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Facile synthesis without involvement of toxic reagents is of great significance in the practical application of photovoltaic materials. In this work, four acceptor-donor-acceptor (A-D-A) type unfused-ring acceptors (UFRAs) with stepwise extension in π-conjugation, i. e., CPFB-IC-n (n=1-4), involving cyclopentadithiophene (CPDT) and 1,4-difluorobenzene (DFB) as cores, are facilely synthesized by an atom-, step-economic and labor-saving method through direct arylation of C-H bond (DACH). Among them, CPFB-IC-4 has the longest conjugation lengths among the molecular UFRA ever reported. The dependence of optoelectronic properties and photovoltaic performances of CPFB-IC-n (n=1-4) on conjugation length were systematically investigated. CPFB-IC-2 with near zero highest occupied molecular orbital (HOMO) offsets (ΔE

In this work, we present two new electron acceptors, TriPDI and Fused-TriPDI, in which three perylene diimide (PDI) moieties are tethered to a benzotrithiophene (BTT) core via either single bonds (TriPDI) or ring-fusion (Fused-TriPDI). TriPDI connects three PDIs to BTT via carbon–carbon single bonds, resulting in a rotatable and highly twisted skeleton. Instead, Fused-TriPDI, made through oxidative ring-fusion of TriPDI, exhibits good structural rigidity and planarity, as well as effective conjugation between PDI and BTT. As a result, the fused molecule shows up-shifted energy levels, and enhanced absorption and charge mobility over the unfused one. The polymer solar cells (PSCs) with a PTB7-Th:Fused-TriPDI blend show the best power conversion efficiency of 6.19%, which is around three times higher than that with PTB7-Th:TriPDI.

Non-fullerene acceptor based organic photovoltaic devices (OPVs) reported so far are inferior to those derived from fullerenes. This increases the speculation on whether donors need to be tailored for advancing non-fullerene OPVs. We explored herein two direct arylation-derived diketopyrrolopyrrole (DPP)-based three-dimensional (3D) donors that can deliver respectable power conversion efficiencies (PCEs) of 4.64% and 4.02% with polymeric acceptor N2200 blends, surpassing those obtained from PC71BM (3.56% and 3.22%, respectively). It is found that these 3D-shaped molecular donors can yield improved photo-to-current conversion and balanced charge transport when blending with the linear N2200 polymer. This finding suggests that engineering molecular geometry can be a promising approach for developing high-performance materials.

All solution-processed flexible large area small molecule bulk heterojunction solar cells were fabricated via roll-coating technology. Our devices were produced from slot-die coating on a lab-scale mini roll-coater under ambient conditions without the use of spin-coating or vacuum evaporation methods. Four diketopyrrolopyrrole based small molecules (SMs 1–4) were utilized as electron donors with (6,6)-phenyl-C61-butyric acid methyl ester as an acceptor and their photovoltaic performances based on roll-coated devices were investigated. The best power conversion efficiency (PCE) of 1.01%, combined with an open circuit voltage of 0.73 V, a short-circuit current density of 3.13 mA cm−2 and a fill factor of 44% were obtained for the device with SM1, which was the first example reported for efficient roll-coating fabrication of flexible large area small molecule solar cells with PCE exceeding 1%. In addition, roll-coated devices based on SMs 2–4 also showed good performances with PCEs of 0.41%, 0.54%, and 0.31%, respectively. Our results prove that small molecules have the potential for use in industries for large scale production of efficient organic solar cells.

By application of clad-bonding technique of pure copper sheet and plain low carbon steel rebar Q195, the cladding wires in different diameter by drawing at room temperature have been worked. The increasing ratio of the area of grain boundary is in direct proportion to deformation approximately. The resistivity of the cladding wires go up in direct proportion to deformation because the increment of the area of grain boundary results in increment of static disfigurement to electron dispersion. When deformation is less 9.6, the relative increment of resistivity is less 1.1%, i.e. the wire is provided with good electrical conductivity. And the resistance and resistivity of the wires can be estimeted based on copper ratio of transverse section of the cladding wire and the deformation by drawing at room temperature.

The microstructure and mechanical properties of pure copper clad Aluminum wires in different diameters by drawing at room temperature were studied in this paper. The results show that the microstructure of the cladding wire by drawing at room temperature is vimineous grain as fibril shape from prime equiaxed grain. The fibril diameter is in inverse proportion to deformation and the fibril length is in direct proportion to square of deformation approximately. The ultimate tensile strength of the cladding wire by drawing at room temperature increases in direct proportion to square root of deformation, and the elongation decreases and fluctuates. Basis of the ultimate tensile strength of prime pure copper and aluminum alloy, the ultimate tensile strength of the cladding wires in different diameters can be doped out by mixed principle of composite material.

A 3D organic dye has been developed to fulfill the multi‐dimensional charge‐ and energy‐harvest in bulk‐heterojunction thin film organic solar cells to convert sunlight into electricity. In article number 1500014, H.‐Z. Chen, A. K.‐Y. Jen, and co‐workers discuss how the simple, yet delicate design strategy transforms the original planar sub‐units into a 3D molecular geometry with a compact tetrahedron core, of which four sub‐units are interlocked to reinforce structural rigidity of the molecule. The cover was designed by Xiaoming Lu.

A nonfullerene acceptor based on a 3D tetraperylene diimide is developed for bulk heterojunction organic photovoltaics. The disruption of perylene diimide planarity with a 3D framework suppresses the self-aggregation of perylene diimide and inhibits excimer formation. From planar monoperylene diimide to 3D tetraperylene diimide, a significant improvement of power conversion efficiency from 0.63% to 3.54% can be achieved.

Fracture surface and crack propagation in low temperature brittle fracture (LTBF) of an 18Cr-18Mn-0.7N high nitrogen austenitic steel (HNAS) were examined by means of scanning electronic microscopy, and compared with behaviours of LTBF of low carbon steel. Similar to BCC low carbon steel, the HNAS experienced a typical ductile-to-brittle transition (DBT) with decreasing temperature, and the appearance of the fracture surface transited from fibrous to granular. Dual-surface observation revealed that there were three types of fracture modes in LTBF of the HNAS: annealing twin boundary fracture, intergranular fracture, and transgranular fracture. The annealing twin boundary fracture facets were parallel to {111} planes, and were fairly flat and smooth, with a pattern of three sets of parallel straight-lines intersecting at 60. There were also bent steps that originated and terminated at grain boundaries. The transgranular fracture facets were coarse and uneven, with uniformly distributed small pits and partially river pattern on them. The intergranular fracture facets were smoothly curved ones on which more than three sets of parallel deformation structure trace lines were observed. Careful observation on crack propagation demonstrated that during LTBF of the HNAS, microcracks formed firstly at grain boundary and annealing twin boundary, and then these microcracks came together and coalesced to induce crack propagation through grains, resulting in a fracture appearance with shiny facets distributing in dull facets.

Non-doped type white organic electroluminescent (EL) devices have the following structure ITO/m-MTDATA (30nm) /NPB (20-dnm) /rubrene (0.1nm) /NPB (dnm) /DPVBi (20nm) /TPBi (20nm) /Alq (10nm) /LiF/Al were fabricated. The EL spectrum of the devices are dependent on the d and when d=3, the CIE coordinates of the device were well within the white region for voltage raging from 3V to 15V. This device has a luminance of 18950cd/m2 at 15V and maximum power efficiency of 5.65cd/A at 6V.

A novel derivative of oligo(phenylenvinylene) (OPV), 2,5-diphenyl -1, 4-distyrylbenzene with two trans-double bonds (trans-DPDSB), is used as a blue emitting material in blue and white organic light-emitting devices (OLEDs). Blue devices with a configuration of indium-tin oxide (ITO)/N,N´-diphenyl-N,N´-bis(1-naphthyl)-(1,1´-biphenyl)-4,4´-diamine (NPB)/ trans-DPDSB / tris (8-hydroxyquinoline) aluminum (Alq3)/LiF/Al are constructed, where NPB, Alq3 and trans-DPDSB are used as hole-transporting, electron-transporting and light-emitting layers, respectively. The color of emission is changed from blue-green to pure blue when the trans-DPDSB layer is thicker. By inserting an ultrathin 5,6,11,12-tetraphenylnaphthacene (rubrene) yellow light-emitting layer between the Alq3 and trans-DPDSB layers, white OLEDs are obtained. The maximum efficiency and luminance of the blue and white devices are 1.2, 3.0 cd/A, and 1400, 7000 cd/m2, respectively.

In this paper, we describe the performance of an organic light emitting devices〔OLEDs〕 with ITO /4,4’,4“-tris{N,- （ 3-methylphenyl ） -N-phenylamino}triphenylamine (m-MTDATA) /N,N-diphenyl-N,N-bis1-naphthyl-1,1-biphenyl-4,4-diamine (NPB) /copper phthalocyanine (CuPc) / NPB / Bathocuproine(BCP) / tris-8-hydroxyquinoline Aluminum (Alq3) / LiF/ AL structure, the CuPc inserted between the two layers of NPB as a hole-consuming layer (HCL), and the BCP as a hole-blocking layer (HBL) . The EL spectrum peak is at 430 nm, indicating that the carrier recombination is confined in the NPB layer, in additional light emission originates from NPB. Compared with the luminous efficiency of the conventional diode without CuPc layer, that of the diode with HCL has been sharply increased up to 2.62 cd /A. It suggested that the CuPc and BCP exactly function as hole-consuming and hole-blocking layers, respectively, which enhance the efficiency of carrier，s recombination and confine the excitation in the EL layer.

We have fabricated an organic light-emitting devices with high efficiency and brightness utilizing thick layer of a starburst amine compound 4,4’, 4’’-tris{N,-(3-methylphenyl)-Nphenylamin} triphenylamine (m-MTDATA) as hole injection buffer layer. The brightness and the current efficiency were comparatively improved compared with those of the device without the buffer layer. The device with 10nm m-MTDATA act as buffer layer has max brightness was 18590cd/m2 at 17 V, and the highest luminous efficiency was achieved 4.30cd/A, at 7V, which is nearly three times than that of the device without it.

we designed and fabricated a white organic light-emitting device based on{[2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9yl)ethenyl]-4H-pyran-4-ylidene] propane-dinitrile}ultrathin layer and 4,4 ´ -bis(2,2 ˊ diphenylvinyl)-1,1 ˊ -biphenyl. It shows a maximum power efficiency of 1.8l m/W at 4 V (the brightness is 51 cd/m2). Its brightness reaches 8496 cd/m2 at 16 V. And the chromaticity coordinates varying from (0.42,0.34) to (0.32,0.28) with the forward bias from 4 to 16 V are well within the white region.

The lifetime of organic light-emitting devices can be influenced by the OLED material and structure, electrode material, driving mode and so on. Among all these factors, OLED driving method has been regarded as one of the most important factors, and it is well known that ac-driving mode improves the lifetime of OLED, especially pulse-driving mode with a reversed-biased voltage on OLED. In this article, a new ac-driving mode for Active-Matrix OLED is proposed on basic fabrication of two-TFT current source pixel circuit. Simulation has been done on the pixel and 1×4 matrix circuits, and simulation results have demonstrated that OLED is in reversed-biased state during recovery time. At last, a practical peripheral circuit that can provide achieve an ac-driving mode has been designed.

In this report, an atom efficient and facile synthetic strategy for accessing multi-diketopyrrolopyrrole (DPP)-based oligomers used in solution-processed organic field effect transistors (OFETs) and organic solar cells (OSCs) has been developed. The DPP units were successfully installed onto benzene and pyrene cores via palladium-catalyzed dehydrohalogenative coupling of mono-capped DPPs with multi-bromo-benzene or -pyrene (direct arylation), affording four oligomer small molecules (SMs 1-4) containing bis-, tri-, tri-, and tetra-DPP, respectively, in high yields of 78-96%. All the designed linear or branched DPP-based oligomers exhibit broad light absorptions, narrow band-gaps (1.60-1.73 eV), deep highest occupied molecular orbital (HOMO) levels (-5.26∼-5.18 eV), and good thermal stability (Td=390-401 °C). OFETs based on SMs 1-4 showed hole mobilities of 0.0033, 0.0056, 0.0005, and 0.0026 cm2 V(-1) s(-1), respectively. OSCs based on SMs 1-4 under one sun achieved power conversion efficiencies of 3.00%, 3.71%, 2.47%, and 1.86% accordingly, along with high open-circuit voltages of 0.86-0.94 V. For OSC devices of SM 1, SM 3, and SM 4, the solvent CHCl3 was solely employed to the formation of active layers; neither high boiling point additives nor annealing post-treatment was needed. Such a simple process benefits the large-scale production of OSCs via roll to roll technology.

In the title mol-ecule, C(15)H(13)BrN(2)O(2), an intra-molecular O-H⋯N hydrogen bond influences the mol-ecular conformation; the two benzene rings form a dihedral angle of 13.6 (3)°. In the crystal, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into chains along the a axis and weak inter-molecular C-H⋯O hydrogen bonds further link these chains into layers parallel to the ac plane.

In the hydrazone mol-ecule of the title compound, C(15)H(12)ClN(3)O(4)·H(2)O, the two benzene rings form a dihedral angle of 3.6 (1)°. In the crystal structure, the solvent water mol-ecules are involved in the formation of inter-molecular N-H⋯O and O-H⋯N hydrogen bonds, which link the mol-ecules into double ribbons extending along the b axis. Inter-molecular π-π inter-actions between the aromatic rings [centroid-centroid distances = 3.712 (3) and 3.672 (3) Å] link these ribbons further into layers parallel to the ab plane.

In the title compound, C15H13BrN2O4·CH4O, the two benzene rings form a dihedral angle of 3.2 (2)°. An intra­molecular O—H⋯N hydrogen bond is observed. In the crystal structure, mol­ecules are linked through O—H⋯O and N—H⋯O hydrogen bonds, forming a two-dimensional network parallel to (10\overline{1}).

C16H17N3O2 ,m onoclinic, P21/n (no. 14), a =1 0.825(3) A, b =8 .916(2) A, c =1 5.310(2) A, / =1 06.291(2)°, V =1 418.3 A 3 , Z =4 , Rgt(F) =0 .0473, wRref(F 2 ) =0 .1344, T =2 98 K. Source of material Th ec ompoun dw as prepared by the condensation reaction of 3hydroxy benzaldehyde (1 mm ol, 0.122 g) and 4dimethylaminobenzohydrazide (1 mmol, 0.179 g) in anhydrous methanol (30 ml )a ta mbient temperature. Colourless blockshaped single crystals suitable for X-ray structural determination were obtained by slow evaporation of the solution for aw eek. Experimental details H(2) wa sl ocated from ad ifferenc eF ourier ma pa nd refined isotropically, with the N–H distance restrained to 0.90(1) A. The remaining Ha tom sw ere positioned geometrically and constrained to ride on their parent atoms, with C–H distances of 0.930.96 A, O–H distance of 0.82 A, and with Uiso(H) =1 .2Ueq(C) and 1.5Ueq (O1 and Cmethyl). Discussion Considerable attention has been focused on hydrazones and their medicinal applications [1-5] .T he study of the crystal structures of such compounds is of particular interest [6-8]. As ac ontinuation of our work on such compounds, we report herein the crystal structure of the title hydrazone derivative. The molecular structure of the title compound is shown in the figure. The dihedral an

C21H21N3O2, monoclinic, P21/n (no. 14), a = 10.111(2) Å, b = 6.623(2) Å, c = 26.969(2) Å, β = 98.241(2)°, V = 1787.3 Å3, Z = 4, Rgt(F) = 0.0578, wRref(F2) = 0.1544, T = 298 K.

C21H21N3O2 ,m onoclinic, P21/c (no. 14), a =5 .0165(5) A, b =1 3.148(1) A, c =2 6.705(2) A, / =9 0.198(1)°, V =1 761.4 A 3 , Z =4 , Rgt(F) =0 .0656, wRref(F 2 ) =0 .1768, T =2 98 K. Source of material Th ec ompoun dw as prepared by the condensation reaction of 2methoxy-1-naphthaldehyde (1mmol, 0.186 g) and 4dimethylaminobenzohydrazide (1mmol, 0.179 g) in anhydrous methanol (30 ml )a ta mbient temperature. Colourless blockshaped single crystals suitable for X-ray structural determination were obtained by slow evaporation of the solution for aw eek. Experimental details H(2) wa sl ocated from ad ifferenc eF ourier ma pa nd refined isotropically, with the N–H distance restrained to 0.90(1) A. The remaining Ha tom sw ere positioned geometrically and constrained to ride on their parent atoms, with C–H distances of 0.930.96 A, and with Uiso(H) =1 .2Ueq(C) and 1.5Ueq(Cmethyl).

C16H17BrN2O5, triclinic, P1 (no. 2), a = 6.934(1) A, b = 8.339(2) A, c = 14.619(2) A, 1 = 99.246(2)°, / = 91.861(2)°, . = 102.506(2)°, V = 812.5 A, Z = 2, Rgt(F) = 0.0382, wRref(F ) = 0.0907, T = 298 K.

A diketo-pyrrolo-pyrrole (DPP) oligomer containing three DPP cores (Ph4Th4(DPP)3) was synthesized via direct arylation of C-H bonds (DACH). Ph4Th4(DPP)3 has good solubility in many organic solvents, and shows a broad absorption band from the visible to near-infrared region as well as a field-effect hole mobility as high as 0.006 cm(2) V(-1) s(-1). Solution-processed bulk heterojunction organic solar cells based on blends of Ph4Th4(DPP)3 as electron donor and fullerene derivative as electron acceptor were fabricated. An optimized power conversion efficiency of 3.76% with a high open-circuit voltage of 0.85 V was achieved after finely tuning the morphology by changing the blend ratio and by adding additives. These results indicate that DACH is an effective way to produce π-conjugated oligomers for organic solar cells.

Diketopyrrolopyrrole (DPP) derivatives are an important class of high-performance pigment used in inks, paints, plastics, and organic electronics. Until now, DPP derivatives containing sophisticated aryl units at the DPP core have usually been obtained via Suzuki, Stille, or Negishi cross-coupling reactions, which require organometallic precursors. In this work, a series of DPP-based π-conjugated molecules bearing diverse aryl substituents on the thiophene- or benzene-DPPs were facilely synthesized in moderate to excellent yields through the Pd-catalyzed direct arylation of C–H bonds. The synthetic procedures feature advantages over traditional C–C cross-coupling reactions such as: (1) avoidance of the use of organometallic reagents in the starting materials leading to simpler byproducts and higher atom economy, (2) fewer synthetic steps, (3) higher yields, (4) better compatibility with chemically sensitive functional groups, and (5) simpler catalytic systems free of phosphine ligands. These advantages make the present protocol an ideal and versatile strategy for the synthesis of DPP derivatives, especially for structurally complicated DPPs that may possess chemically sensitive functionalities. The optical and electrochemical properties of the synthesized DPPs (17 compounds) were systematically investigated using UV-vis spectroscopy, steady-state fluorescence spectroscopy, and cyclic voltammetry (CV).

In the title compound, C15H13FN2O, the dihedral angle between the benzene rings is 16.9 (2)°. The F atom and the O atom are in a syn conformation. In the crystal, molecules are linked by N—H...O hydrogen bonds to generate C(4) chains propagating along the b-axis direction.

In the title compound, C15H13N3O3, the dihedral angle between the benzene rings is 1.01 (3)° and that between the nitro group and its attached ring is 5.99 (15)°. In the crystal, molecules are linked by N—H...O hydrogen bonds generating C(4) chains along [010].

In the mol-ecule of the title compound, C(17)H(13)N(3)O(2), the naphthyl ring system and the pyridine ring form a dihedral angle of 12.2 (3)°. An intra-molecular O-H⋯N hydrogen bond generates a six-membered ring with an S(6) ring motif. This also contributes to the relative overall near planarity of the mol-ecule [r.m.s. deviation of all 22 non-H atoms = 0.107 (5) Å]. In the crystal, mol-ecules are linked through inter-molecular N-H⋯N hydrogen bonds, forming chains along the a axis.

In the hydrazone molecule of the title compound, C(13)H(9)I(2)N(3)O(2)·CH(3)CN, the aromatic rings form a dihedral angle of 9.4 (3)°. In the crystal structure, inter-molecular I⋯N inter-actions [3.099 (4) Å] link hydrogen-bonded aggregates of the hydrozone and solvent molecules related by translation along the b axis into chains. An intramolecular O-H⋯N hydrogen bond forms an S(6) ring.

In the title compound, C(19)H(16)N(2)O(2), the benzene ring and the naphthyl ring system form a dihedral angle of 8.7 (3)° and an intra-molecular O-H⋯N hydrogen bond generates an S(6) ring. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, forming C(4) chains propagating in [001].

In the title compound, C(19)H(16)N(2)O(2), the benzene ring and naphthyl ring system are inclined at a dihedral angle of 16.1 (3)°. An intra-molecular O-H⋯N hydrogen bond influences the mol-ecular conformation. In the crystal, mol-ecules are linked through N-H⋯O hydrogen bonds into chains running along the a axis.

In the title compound, C(15)H(13)BrN(2)O(3), the two benzene rings form a dihedral angle of 16.9 (2)°. An intra-molecular O-H⋯N hydrogen bond affects the mol-ecular conformation. In the crystal structure, mol-ecules are linked through N-H⋯O hydrogen bonds into chains running along the a axis.

In the title compound, C(15)H(13)BrN(2)O(3), the mol-ecule adopts an E configuration about the C=N bond and the two benzene rings form a dihedral angle of 20.3 (3)°. In the mol-ecule, there are two intra-molecular hydrogen bonds, viz. O-H⋯N and N-H⋯O, involving the hy-droxy substituent, the meth-oxy O atom and the hydrazide NH group and N atom. In the crystal structure, mol-ecules are linked through N-H⋯O hydrogen bonds, forming chains propagating along [010].

In the title compound, C(14)H(11)N(3)O(4), the two benzene rings form a dihedral angle of 45.3 (3)°. The nitro group is twisted out of the attached ring by a dihedral angle of 37.5 (3)°. In the crystal structure, mol-ecules are linked into a two-dimensional network parallel to (100) by O-H⋯O and N-H⋯O hydrogen bonds.

In the title compound, C(17)H(19)N(3)O(2), the two benzene rings form a dihedral angle of 89.2 (2)°. In the crystal structure, mol-ecules are linked through N-H⋯O hydrogen bonds, forming C(4) chains running along the c axis.