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A1-D-A2-D-A1 type of structured BT-CMCN, which consists of an electron-deficient benzothiadiazole (BT) (A2), electron-rich thiophene (D) and electron-deficient dicyanomethylene-4H-chromene (CMCN) (A1) moiety, was synthesized. BT-CMCN showed pretty good thermal stability with the onset of decomposition temperatures of 304 °C at 5 wt % loss. The optical and electrochemical properties were investigated that reveal the HOMO/LUMO energy levels of BT-CMCN are −5.29 eV/−3.58 eV with the optical band gap of 1.72 eV. The HOMO/LUMO energy levels of BT-CMCN are higher than those of PC71BM. The best performance based on BT-CMCN/PC71BM in inverted-type organic solar cells (OSCs) exhibits the PCE of 0.69% with a short-circuit current density (Jsc) of 2.03 mA/cm2, Voc of 0.79 V, and fill factor (FF) of 42.7%. [ABSTRACT FROM AUTHOR]

A synthesized of acceptor-donor-acceptor (A-D-A) type oligomer based on benzodithiophene (BDT) as a donor (D) unit and phenylisoxazol (OX) as an acceptor (A) is to investigate the effect of combination between the strong electron donor and a strong electron acceptor. In addition, we introduce hexylthiophene (HT) ring as a π-bridge to extend the effective conjugation length and increase the solubility. Here we report the performance of 2,6-(4-(thiophen-2-yl)methylene)-3-phenylisoxazol-5(4H)-one)-4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b′]dithiophene) (BDT-HTOX) employing as the electron donor in the inverted organic solar cells and PC71BM as the electron acceptor unit. UV-Vis absorption and electrochemical measurements investigated the optoelectronic properties that revealing the HUMO/LUMO level at −3.72 eV/−5.44 eV with an optical band gap of 1.72 eV for BDT-HTOX. Maximum power conversion efficiency based on BDT-HTOX is showed up to 0.80% with a short-circuit current density (Jsc) of -3.26 mA/cm2, Voc of 0.88 V, and fill factor (FF) of 27.9% using chlorobenzene as a solvent for solution processed organic solar cells. [ABSTRACT FROM AUTHOR]

An acceptor-donor-acceptor (A-p-D-p-A) type oligomer based on benzothiadiazole and 2,7 carbazole, 2,7-Bis(5-{7–2[-(4-decyloxy-phenyl)-vinyl]-benzo[1,2,5]thiadiazol-4-yl}-thiophen-2-yl)-9-(2-octyl-dodecyl)-9 H-carbazole (CzBT-DP), is synthesized by the Suzuki Coupling reaction. In addition, to extend the effective of conjugated length, we introduce thiophene (T) ring as a p-bridge and stilbene in the end of the conjugated chain. Optical, electrical and thermal properties and photovoltaic performances ofCzBT-DPis systematically investigated. UV-vis absorption spectra and cyclic voltammograms (CV) reveal that HOMO/LUMO level ofCzBT-DPis −5.37 eV/−3.38eV with an optical band gap of 1.99 eV, respectively, due to the addition of conjugated chain using stilbene compound system. The HOMO energies ofCzBT-DPwere calculated from the measured onset potential of oxidation by assuming the energy level of ferrocene (Fc) as −4.8 eV by CV. Addition of thiophene affects the HOMO level which makesCzBT-DPhas high-lying HOMO level. Due to higher LUMO energy values above 0.3 eV than PC71 BM,CzBT-DPcould be applied to BHJ OSCs as the donor [1]. Inverted type organic solar cells (OSCs) with a configuration of ITO/ZnO/CzBT-DP:PC71BM/MoO3/Al are fabricated. Figure 1 shows the current density-voltage (J-V) characteristics of the optimized BHJ OSCs based onCzBT-DP:PC71BM blend ratios from 3:2 to 3:6 (w/w). Maximum power conversion efficiency (PCE) is 0.64% with a short-circuit current density (Jsc) of 1.78 mA/cm2,Vocof 0.94 V, and fill factor (FF) of 38.3%. The best blend ratio betweenCzBT-DPand PC71BM having the best PCE appeared at 3:3 (w/w). [ABSTRACT FROM PUBLISHER]

An acceptor-donor-acceptor (A-D-A) type oligomer based on benzothiadiazole and phenothiazine, 3,7-bis-[5-(7-methyl-benzo[1,2,5]thiadiazol-4-yl)-thiophen-2-yl]-10-(2-octyl-dodecyl)-10H-phenothiazine (PTBT), is synthesized by the Suzuki Coupling reaction. In addition, we introduce thiophene (T) ring as a π-bridge to extend the effective conjugation length. To investigate the effect of combination between strong electron donor and strong electron withdrawing on the diverse properties of conjugated oligomer on PTBT, optical and electrochemical properties are examined using UV-Vis absorption spectra and cyclic volatommograms (CV) that revealing HOMO/LUMO level at −5.36 eV/−3.18 eV with an optical band gap of 2.18 eV, respectively. Inverted-type organic solar cells (OSCs) with a configuration of ITO/ZnO/PTBT:PC71BM/MoO3/Al are fabricated. Maximum power conversion efficiency of the organic solar cells (OSCs) based on PTBT is showed up to 0.44% with a short-circuit current density (Jsc) of – 1.63 mA/cm2,Vocof 0.87 V, and fill factor (FF) of 30.9%. [ABSTRACT FROM PUBLISHER]

A series of small-molecules (SMs) based on coplanar perylene unit coupled with diketopyrrolopyrrole chromophoric core exhibit broad absorption in the range of 500–800 nm and low bandgap energise of 1.6–1.7 eV. The power conversion efficiency approximately reach at 0.4% under 1.5 G illumination is achieved for organic solar cells based on a small-molecule bulk heterojunction system consisting of SMs as a donor and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as an acceptor. [ABSTRACT FROM AUTHOR]

Solution-processable organic semiconductor nanowires (NWs) offer a potentially powerful strategy for producing large-area printed flexible devices. Here, the fabrication of lateral organic solar cells (LOSC) using solution-processed organic NW blends on a flexible substrate to produce a power source for use in flexible integrated microelectronics is reported. A high photocarrier generation and an efficient charge sweep out are achieved by incorporating 1D self-assembled poly(3-hexylthiophene) NWs into the active layer, and an MoO3 interfacial layer with high work function is introduced to increase the built-in potential. These structures significantly increase the carrier diffusion/drift length and overall generated photocurrent in the channel. The utility of the LOSCs for high power source applications is demonstrated by using interdigitated electrode patterns that consist of multiple devices connected in parallel or in series. High photovoltage-producing LOSC modules on plastic substrates for use in flexible optoelectronic devices are successfully fabricated. The LOSCs described here offer a new device architecture for use in highly flexible photoresponsive energy devices. [ABSTRACT FROM AUTHOR]

A novel donor-π bridge - acceptor (A)-π bridge - donor type molecule (PCTDPP20) with planar core based on diketopyrrolopyrrole (DPP) and carbazole is synthesized by the Suzuki coupling reaction. We introduce phenyl rings to extend the π-conjugation length as a π-bridge. The HOMO and LUMO energy levels of PCTDPP20 are −5.13 and −3.57 eV, respectively. From the UV-Vis spectra, we confirm that the maximum absorption wavelgth (λmax) of the PCTDPP20 annealed film at 100°C is red-shifted about 30 nm and the absorption intensity at 600 ∼ 650 nm increase compared to that of as-spun film. And the OFET based on PCTDPP20 annealed at 100°C exhibits a highest hole mobility of 1.6 × 10−4cm2/Vs together with a Ion/Ioffratio of 1.0 × 104and a Vthof 14 V. Also, the photovoltaic properties are investigated in the device structure of ITO/PEDOT:PSS/PCTDPP20:PC60BM (with different blend ratios)/Al. Among the OSCs, PCTDPP20:PCBM weight ratio of 1:0.8 and termal annealing process at 100°C for 10 min are optimum belnd ratio and temperature, respectively. This device shows the best performance with a highest PCE of 0.95% a Jscof −2.69 mA/cm2, a Vocof 0.79 V and a fill factor of 44.5%. [ABSTRACT FROM AUTHOR]

Understanding the vertical phase separation of donor and acceptor compounds in organic photovoltaics is requisite for the control of charge transport behavior and the achievement of efficient charge collection. Here, the vertically phase-separated morphologies of poly(3-hexylthiophene):[6,6]phenyl-C61-butyric acid methyl ester (P3HT:PCBM) blend films are examined with transmission electron microtomography, dynamic secondary ion mass spectroscopy, and X-ray photoelectron spectroscopy. The 3D morphologies of the processed films are analyzed and how the solvent additive causes vertical segregation is determined. The photocurrent-voltage characteristics of the vertically segregated blend films are strongly dependent on the 3D morphological organization of the donor and acceptor compounds in the photoactive layer. This dependence is correlated with asymmetric carrier transport at the buried interface and the air surface in the vertically segregated blend films. [ABSTRACT FROM AUTHOR]

Large‐area, flexible, lateral organic solar cells are demonstrated for the first time. In article number 1401317, Kilwon Cho and co‐workers demonstrate that the incorporation of 1D organic semiconductor nanowires in the photoactive layer achieves efficient charge sweep‐out to asymmetric electrodes in lateral solar cells. An interdigitated solar module to amplify power generation can be fabricated on a plastic substrate and mechanically deformed without loss of performance. [ABSTRACT FROM AUTHOR]

The three‐dimensional characterization of the bulk heterojunction photoactive layer is essential for the systematic optimization of film morphologies in the development of highly efficient organic photovoltaic (OPV) devices. In article 1300612, Kilwon Cho and co‐workers report on the additiveassisted vertical phase separation of the photoactive layer in organic solar cells, which is strongly correlated with the asymmetric electrical behavior and photovoltaic parameters. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel methodology to obtain soluble solid-state metal oxide precursor (PTO). • Highly pure, stable and monodispersed PTO was obtained. • PTO exhibits excellent solution processibility and optical/electrical properties. • Optoelectronic devices made with PTO provides improved performance and stability. Metal suboxides (MOs) are among the most attractive interfacial materials owing to their outstanding functionality and excellent electrical and optical properties. However, the limitations of solution processability and ambient stability of the precursor hinder their widespread application. In this study, we developed a novel methodology for the solidification of sol–gel-derived MO-based organic complexes without affecting the properties of the MO products. By controlling the polarity of a conventional sol–gel derived titanium suboxide solution (STO) with organic functional side groups, we can easily obtain a nearly monodispersed solid-state precursor of STO (PTO) with excellent solubility in alcohols. PTO demonstrates ideal optical and electrical properties as an electron transport layer (ETL) with a significantly enhanced stability due to the elimination of the reactive residue. Owing to the optical, electrical, and excellent film-forming properties of PTO, organic and perovskite solar cells with PTO exhibit drastically improved performances and stability. Thus, a PTO-based ETL was successfully fabricated on various active layers, including those prepared from organic and perovskite materials, demonstrating the universality of PTO. [ABSTRACT FROM AUTHOR]

Highlights: [•] The amphiphilic block copolymer facilitated the self-organization of P3HT. [•] The self-organization induced the formation of a higher-order lamellar structure. [•] The higher-order lamellar structure enhanced the charge transport properties. [•] The improved charge transport was resulted in the increased current density. [ABSTRACT FROM AUTHOR]

A series of novel alternating polymers, namely P(BDTO-TTFQ) , P(BDTT-TTFQ) , and P(BDTSi-TTFQ) , incorporating electron-rich benzo [1,2-b:4,5-bʹ]dithiophene (BDT) derivatives, namely 4,8-bis(2-butyloctyloxy)benzo [1,2-b:4,5-bʹ]dithiophene (BDTO), 4,8-bis(5-(2-butyloctyl)thiophen-2-yl)benzo [1,2-b:4,5-bʹ]dithiophene (BDTT), and 4,8-bis(triisopropylsilylethynyl)-benzo [1,2-b:4,5-ʹ]dithiophene (BDTSi), as well as electron-deficient 5,8-bis(5-(4-hexylthiophen-2-yl)thiophen-2-yl)-2,3-didodecyl-6,7-difluoroquinoxaline (TTFQ) units were prepared. The photo-physical, electrochemical, crystallinity, curvature, charge transport, and photovoltaic properties of the TTFQ-based polymers were investigated thoroughly and compared briefly to those of structurally similar 2,3-didodecyl-6,7-difluoro-5,8-di(thiophen-2-yl)quinoxaline (TFQ)-based polymers, namely P(BDTO-TFQ), P(BDTT-TFQ), and P(BDTSi-TFQ), containing BDTO, BDTT, and BDTSi. This study confirmed that the incorporation of additional π˗bridges (3-hxeylthiophene) between the BDT and TFQ units of P(BDTO-TFQ), P(BDTT-TFQ), and P(BDTSi-TFQ) do not significantly alter the properties of the polymers P(BDTO-TFQ) and P(BDTT-TFQ), but do significantly alter the properties of P(BDTSi-TFQ). Consequently, the polymers P(BDTO-TTFQ) and P(BDTT-TTFQ) exhibit comparable power conversion efficiencies (PCEs, 3.99% and 6.69%, respectively) to those of P(BDTO-TFQ) and P(BDTT-TFQ) (3.49% and 7.06%, respectively), but P(BDTSi-TTFQ) exhibits a significantly improved PCE of 6.21% compared to that of P(BDTSi-TFQ) (0.75%). The photovoltaic performance of quinoxaline-based polymers was greatly increased via the side and main chain engineering of the polymer backbone, and the PCE was maximum enhanced from 0.8% to 6.2%. Image 1 • Qunoxaline-based three new polymers with different substituent were prepared. • The calculated optical bands were 1.87 eV, 1.84 eV and 1.85 eV, respectively. • The determined HOMO levels were −5.24 eV, −5.36 eV and −5.48 eV, respectively. • The maximum PCEs of NFA OSCs were 3.99%, 6.69% and 6.21%. • π-bridge engineering on the polymer backbone with were greatly alter their properties. [ABSTRACT FROM AUTHOR]