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A photocrosslinkable donor, PM6-X30, has been designed by engineering the side chains of the PM6 backbone. A high PCE of 12.33% was achieved with significantly enhanced thermal stability.

We present the advancement of the photocatalytic water pollutant degradation efficiency of a porous organic polymer material via post-synthetic modification with platinum clusters.

New photocrosslinkable conjugated donor–acceptor block copolymer bearing oxetane side chains is synthesized by one-pot polymerization to improve the thermal and morphological properties.

New wide-bandgap donor-acceptor-π type conjugated polymers, PBTTT and PBTDTT, containing different π-extended conjugated bridges between benzodithiophene (BDT) as a donating unit and 3-carboxylthiophene (3CT) as a weak electron-withdrawing group, were successfully synthesized and employed as donor polymers for polymer solar cells. Thienothiophene (TT) and dithienothiophene (DTT) were selected as fused thiophene bridges for inclusion in the polymer backbone instead of a single thiophene. As a control donor polymer, PBTT containing a single thiophene bridge was also prepared. Its properties were compared with those of PBTTT and PBTDTT. As the conjugation length of the p-extended bridge (i.e., from thiophene to DTT) increased, the bandgap of the polymer slightly decreased, and the highest occupied molecular orbital level shifted to a higher-lying level. Compared to PBTT, PBTTT and PBTDTT exhibited relatively low solubility and red-shifted absorption spectra in solution states. PBTTT and PBTDTT showed strong aggregation between polymer chains, even in solution states, which were similar to the film state. Among the three copolymers, PBTTT-based non-fullerene polymer solar cells (NF-PSCs) with ITIC-Me showed a high power conversion efficiency of 7.30% with a high short circuit current density of 14.05 mA/cm2. The superior performance of the NF-PSCs based on PBTTT may be attributed to their predominant face-on orientation of polymer chains and relatively more favorable surface morphology.

Silver nanowire (AgNW) electrodes are among the most essential flexible transparent electrodes (FTEs) emerging as promising alternatives to brittle indium tin oxide (ITO) electrodes. The polymer comprising the plastic substrate to which the AgNWs are applied must also satisfy the mechanical requirements of the final device and withstand the device processing conditions. However, AgNW-based FTEs have some limitations, such as poor adhesion to coated plastic substrates, surface roughness, and difficulty in patterning. This study demonstrates a new strategy for creating AgNW-based patterned flexible poly(ethylene 2,6-naphthalate) (PEN)-based electrodes with appreciable optical and electrical properties. Introducing poly(2-hydroxyethyl methacrylate) on the PEN substrate enhanced the adhesion between the substrate and AgNWs and improved the dispersibility of the AgNWs. Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) and a small amount of 2,4-hexadiyne-1,6-diol as a photosensitizer were coated onto the AgNW layer to improve the surface roughness and achieve an effective electrode pattern. By varying the AgNW concentration, we could tune the density and thickness of the AgNWs to optimize the sheet resistance and transmittance. Optimized AgNWs with a sheet resistance of 22.6 Ω

Conjugated random terpolymers, PJ-25, PJ-50, and PJ-75 were successfully synthesized from three different monomers. Fluorine-substituted benzotriazole (2F-BTA) was incorporated into 4,8-bis(4-chlorothiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene (BDT-T-Cl) and a 1,3-bis(4-(2-ethylhexyl)thiophen-2-yl)-5,7-bis(2-alkyl)benzo[1,2-c:4,5-c']dithiophene-4,8-dione (BDD)-based alternating copolymer PM7 as a third monomeric unit. The solubility of the random terpolymers in nonhalogenated solvents increased with the number of 2F-BTA units in PM7. The random terpolymers were mixed with 3,9-bis(2-methylene-((3-(1,1-dicyanomethylene)-6,7-difluoro)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indaceno[1,2-b:5,6-b']dithiophene (IT-4F) to fabricate organic photovoltaic (OPV) cells. Among the three terpolymers and two related binary copolymers (e.g., PM7 and J52-Cl), outdoor photovoltaic (PV) cells (AM 1.5G) based on the PJ-50:IT-4F blend showed a high power conversion efficiency (PCE) of 11.34%. In addition, PJ-50 was employed as a donor in indoor PV (IPV) cells and was blended with nonfullerene acceptors, which have different absorption ranges. Among them, the PJ-50:IT-4F-based IPV device had the highest PCE of 17.41% with a Jsc of 54.75 μA cm-2 and an FF of 0.77 under 160 μW cm-2 light-emitting diode (LED) light. The terpolymer introduced in this study can be regarded as a promising material for the fabrication of outdoor PV and IPV cells with excellent performance involving the use of an eco-friendly solvent.

In this study, polyethylene 2,6-naphthalate (PEN) was selected as a substrate to fabricate a flexible conducting electrode through the solution process. The sandwiched silver nanowire (AgNW) electrode between the poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) layers fabricated on the flexible PEN substrate was successfully prepared, which exhibited a moderately high electrical conductivity and surface smoothness suitable for polymer solar cells. Notably, the sheet resistance of the PEDOT:PSS/AgNW/PEDOT:PSS film was 22 Ω/□, and it exhibited the transmittance of 82% at the wavelength of 550 nm, although PEN was used as the substrate. This electrode film can be easily employed as an anode, and when it is applied as an electrode in a polymer solar cell, it reveals a comparable performance to that of indium tin oxide-based devices. This simple and effective fabrication of flexible conductive electrodes is envisaged to contribute immensely to future research on flexible electronics and optoelectronics.

Silver nanowires (AgNWs) are one of the important flexible electrode material candidates that can replace brittle indium tin oxide (ITO). In this work, we demonstrated novel patterned sandwich-type AgNW-based transparent electrodes easily prepared using the photolithography method for application in flexible devices. A cross-linked underlayer was introduced to increase the adhesion properties between a poly(ethylene terephthalate) substrate and AgNWs, and as a result, a uniform AgNW layer was easily deposited. Finally, the AgNW layer could be easily patterned by introducing a photocross-linkable upper layer without lift-off, dry transfer, and removal methods. A mixture of poly(sodium-4-styrene sulfonate) (PSS

The development of bipolar host materials for solution-processable thermally activated delayed fluorescence organic light-emitting diodes (TADF-OLEDs) is challenging because few host materials for TADF-OLEDs have been reported. Solution-processable bipolar host materials should have good solubility in various organic solvents and should exhibit good thermal stability and film-forming properties. In this study, three bipolar host materials (i.e.Py2Cz, Py2BFCz, and Py2ICz) for solution-processable green-emitting TADF-OLEDs were synthesized by coupling 2,4-diphenylpyrimidine to mCP and modifying the carbazole-donating units in the mCP structure. Thus, the effects of different host structures on the performance of green TADF-OLEDs could be investigated. The three host materials exhibited high thermal stability and fine morphologies in film states. Therefore, all three host materials were utilized to fabricate solution-processed green TADF-OLEDs with a green-emitting dopant. Particularly, the Py2ICz-based device displayed outstanding performance with a maximum external efficiency of 24.1% because Py2ICz has superior charge balance in the emitting layer than the others. These results unambiguously demonstrated that mCP derivatives with a pyrimidine core are suitable bipolar host materials for solution-processed green TADF-OLEDs.

We successfully synthesized a crystalline main chain conjugated copolymer, P(BDBT-co-NDI2T), having BDBT donor-NDI2T acceptor heterojunctions in the film state. Interestingly, the polymer exhibited a strong absorption band from 500 to 650 nm, which overlapped well with the emission spectrum of white light-emitting diodes (LEDs) used as an indoor light source. The P(BDBT-co-NDI2T) films had a relatively smooth surface and internal morphology compared to the blend films of P(BDBT) and P(NDI2T). In particular, the Kelvin probe force microscopy data explained the increased uniformity in the distribution of the surface charge in the annealed P(BDBT-co-NDI2T) films as compared to those of the annealed blend films of P(BDBT) and P(NDI2T). Indoor photovoltaics (IPVs) produced by using the P(BDBT-co-NDI2T) synthesized in this study as an active layer showed a high power conversion efficiency of 12.70% (@500 lux) with a short circuit current density of 49.89 μA cm−2. The PCE of the P(BDBT-co-NDI2T) film-based IPVs was twice as high as that of the blend film-based IPVs and showed excellent operational stability. This study is the first time that the P(BDBT-co-NDI2T) has been applied in IPVs, which suggests the potential for their widespread use in the development of indoor organic PVs in the future.

This study demonstrated the use of a thermally crosslinked polyimide (PI) for the liquid crystal (LC) alignment layer of an LC display (LCD) cell. Polyamic acid was prepared using 4,4′-oxydianiline (ODA) and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA). The 6FDA−ODA-based polyimide (PI) prepared by the thermal cyclic dehydration of the polyamic acid (PAA) was soluble in various polar solvents. After forming a thin film by mixing trifunctional epoxide [4-(oxiran-2-ylmethoxy)-N,N-bis(oxiran-2-ylmethyl)aniline] with the 6FDA−ODA-based PAA, it was confirmed that thermal curing at −110 °C caused an epoxy ring opening reaction, which could result in the formation of a networked polyimide not soluble in tetrahydrofuran. The crosslinked PI film showed a higher rigidity than the neat PI films, as measured by the elastic modulus. Furthermore, based on a dynamic mechanical analysis of the neat PI and crosslinked PI films, the glass transition temperatures (Tgs) were 217 and 339 °C, respectively, which provided further evidence of the formation of crosslinking by the addition of the epoxy reagent. After mechanical rubbing using these two PI films, an LC cell was fabricated using an anisotropic PI film as an LC alignment film. LC cells with crosslinked PI layers showed a high voltage holding ratio and low residual direct current voltage. This suggests that the crosslinked PI has good potential for use as an LC alignment layer material in advanced LCD technologies that require high performance and reliability.

In this study, a novel wide-bandgap conjugate donor-acceptor type copolymer, PBDT-TFMTh, containing benzodithiophene (BDT) as a donor unit and trifluoromethyl (TFM)-substituted thiophene (T...

We introduce an efficient cell tracking imaging protocol using positron emission tomography (PET). Since macrophages are known to home and accumulate in tumor tissues and atherosclerotic plaque, we design a PET imaging protocol for macrophage cell tracking using aza-dibenzocyclooctyne-tethered PEGylated mesoporous silica nanoparticles (DBCO-MSNs) with the short half-life F-18-labeled azide-radiotracer via an in vivo strain-promoted alkyne azide cycloaddition (SPAAC) covalent labeling reaction inside macrophage cells in vivo. This PET imaging protocol for in vivo cell tracking successfully visualizes the migration of macrophage cells into the tumor site by the bioorthogonal SPAAC reaction of DBCO-MSNs with [18F]fluoropentaethylene glycolic azide ([18F]2) to form 18F-labeled aza-dibenzocycloocta-triazolic MSNs (18F-DBCOT-MSNs) inside RAW 264.7 cells. The tissue radioactivity distribution results were consistent with PET imaging findings. In addition, PET images of atherosclerosis in ApoE−/- mice fed a western diet for 30 weeks were obtained using the devised macrophage cell-tracking protocol.

A series of conjugated terpolymers, P2–P4, based on 4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene as the electron-donating unit, methyl-3-thiophenecarboxylate (3MT) as the weak electron-accepting unit, and 1,3-bis(2-ethylhexyl)benzo[1,2-c:4,5-c′]dithiophene-4,8-dione (BDD) as the strong electron-accepting unit were synthesized to investigate the effect of the contents of 3MT and BDD on their optical and electrochemical properties and the performance of the derived fullerene-free polymer solar cell (PSC) devices. By varying the contents of 3MT and BDD in the terpolymer structure, the solubility, absorption range, and energy levels could be efficiently tuned. Among the three terpolymers, the as-cast blend film of P3:acceptor with complementary absorption and favorable internal morphology exhibited the highest power conversion efficiency of 10.26% with a high open circuit voltage of 0.94 V and short circuit current density of 17.18 mA cm−2 in the PSC. Although the three repeating units were randomly arranged along the polymer backbone, their PSCs exhibited an excellent shelf-life of over 1000 h under ambient conditions, which is as good as those of binary D–A copolymers.

Conjugated block copolymers containing donor (D) and acceptor (A) blocks have high potential for single component polymer solar cells (SC-PSCs), but still exhibit the complexity of polymer synthesis and low device efficiency. In this research, we successfully synthesized a new fully conjugated D–A block copolymer (CDABP) by performing the entire reaction in one-pot from start to completion. This polymerization method has the advantage of saving synthesis time and cost. The photoluminescence (PL) of the CDABP film was completely quenched due to photoinduced inter/intramolecular charge transfer. A single component polymer solar cell (SC-PSC) with a CDABP film annealed at 180 °C showed the maximum power conversion efficiency (PCE) of 5.28%, a high short circuit current of 10.77 mA cm−2 and a fill factor of 62.86%, which is much higher than that (2.62%) of the device with the as-cast film. This performance can be attributed to its fine internal/surface morphology and high crystallinity of the CDABP film. In addition, transient absorption experiments on the CDABP films showed that charge carrier generation is faster and the lifetime of the generated charge carriers is longer in the annealed film than in the as-cast film. Our research explicitly provides a new structural design and simple synthesis strategy for D–A conjugate block copolymers for high-efficiency SC-PSCs.

Prostate cancer (PC) progressed to castration resistance (CRPC) is a fatal disease. CRPC tumors develop resistance to new-generation antiandrogen enzalutamide through lineage plasticity, characterized by epithelial-mesenchymal transition (EMT) and a basal-like phenotype. FOXA1 is a transcription factor essential for epithelial lineage differentiation. Here, we demonstrate that FOXA1 loss leads to remarkable upregulation of transforming growth factor beta 3 (TGFB3), which encodes a ligand of the TGF-β pathway. Mechanistically, this is due to genomic occupancy of FOXA1 on an upstream enhancer of the TGFB3 gene to directly inhibit its transcription. Functionally, FOXA1 downregulation induces TGF-β signaling, EMT, and cell motility, which is effectively blocked by the TGF-β receptor I inhibitor galunisertib (LY2157299). Tissue microarray analysis confirmed reduced levels of FOXA1 protein and a concordant increase in TGF-β signaling, indicated by SMAD2 phosphorylation, in CRPC as compared with primary tumors. Importantly, combinatorial LY2157299 treatment sensitized PC cells to enzalutamide, leading to synergistic effects in inhibiting cell invasion in vitro and xenograft CRPC tumor growth and metastasis in vivo. Therefore, our study establishes FOXA1 as an important regulator of lineage plasticity mediated in part by TGF-β signaling, and supports a novel therapeutic strategy to control lineage switching and potentially extend clinical response to antiandrogen therapies.

The photophysical properties of donor (D)-acceptor (A) polymers were studied by designing two types of polymers, (D-σ-A)n and (D-π-A)n , with non-conjugated alkyl (sp3) and π-conjugated (sp2) linkers using π-extended donor and acceptor monomers that exhibit planar A-D-A structures. The non-conjugated alkyl linker provides structural flexibility to the (D-σ-A)n polymers, while the π-conjugated linker retains the rigid structure of the (D-π-A)n polymers. Photoinduced energy transfer occurs from the large donor to acceptor units in both polymers. However, the photoinduced energy transfer dynamics are found to be dependent on the conformation of the polymers, where the difference is dictated by the types of linkers between the donor and acceptor units. In solution, intramolecular energy transfer is relatively favorable for the (D-σ-A)n polymers with flexible linkers that allow the donor and acceptor units to be proximally located in the polymers. On the other hand, intermolecular (or interchain) energy transfer is dominant in the two polymer films because the π-extended donor and acceptor units in polymers are closely packed. The structural flexibility of the linkers between the donor and acceptor repeating units in the polymers affects the efficiency of energy transfer between the donor and acceptor units and the overall photophysical properties of the polymers.

A highly crystalline conjugated donor (D)–acceptor (A) block copolymer (PBDT2T‐b‐N2200) that has good solubility in nonhalogenated solvents is successfully synthesized. PBDT2T‐b‐N2200 shows a broad complementary absorption behavior owing to a wide‐band gap donor (PBDT2T) present as a D‐block and a narrow‐band gap acceptor (N2200) present as an A‐block. Polymer solar cells (PSCs) with conjugated block copolymer (CBCP) are fabricated using a toluene solution and PSC created with an annealed film showing the highest power conversion efficiency of 6.43%, which is 2.4 times higher than that made with an annealed blend film of PBDT2T and N2200. Compared to the blend film, the PBDT2T‐b‐N2200 film exhibits a highly improved surface and internal morphology, as well as a faster photoluminescence decay lifetime, indicating a more efficient photoinduced electron transfer. In addition, the PBDT2T‐b‐N2200 film shows high crystallinity through an effective self‐assembly of each block during thermal annealing and a predominant face‐on chain orientation favorable to a vertical‐type PSC. Moreover, the CBCP‐based PSCs exhibit an excellent shelf‐life time of over 1020 h owing to their morphological stability. From these results, a D–A block copolymer system is one of the efficient strategies to improve miscibility and morphological stability in all polymer blend systems., Polymer solar cells (PSCs) with conjugated block copolymer are fabricated using a PBDT2T‐b‐N2200 solution in a nonhalogenated solvent such as toluene. PSCs created with an annealed film show the highest power conversion efficiency of 6.43% and an excellent shelf‐life time of over 1020 h owing to their morphological stability.

Two regioisomeric π-conjugated terpolymers bearing carboxylated thiophene (CT) as electron accepting unit and thienothiophene (TT) and bithiophene (BT) as electron donating units were successfully synthesized for enhancing the performance of polymer solar cells (PSCs). Regio-regular and regio-random binary copolymers based on CT and BT were also prepared as control polymers. All polymers showed unique optical properties and crystalline behaviors. Among the PSC devices fabricated in this study, the PSC based on the regio-random terpolymer (Ran-TT) and 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis (4-hexylphenyl) dithieno [2,3-d:2′,3′-d′]-s-indaceno [1,2-b:5,6b′]-dithiophene (ITIC) exhibited the highest power conversion efficiency of 5.65% with a high short circuit current density (Jsc) of 12.63 mA cm−2 and an open circuit voltage (Voc) of 0.81 V. The promising PCE value is attributed to the low-lying highest occupied molecular orbital (HOMO) of Ran-TT, effective complementary absorption spectrum and favorable internal morphology of the blend film. The internal morphology of the Ran-TT was observed to be more fine phase separation than that of the regio-regular terpolymer, facilitating exciton diffusion and dissociation in the bulk heterojunction.

We successfully synthesized a wide-bandgap p-type copolymer, 3MT-Th-S, bearing alkylthio-substituted benzodithiophene (BDT) as a donor and methyl-3-thiophenecarboxylate (3MT) as a weak electron acceptor. The electron affinity of the sulfur atom in the 2-ethylhexylthio side chains tethered to the thiophene units induces a low-lying highest occupied molecular orbital (HOMO) energy level in the corresponding polymer. 3MT-Th-S displays a strong absorption band from 400 to 600 nm, resulting in a relatively wide optical bandgap. Thin films of 3MT-Th-S exhibit a prominent face-on orientation in the out-of-plane profile, which might be a favorable orientation for moving charge carriers in the vertical direction in polymer solar cells (PSCs). Non-fullerene PSCs based on 3MT-Th-S as the donor and an n-type small molecule (ITIC, ITIC-Me, or IMIDT) were fabricated, and their performance was investigated in detail. Among the PSC devices bearing three different acceptors, the 3MT-Th-S:ITIC-based PSC exhibits the highest power conversion efficiency of 7.86% with a high short-circuit current density of 16.11 mA cm−2 and an open circuit voltage of 0.96 V. The high PCE values of PSC using the as-cast blend films of 3MT-Th-S and ITIC as an active layer without solvent additive are attributed to the low-lying HOMO level of the donor polymer, the complementary absorption behavior of the blend film, the face-on arrangement of polymer chains on the substrate, and the well-formed morphology of the binary blend film. These results clearly demonstrate that 3MT-Th-S is a promising wide-bandgap p-type polymer for high-performance fullerene-free simple PSCs.

A novel conjugated terpolymer referred to as Ter-3MTTPD was successfully synthesized using 4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene as a donor and methyl thiophene-3-carboxylate (3MT) and 5-(2-ethylhexyl)-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione (TPD) as acceptor units to investigate the effects of the terpolymer structure on the optical and electrochemical properties. The performance of an all-polymer solar cell (all-PSC) was comprehensively examined by blending the terpolymer with 2,7-bis(2-hexyldecyl)-4-(selenophen-2-yl)benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone (NDI-Se). The as-cast blend film of Ter-3MTTPD:NDI-Se exhibits the highest power conversion efficiency of 7.66% in the all-PSC. This was further supported by the results of time-resolved photoluminescence (TRPL) in Ter-3MTTPD:NDI-Se blend film states which yielded the highest PL quenching efficiency (90%) resulting from the shortest average lifetime, τave of ∼67 ps, much smaller than those of the two binary copolymer blend films (e.g., τave = 194 ps and 149 ps, respectively, for Co-3MT:NDI-Se and Co-TPD:NDI-Se). In addition, for an as-cast blend film of Ter-3MTTPD:NDI-Se in the active layer, the shelf-life (∼1000 h) of the all-PSC under ambient conditions was found to be much better compared to those of PSCs based on the other two binary copolymers, Co-3MT and Co-TPD.

A new A-b-D-b-A-type n-type small molecule, IDT-3MT, was synthesized bearing a weak acceptor thiophene-3-carboxylate bridge (3MT = b) between indacenodithiophene as a donating core and 2-(3-oxo-2,3-dihydroinden-1-ylidene)-malononitrile as the accepting end groups. Compared to IDT-T bearing a neat thiophene bridge, IDT-3MT displayed a red-shifted absorption spectrum in the film state, which is a more effective complementary absorption behavior with PBDB-T as the donor material. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels of IDT-3MT became correspondingly lower. Based on the results of grazing-incidence wide-angle X-ray scattering, the blend film of PBDB-T:IDT-3MT exhibited a more prominent face-on orientation and fine surface morphology compared with PBDB-T:IDT-T, which can facilitate charge transportation in the vertical direction. Among the two acceptors, the polymer solar cell based on a solvent additive-free as-cast PBDB-T:IDT-3MT blend film exhibited the highest power conversion efficiency of 8.40% with a high open-circuit voltage of 0.95 V and a short-circuit current density of 14.43 mA cm−2 due to the more prominent face-on orientation and favorable morphology of the blend film. According to the simple structural modification of the acceptor molecule, the ester group in the thiophene bridge played an important role toward achieving high-performance polymer solar cells.

To implement a highly flexible polymer solar cell (PSC), the mechanical properties of the material constituting the active layer are considered crucial, having a significant influence on the stability of the device. In this study, the mechanical properties of a main-chain conjugated copolymer (PBDT2T-b-PNDI2T) containing donor- and acceptor-based macromolecular species in the polymer backbone was measured and compared with that of donor and acceptor polymer blend film (P(BDT2T):P(NDI2T)). It was observed that the PBDT2T-b-PNDI2T active layer exhibited a higher crack-onset-strain and toughness compared to P(BDT2T):P(NDI2T) active layer. Correspondingly, the YTRON/polyethylene naphthalate (PEN) based flexible PSC with a PBDT2T-b-PNDI2T active layer was used, which exhibited superior mechanical stability under multiple bending conditions. The results of this study indicate that flexible PSCs with excellent durability can be developed by replacing the polymer blend used for all-PSCs with PBDT2T-b-PNDI2T as the active layer material for highly efficient future applications.

In this study, two structural isomeric polymers, TTE36 and TTE25, were synthesized and their photophysical properties and photovoltaic device performance were investigated. Because of the different linking positions of carboxylate in their thienothiophene unit, these polymers can be classified as two isomers and exhibit significantly different properties. A mixture of these two polymers was effectively applied as the donor for a highly reliable active layer in organic indoor photovoltaics (IPVs) because of its good miscibility, and especially, of its broad complementary absorption which overlapped the emission spectrum of the white light-emitting diode lamp. The ternary IPV system, achieved by mixing the wide-bandgap TTE25 polymer with the medium-bandgap TTE36 polymer, followed by blending with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), exhibited significantly enhanced open circuit voltage and short circuit current density, thus improving the power conversion efficiency (PCE) of the IPV system. Compared to the TTE36:PC61BM-binary-blend-based IPV system, the TTE36:TTE25:PC61BM (0.8:0.2:1.0 wt ratio)-ternary-blend-based IPV system exhibited an increase in PCE from 6.81% to 11.15% under 1000 lux white LED light illumination. These results indicate that the addition of TTE25 to the TTE36:PC61BM binary blend improves the morphology and light-harvesting properties of the active layer.

A novel polyethylene glycol methacrylate-grafted tetra-ethylene glycol-bridged dicationic imidazolium-based ionic liquid (PEGMA-g-TEGBDIM) was prepared by grafting tetra-ethylene glycol-bridged 1-vinyl imidazolium mesylate to the surface of cross-linked polyethylene glycol methacrylate. Its structure was characterized by FT–IR, NMR, TGA, and XPS. Due to the combination of polymer-supports and flexible imidazolium linkers, it acted as a heterogeneous catalyst to exhibit excellent catalytic activity for the efficient synthesis of N-methyl-2-nitro-aryl-benzo[4,5]imidazo[1,2-a]pyrimidine amines via the multicomponent reaction of 1H-benzo[d]imidazol-2-amine (1) and (E)-N-methyl-1-(methylthio)-2-nitroethenamine (3) with a variety of aldehydes under solvent-free conditions. Moreover, PEGMA-g-TEGBDIM was easily reused and it maintained its high catalytic activity and stability even after seven reaction-cycles. This protocol perfectly obeys the features of green chemistry, including having no waste regarding side-products, being solvent-free, and having free from column chromatographic purification.