwave reaction. The mixture was cooled to room temperature and 10 mL toluene was added before precipitating with methanol. The solid was collected by filtration, loaded into an extraction thimble, and washed successively with CH₂Cl₂, CHCl₃, and toluene. The polymer was finally collected from toluene. The toluene solution was then concentrated by evaporation and precipitated into methanol. The solid was collected by filtration and dried in vacuo to get the polymer as a dark green solid (61.1 mg, 86％) .

Example 2: Synthetic Route to Z79 and Z80

The synthetic route to Z79 and Z80 is shown below in Scheme 2.

Scheme 2:

Preparationof Z79

In a glove box protected with N₂, 0.8 mL of chlorobenzene (CB) was added to a mixture of monomer Z1 (35.0 mg, 0.034 mmol) , monomer Z2 (116.4 mg, 0.102 mmol) , 5, 5'-bis (trimethylstannyl) -2, 2'-bithiophene (66.9 mg, 0.136 mmol) , Pd₂ (dba) ₃ (1.1 mg, 0.002 mmol) and P (o-tol) 3 (2.4 mg, 0.008mmol) . The reaction mixture was then sealed and heated at 140℃ for 2 days. The mixture was cooled to room temperature and 10 mL CB was added before precipitated with methanol. The solid was collected by filtration, and loaded into an extraction thimble and washed successively with CH2Cl2 and CHCl3. The polymer was finally collected from CHCl3. The CHCl3 solution was then concentrated by evaporation, precipitated into methanol. The solid was collected by filtration and dried in vacuo to get the polymer as dark red solid (76.4 mg, 50％) .

Preparationof Z80

In a glove box protected with N₂, 0.8 mL of chlorobenzene (CB) was added to a mixture of monomer Z1 (90.0 mg, 0.087 mmol) , monomer Z2 (99.8 mg, 0.087mmol) , 5, 5'-bis (trimethylstannyl) -2, 2'-bithiophene (85.6 mg, 0.174 mmol) , Pd₂ (dba) ₃ (1.1 mg, 0.002 mmol) and P (o-tol) 3 (2.4 mg, 0.008mmol) . The reaction mixture was then sealed and heated at 140℃ for 2 days. The mixture was cooled to room temperature and 10 mL CB was added before precipitating with methanol. The solid was collected by filtration, loaded into an extraction thimble, and washed successively with CH₂Cl₂ and CHCl₃. The polymer was finally collected from CHCl₃. The CHCl₃ solution was then concentrated by evaporation and precipitated into methanol. The solid was collected by filtration and dried in vacuo to get the polymer as a dark red solid (152.6 mg, 80％) .

Example 3: Synthetic Route to G1-G2

The synthetic route to G1 and G2 is shown below in Scheme 3.

Scheme 3:

Preparationof G1-G2

In a glove box protected with N₂, 0.4 mL of chlorobenzene (CB) was added to To a mixture of monomer G1 (37.7 mg, 0.023 mmol) , monomer G2 (82.0 mg, 0.047mmol) , 5, 6-difluoro-4, 7-bis (5- (trimethylstannyl) thiophen-2-yl) benzo [c] [1, 2, 5] thiadiazole (46.3mg, 0.070 mmol) , Pd₂ (dba) ₃ (1.1 mg, 0.002 mmol) and P (o-tol) 3 (2.4 mg, 0.008mmol) . The reaction mixture was then sealed and heated at 140℃ for 2 days. The mixture was cooled to room temperature and 10 mL CB was added before precipitating with methanol. The solid was collected by filtration, loaded into an extraction thimble, and washed successively with CH₂Cl₂ and CHCl₃. The polymer was finally collected from CHCl₃. The CHCl₃ solution was then concentrated by evaporation and precipitated into methanol. The solid was collected by filtration and dried in vacuo to get the polymer as a dark green solid (40.0 mg, 30％) .

Example 4: Synthetic Route to V1-V2

The synthetic route to V1 and V2 is shown below in Scheme 4.

Scheme 4:

Preparation ofV1-V2

In a glove box protected with N₂, 3.4 mL of toluene and 0.6 mL of DMF were added to a mixture of monomer V1 (34.1 mg, 0.072 mmol) , monomer V2 (38.0 mg, 0.072mmol) , 2, 6-bis (trimethyltin) -4, 8-bis (5- (2-ethylhexyl) thiophen-2-yl) benzo [1, 2-b: 4, 5-b0] dithiophene (130.2 mg, 0.144 mmol) , and Pd (PPh₃) ₄ (7.4 mg, 0.006 mmol) . The reaction mixture was then sealed and heated at 120℃ for 1 day. The mixture was cooled to room temperature and 10 mL CB was added before precipitating with methanol. The solid was collected by filtration, loaded into an extraction thimble, and washed successively with CH₂Cl₂ and CHCl₃. The polymer was finally collected from CHCl₃. The CHCl₃ solution was then concentrated by evaporation and precipitated into methanol. The solid was collected by filtration and dried in vacuo to get the polymer as a dark green solid (99.3 mg, 75％) .

Example 5: Synthetic Route to V3-V4

The synthetic route to V3 and V4 is shown below in Scheme 5.

Scheme 5:

Preparationof V3-V4

In a glove box protected with N₂, 3.0 mL of toluene was added to a mixture of monomer V3 (36.0 mg, 0.047 mmol) , monomer V4 (41.3 mg, 0.047mmol) , 2, 6-bis (trimethyltin) -4, 8-bis (5- (2-ethylhexyl) thiophen-2-yl) benzo [1, 2-b: 4, 5-b0] dithiophene (85.0mg, 0.094 mmol) , and Pd (PPh₃) ₄ (7.4 mg, 0.006 mmol) . The reaction mixture was then sealed and heated at 110℃for 1 day. The mixture was cooled to room temperature and 10 mL CB was added before precipitating with methanol. The solid was collected by filtration, loaded into an extraction thimble, and washed successively with CH₂Cl₂ and CHCl₃. The polymer was finally collected from CHCl₃. The CHCl₃ solution was then concentrated by evaporation and precipitated into methanol. The solid was collected by filtration and dried in vacuo to get the polymer as a dark green solid (117.9 mg, 72％) .

Example 6: Solar Cell Fabrication and Testing

Pre-patterned ITO-coated glass with a sheet resistance of ～15Ω per square was used as the substrate. It was cleaned by sequential ultrasonication in soap deionized water, deionized water, acetone, and isopropanol for 15 minutes at each step. The washed substrates were further treated with a UV-O₃ cleaner (Novascan, PSD Series digital UV ozone system) for 30 minutes. A topcoat layer of ZnO (Adiethylzinc solution, 15 wt％in toluene, diluted with tetrahydrofuran) was spin-coated onto the ITO substrate at a spinning rate of 5000 rpm for 30 seconds and then baked in air at 180℃ for 20 minutes. Active layer solutions (polymer: fullerene weight ratio 1: 1.2) were prepared in TMB with 2.5％of PN. The polymer concentration is 14mgml-1 for PffBT4T-25OD, 12mgml-1 for PffBT4T-50OD, 10mgml-1 PffBT4T-100OD. To completely dissolve the polymer, the active layer solution should be stirred on a hot plate at 100℃ for at least 1 hour.

Before spin coating, both the polymer solution and ITO substrate are preheated on a hot plate at 110℃. Active layers were spin-coated from the warm polymer solution on the preheated substrate in a N2 glovebox at 600 r. p. m. . The active layers were then treated with vacuum to remove the high-boiling-point additives. The blend films were annealed at 100℃ for 5 minutes before being transferred to the vacuum chamber of a thermal evaporator inside the same glovebox. At a vacuum level of 1×10-4 Pa, a thin layer (7 nm) of V2O5 was deposited as the anode interlayer, followed by deposition of 100nm of Al as the top electrode. All cells were encapsulated using epoxy inside the glovebox.

Device J–V characteristics were measured under AM1.5G (100 mW cm^-2) using a Newport Class A solar simulator (94021A, a Xenon lamp with an AM1.5G filter) in air at room temperature. A standard Si diode with KG5 filter was purchased from PV Measurements and calibrated by Newport Corporation. The light intensity was calibrated using the Si diode as a reference cell to bring spectral mismatch to unity. J–V characteristics were recorded using a Keithley 2400 source meter unit. Typical cells hada device area of 5.9 mm², defined by a metal mask with an aperture aligned with the device area. EQEs were characterized using a Newport EQE system equipped with a standard Si diode. Monochromatic light was generated from a Newport 300 W lamp source. These test protocols are exactly the same as that used in previously certified OPVs.

Example 7: Optical Characterizations

Solution UV-Vis absorption spectra at elevated temperatures were collected on a Perkin Elmer Lambda 950 UV/VIS/NIR Spectrophotometer. The temperature of the cuvette was controlled with a Perkin Elmer PTP 6+6 Peltier System, which was supplied by a Perkin Elmer PCB 1500 Water Peltier System. Before each measurement, the system was held for at least 10 minutes at the target temperature to reach thermal equilibrium. A cuvette with a stopper (Sigma Z600628) was used to avoid volatilization during the measurement.

FIG. 2 shows the UV-Vis absorption spectra of V7 at elevated temperatures in a 0.01 mg mL^-1 CB solution； FIG. 3 shows the UV-Vis absorption spectra of V10 at elevated temperatures in a 0.01 mg mL^-1 CB solution； and FIG. 4 shows the UV-Vis absorption spectra of V15 at elevated temperatures in a 0.01 mg mL^-1 CB solution.

Example 8: Mobility Characterizations

Hole mobility measurements

The holemobilities were measured using the space charge limited current (SCLC) method, employing a device architecture of ITO/V₂O₅/blend film/V₂O₅/Al. The mobilities were obtained by taking current-voltage curves and fitting the results to a space charge limited form, wherethe SCLC is described by:

where ε₀ is the permittivity of free space, ε_r is the relative permittivity of the material (assumed to be 3) , μ is the hole mobility, V_appl is the applied voltage, V_bi is the built-in voltage (0 V) , V_s is the voltage drop from the substrate’s series resistance (V_s ＝ IR, R is measured to be 10.8 Ω) and L is the thickness of the film. The J～V_appl and J^1/2～ (V_appl-V_bi-V_s) characteristics are shown in Fig. S2. By linearly fitting J^1/2 with V_appl-V_bi-V_s, the mobilities were extracted from the slope and L:

Electron mobility measurements

The electron mobilities were measured using the SCLC method, employing a device architecture of ITO/ZnO/active layer/Ca/Al. The mobilities were obtained by taking current-voltage curves and fitting the results to a space charge limited form, where the SCLC is described by:

where ε₀ is the permittivity of free space, ε_r is the relative permittivity of the material (assumed to be 3) , μ is the hole mobility, V_appl is the applied voltage, V_bi is the built-in voltage (0.7 V) , Vs is the voltage drop from the substrate’s series resistance (Vs ＝ IR, R is measured to be 10.8 Ω) and L is the thickness of the film. By linearly fitting J^1/2 with V_appl-V_bi-V_s, the mobilities were extracted from the slope and L:

The mobilities of V7, V10, and V15 are shown below in Table 1.

Table 1: Mobilities of Random Polymers V7, V10, and V15

With the information contained herein, various departures and modifications from precise descriptions of the present subject matter will be readily apparent to those skilled in the art to which the present subject matter pertains, without departing from the spirit and the scope of the below claims. As such, the present subject matter is directed to any one or more of the embodiments, or elements thereof, described herein, or permutation or combination of some or all of the embodiments, or the elements thereof, described herein. The present subject matter is not considered limited in scope to the procedures, properties, or components defined, since the preferred embodiments and other descriptions are intended only to be illustrative of particular aspects of the presently provided subject matter.

Claims

A conjugated polymer comprising five or more repeating units of the following formula

wherein

x and y are real numbers representing molar fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

each Ar₁ is independently selected from the group consisting of unsubstituted or substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein each Ar₁ may contain one to five of said arylene or heteroarylene each of which may be fused or linked； and

each Ar₂’ and Ar₂” is independently selected from the group consisting of substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein Ar₂’ and Ar₂” may contain one to five of said arylene or heteroarylene each of which may be fused or linked； wherein Ar₂’ and Ar₂” have substitution groups including but not limited to alkyl side chains； and wherein Ar₂” has a nearly identical chemical structure to Ar₂’ except substitution groups on Ar₂” differ from those on Ar₂’.
The conjugated polymerof claim 1, wherein the conjugated polymercomprises five or more repeating units of the following formula:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

each Ar₁ and Ar₂is independently selected from the group consisting of unsubstituted or substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein each Ar₁ and Ar₂ may contain one to five of said arylene or heteroarylene each of which may be fused or linked； and

each R₁ and R₂ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optically replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； wherein R₁ is not the same as R₂.
The conjugated polymerof claim 1, wherein the conjugated polymercomprisesfive or more repeating units of the following formula:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

each Ar₁, Ar₂, and Ar₃ is independently selected from the group consisting of unsubstituted or substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein Ar₁, Ar₂, and Ar₃ may contain one to five of said arylene or heteroarylene each of which may be fused or linked； and

each R₁ and R₂ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optically replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； wherein R₁ is not the same as R₂.
The conjugated polymer of claim 1, wherein the conjugated polymer comprises five or more repeating unit of the following formula:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

eachZ₁ is S or Se；

eachZ₂ is N or C-H；

each Ar₁ and Ar₂is independently selected from the group consisting of unsubstituted or substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein Ar₁and Ar₂ may contain one to five of said arylene or heteroarylene each of which may be fused or linked； and

each R₁ and R₂ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optically replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； wherein R₁ is not the same as R₂.
The conjugated polymer of claim 1, wherein the conjugated polymer comprises five or more repeating unit of the following formula:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

each Ar₁ and Ar₂is independently selected from the group consisting of unsubstituted or substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein Ar₁and Ar₂ may contain one to five of said arylene or heteroarylene each of which may be fused or linked； and

each R₁ and R₂ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optically replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； wherein R₁ is not the same as R₂.
The conjugated polymer of claim 1, wherein the conjugated polymer comprises five or more repeating unit of the following formula:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

each Ar₁ and Ar₂is independently selected from the group consisting of unsubstituted or substituted monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, wherein Ar₁and Ar₂ may contain one to five of said arylene or heteroarylene each of which may be fused or linked； and

eachR₁ and R₂ is independently selected from the group consisting of branched alkyl groups with 2-40 C atoms； wherein R₁ is not the same as R₂.
The conjugated polymer of claim 1, wherein the conjugated polymer comprises five or more repeating units of the following formula:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

eachR₁ and R₂ is independently selected from second branched alkyl groups with 2-40 C atoms； wherein R₁ is not the same as R₂； and

eachAr₁ and Ar₂is independently selected from the group consisting of:

wherein

eachZ₁, Z₂, Z₃, Z₄, Z₅, and Z₆is S, O, or Se；

each X, X₁, X₂, X₃, X₄, X₅, X₆, X₇, and X₈ is H, F, or Cl； and

each R, R₃, and R₄is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optically replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group.
The conjugated polymer of claim 5, wherein the average molecular weight of the conjugated polymer is in a range from 10,000 to 200,000 gram/mole.
The conjugated polymer of claim 1, wherein a solution of the conjugated polymer exhibits a peak optical absorption spectrum red shift of at least 50 nm when the conjugated polymer solution is cooled from 140℃ to room temperature.
The conjugated polymer of claim 1, wherein the conjugated polymercomprisesone or more repeating units selected from the following formulas:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is about 1；

n is an integer that is 5 or greater；

each Z₁, Z₂, Z₃, Z₄, Z₅, Z₆, Z₇, and Z₈ is S, O, or Se；

each X, X₁, X₂, X₃, and X₄ is H, F, or Cl； and

eachR₁, R₂, and R₃ is a second position branched side chain； whereinR₁ is not the same as R₂.
The conjugated polymer of claim 1, wherein the conjugated polymer comprises five or more repeating units of the following formula:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

eachZ₁, Z₂, Z₃, Z₄, and Z₅is S, O, or Se；

eachZ₆ is CH₂, S, or O；

eachZ₇ is H, F, or Cl； and

each R₁, R₂, and R₃ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optically replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； wherein R₂ is not the same as R₃.
The conjugated polymer of claim 11, wherein the conjugated polymer comprises five or more repeating units of the following formula:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

eachZ₆ is CH₂, S, or O；

eachZ₇ is H, F, or Cl； and

eachR₁, R₂, and R₃ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms； wherein R₂ is not the same as R₃.
The conjugated polymer of claim 11, wherein the conjugated polymer comprisesa formula selected from the group consisting of:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater； and

eachR is selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms.
The conjugated polymer of claim 11, wherein the conjugated polymer exhibits temperature-dependent aggregation properties, characterized in that a solution of the conjugated polymer exhibits a peak optical absorption spectrum red shift of at least 50 nm when the conjugated polymer solution is cooled from 140℃ to room temperature.
The conjugated polymer of claim 1, wherein the conjugated polymer comprises five or more repeating unit of the following formula:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

eachZ₁ and Z₂is S, O, or Se；

eachZ₃ is CH₂, S, or O；

eachZ₄ and Z₅ is H, F, or Cl； and

each R₁, R₂, and R₃ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms, wherein one or more non-adjacent C atoms are optically replaced by -O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-C (O) -O-, -CR⁰＝CR⁰⁰-, or -C≡C-, and wherein one or more H atoms are optionally replaced by F, Cl, Br, I, or CN or denote aryl, heteroaryl, aryoxy, heteroaryloxy, arycarbonyl, heteroarycarbonyl, arycarbonyloxy, heteroarylcarbonyloxy, aryxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R⁰ and R⁰⁰ are independently a straight-chain, branched, or cyclic alkyl group； wherein R₂is not the same as R₃.
The conjugated polymer of claim 15, wherein the conjugated polymer comprises five or more repeating unit of the following formula:

wherein

x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1；

n is an integer that is 5 or greater；

eachZ₃ is CH₂, S, or O；

eachZ₄ and Z₅ is H, F, or Cl； and

eachR₁, R₂ and R₃ is independently selected from the group consisting of straight-chain, branched, andcyclic alkyl with 2-40 C atoms； wherein R₂is not the same as R₃.
The conjugated polymer of claim 15, wherein the conjugated polymer comprises five or more repeating unit of the following formula:

wherein x and y are real numbers representing mole fractions, wherein 0<x<1, 0<y<1, and the sum of x and y is equal or less than 1.
The conjugated polymer of claim 1, wherein the conjugated polymer comprisesa formula selected from the group consisting of:

wherein

x₁ is 0.25 or 0.5 or 0.75；

x₂ and x₃ are 0.5； and

n is an integer that is 5 or greater.
An organic electronic (OE) device comprising the conjugated polymer of claim 1.
The organic electronic device of claim 19, wherein the OE device is an organic solar cell (OSC) .