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Organic solar cells (OSCs) have become one of the most rapidly developing research fields in the past few decades due to advantages such as low-cost manufacturing, large-area solution preparation, and compatibility with flexible substrates. Thanks to the rapid development of photovoltaic materials and device processes, the power conversion efficiencies (PCEs) of single-junction OSCs have reached 20%. Although the PCE threshold for economic up-scaling has been close to being crossed, the manufacturing cost of OSCs needs to be seriously considered. In this perspective, we mainly summarized recent advances in the innovation of cost-effective polymer donors with simple structures and structure–property relationships, as well as the guidelines for future structure designs, morphology control and the direction for the development of OSCs. [ABSTRACT FROM AUTHOR]

Designing innovative anode materials that exhibit excellent ion diffusion kinetics, enhanced structural stability, and superior electrical conductivity is imperative for advancing the rapid charge–discharge performance and widespread application of sodium-ion batteries. Hollow-structured materials have received significant attention in electrode design due to their rapid ion diffusion kinetics. Building upon this, we present a high-performance, free-standing MoO2@hollow carbon nanofiber (MoO2@HCNF) electrode, fabricated through facile coaxial electrospinning and subsequent heat treatment. In comparison to MoO2@carbon nanofibers (MoO2@CNFs), the MoO2@HCNF electrode demonstrates superior rate capability, attributed to its larger specific surface area, its higher pseudocapacitance contribution, and the enhanced diffusion kinetics of sodium ions. The discharge capacities of the MoO2@HCNF (MoO2@CNF) electrode at current densities of 0.1, 0.2, 0.5, 1.0, 2.0 and 5.0 A g−1 are 195.55 (155.49), 180.98 (135.20), 163.81 (109.71), 144.05 (90.46), 121.16 (71.21) and 88.90 (44.68) mAh g−1, respectively. Additionally, the diffusion coefficients of sodium ions in the MoO2@HCNFs are 8.74 × 10−12 to 1.37 × 10−12 cm2 s−1, which surpass those of the MoO2@CNFs (6.49 × 10−12 to 9.30 × 10−13 cm2 s−1) during the discharging process. In addition, these prepared electrode materials exhibit outstanding flexibility, which is crucial to the power storage industry and smart wearable devices. [ABSTRACT FROM AUTHOR]

All-polymer solar cells (all-PSCs) have attracted increasing attention because of their distinctive features of superior morphological stability and mechanical durability. In recent years, all-PSCs have made rapid progress, thanks to the strategy of using polymerized small molecular acceptors (PSMAs). The isomerization of monomer of fused ring small molecule acceptors (SMAs) derived from the uncertain position of the bromine atoms on terminal groups leads to regiorandom PSMAs. This isomerization effect can significantly affect the absorption spectra, frontier molecular orbital energy level, crystallinity, mobility, and orientation of PSMAs. Integrating PSMAs with regioregularity endows the materials with better absorption coefficients, superior backbone ordering and optimal blend morphology compared to those of their regiorandom counterparts. Benefitting from these advantages, many regioregular PSMAs have been reported, and the PCE of binary single junction all-PSCs has exceeded 18%. In this review, the advances of regioregular PSMAs in the past three years for high-performance all-PSCs are summarized, and the guidelines for future structure design of PSMAs are discussed. [ABSTRACT FROM AUTHOR]

Organic solar cells (OSCs) based on a symmetry-breaking strategy have received lots of attention in recent years. In addition to the symmetry-breaking innovation of acceptors, researchers have also made great contributions to the development of high-performance OSCs through continuous optimization and improvement of asymmetric donor materials. This review focuses on the design and synthesis of asymmetric donor materials and their applications in high-efficiency OSCs, as well as guidelines for future structure designs and the direction for the development of OSCs based on asymmetric polymers. [ABSTRACT FROM AUTHOR]

Short wave near-infrared (SWIR, 900–1700 nm) fluorescence imaging has attracted extensive research interest from scientists due to its high imaging quality. However, the variety of SWIR fluorescence imaging agents are quite limited and the corresponding quantum efficiency is relatively low. In this work, a novel conjugated polymer PDTSDTBT was reported, consisting of a donor unit with a tetrahedral Si (sp3) named DTS and an acceptor unit named DTBT with branched side chains. The design approach of endowing the donor–acceptor structure with the branched side chains successfully increase the fluorescence quantum efficiency. The polymer was prepared into nanoparticles by nanoprecipitation. The PDTSDTBT nanoparticles showed an absorption peak of 626 nm and fluorescence emission peak of 924 nm. The quantum efficiency of the nanoparticles is 0.53%, which is higher than that of nanotube fluorophores (0.4%). The nanoparticles also demonstrate a photothermal effect, the temperature of nanoparticles solution could reach 4 5 ∘ C under excitation by 660 nm laser. Therefore, the PDTSDTBT nanoparticles is an excellent fluorescent imaging agent with potential photothermal applications. [ABSTRACT FROM AUTHOR]

The absorption, scattering, and autofluorescence of biological tissues in short-wave infrared region (SWIR, 900–1700 nm) are relatively low, so SWIR fluorescence usually has deeper penetration into living tissues, and can show a higher signal-to-noise ratio when used for imaging in vivo. However, there are few types of organic SWIR fluorescent materials currently. In this work, p -azaquinodimethane (p -AQM) with a quinoid structure is used as the acceptor unit, and carbazole or fluorene with sp3 hybridization are used as the donor units, two conjugated polymers were synthesized. The quinone structure is conducive to the redshift of absorption and fluorescence spectra, and the sp3 hybridization structure is conducive to weakening the aggregation quenching of polymer fluorescence. PF and PCz exhibited absorption peaks of 492 nm and 508 nm, respectively. The emission peaks of the two polymers are 920 nm and 950 nm, respectively, both in the short-wave near infrared region. The quantum yield (QY) of PF and PCz is 0.4% and 0.3%, respectively. [ABSTRACT FROM AUTHOR]

NIR-II fluorescence imaging has great potential in diagnosis, but the quantum efficiency of contrast agents is an urgent problem to be solved. We synthesized two new multifunctional polymers, P-TT and P-DPP, with a tetrahedral C (sp3) and branched alkyl chains in the main chain, which were beneficial to obtain high quantum efficiency. P-TT and P-DPP showed absorption peaks of 686 nm and 763 nm, respectively, and fluorescence emission peaks of 1071 nm and 1066 nm, respectively. The photothermal effect of P-DPP can reach 52 °C, and the quantum yield reaches 1.5%, which was three times higher than that of nanotube fluorophores (quantum yield 0.4%). P-DPP is used for stable fluorescence imaging of blood vessels and photoacoustic imaging of nude mice, and successfully applied to phototherapy of nude mouse tumours. [ABSTRACT FROM AUTHOR]

Thiophene/benzene-fused π-conjugated systems are normally employed as the core units of two- and three-dimensionally expanded small molecule hole-transporting materials (HTMs) to improve their electronic and charge transport properties, whereas comparison studies between two-dimensional and three-dimensional core conformations are less reported. To further find useful clues for the design of highly-efficient small molecule HTMs and to find new core units, in this work, four HTM molecules are designed by employing triphenylene, benzotrithiophene, triptycene, and thiophenetriptycene as the core units, and simulated with density functional theory combined with the Marcus hopping model. Our results show that all the considered HTMs display appropriate molecular energy levels, less optical absorption in the visible light region and large Stokes shifts, and high hole mobilities (9.80 × 10−2 cm2 V−1 s−1). Compared with the two-dimensional core structures, the three-dimensional cores exhibit evident superiorities with the same chemical components. Meanwhile, we also find that the quasi-degenerate HOMO energy levels will be helpful to enlarge the transfer integrals between adjacent molecules, and further to promote the hole transport in HTMs. By considering the various elements simultaneously, these investigated HTMs (S-1–S-4) with thiophene- and benzene-fused cores can be expected as potential promising candidates to help create more efficient solar cells. [ABSTRACT FROM AUTHOR]

Rare earth elements are plentiful in Gannan area, China, and there is a large amount of wastewater from all kinds of mines. In this paper, rare-earth modification TiO2 composites (RE/TiO2, RE = La, Ce, Gd, Yb) was studied by theory computation and experimental performance. The prepared RE/TiO2 was investigated for the degradation of benzohydroxamic acid (BHA) as a typical residual reagent in wastewater from beneficiation. The crystallinity, morphology, specific surface area, light absorption, and composition of compound were investigated by various techniques. As a result of computation and experimentation, four different electron configurations of rare earth all retained the anatase phase of TiO2 and reduced the band gap of TiO2 to some degree compared with pure TiO2. Different rare-earth elements and calcination temperatures resulted in different removal effects on BHA. The optimum doping contents were 0.75% (500 °C), 0.20% (500 °C), 0.70% (500 °C) and 0.50% (450 °C) for La, Ce, Gd, Yb respectively. All the RE/TiO2 composites studied in this research still possessed good photoactivity after four runs, which supports the theoretical and practical basement for the photocatalytic treatment of mining and metallurgy wastewater. [ABSTRACT FROM AUTHOR]

Abstract: The development of inexpensive and effective catalysts that can produce hydrogen from methanol is attractive for the implementation of clean energy technologies. Cu-Al oxides, prepared by different methods, were tested for hydrogen production from methanol decomposition. Catalysts with spinel CuAl 2 O 4 (copper aluminate) structure as compared with non-spinel Cu-Al oxides, are more stable, and exhibit higher catalytic activity despite of their low surface area. Spinel CuAl 2 O 4 synthesized by citrate process show better performance towards methanol decomposition than that obtained by co-precipitation process. The selectivity to H 2 +CO can be improved by the impregnation of potassium in spinel CuAl 2 O 4 . However, the direct addition of potassium during the citrate process strongly inhibited the formation of CuAl 2 O 4 structure, thus leading to a low catalytic activity. CuAl 2 O 4 was found to be a reservoir of Cu, slowly releasing Cu during the catalysis of methanol decomposition and preventing Cu from quick sintering. [ABSTRACT FROM AUTHOR]

An alkyl thiophene unit was employed for the first time as a side chain substituent on an asymmetric benzodithiophene (BDT) building block in the design of novel light-harvesting polymers. A new D–A type polymer (PBDTTh–DTffBT) based on alkylthienyl asymmetric BDT and the well-known 4,7-di(thiophen-2-ethylhexyl)-5,6-difluoro-2,1,3-benzothiadiazole (DTffBT) was synthesized through a palladium catalyzed Stille coupling reaction. Efficient bulk heterojunction solar cells were fabricated by blending PBDTTh–DTffBT with PC71BM. The optimized PBDTTh–DTffBT-based photovoltaic device exhibits an open circuit voltage (VOC) of 0.87 V, a short-circuit current density (JSC) of 15.06 mA cm−2, a fill factor (FF) of 70.4% and a high power conversion efficiency (PCE) of 9.22%. The PCE was higher than the polymers which have the same backbone structure but also have the 1D or 2D symmetric BDT unit. In addition, a PCE of 7.83% with a VOC of 0.91 V, a JSC of 13.62 mA cm−2, and an FF of 63.2% was obtained for PBDTTh–DTffBT/ITIC, which is also impressive for non-fullerene PSCs. The results indicate that our design strategy of introducing an alkylthienyl unit as side chain to fabricate asymmetric BDT-based polymer is efficient in improving the photovoltaic performance. [ABSTRACT FROM AUTHOR]

Porous poly(glycidylmethacrylate-co-divinylbenzene) (PGMA-co-DVB) microspheres with an average size of 4.6 μm were prepared using a multistage emulsion polymerization method successfully and were subsequently modified by diazoresin (DR). Three kinds of porogens (toluene, cyclohexanol and dodecanol) were applied and porous microspheres with different morphologies were obtained. Porous PGMA–DVB microspheres resulting from toluene were selected for further modification with DR due to their large specific surface area and good pore structure. These microspheres were modified through the hydrolysis of epoxy groups and a photocuring reaction with DR. After treatment with UV light, the hydrogen bonding between hydrolyzed microspheres and DR was converted into covalent bonding through a unique photochemistry reaction of DR. Porous PGMA–DVB–DR microspheres were used as the stationary phase for high performance liquid chromatography (HPLC). Depending on the chemical structure of DR, the DR modified PGMA–DVB stationary phase can be used to perform mix-mode separation mechanisms, including reversed phase (RP) and hydrophilic interactions. Therefore, baseline separation of benzene analogs was achieved by using the porous PGMA–DVB–DR particles as packing materials, and the by-product of hydrophilic acetic acid was rapidly separated from the N-vinyl-1,2,4-triazole product within 5 minutes. In addition, the DR-modified particles may be expected to be an alternative tool for organic acid separation due to the presence of secondary amino groups. [ABSTRACT FROM AUTHOR]

In this paper, a series of stable Sn-containing heteroaromatic conjugated oligomers, dialkyl dithieno[3,2-b:2′,3′-d]stannole (DTSn) and stannafluorene (SnF) derivatives, were designed and synthesized employing a new synthetic route. The distinctive feature of this route is that terminal groups are linked to the backbone before the stannole cycle closed, which can avoid the cleavage of stannole in the Stille reaction. Three Sn-heteroaromatic small molecules, DTSn-1, SnF-1 and SnF-3, have been obtained and characterized. The density functional theory (DFT) calculations show that the alkyl groups are further displaced from the conjugated backbone due to the larger atomic radius of Sn, which allows a stronger π-stacking interaction to occur. Interestingly, the fluorescence intensity of DTSn-1 is increased in the presence of Al3+ due to interaction between Al3+ and Sn. However, the emissions of the three Sn-containing oligomers can be quenched by Ru3+, which renders these compounds potential candidates as fluorescence detectors for Ru3+. [ABSTRACT FROM AUTHOR]

In order to search for new wide band gap materials, vertical benzodithiophene (BDT) is designed as an electron donating unit to construct D–A type conjugated polymers. Two polymers PVB1 and PVB2 were synthesized by the Stille coupling reaction with benzothiadiazole (BT) and thieno[3,4-c]pyrrole-4,6-dione (TPD) as the accepting moieties, respectively. These polymers show wide optical band gaps of over 2.0 eV and low HOMO energy levels of below −5.5 eV. Polymer solar cell (PSC) devices were fabricated using the above polymers as donors and fullerene derivatives as acceptors. PSCs based on PVB1 and PC71BM showed a power conversion efficiency (PCE) of 2.84% with a Voc of 1.00 V, a Jsc of 6.80 mA cm−2 and a FF of 0.42. And PSCs based on PVB2 and PC71BM showed a PCE of 2.05% with a Voc of 1.09 V, a Jsc of 5.33 mA cm−2 and a FF of 0.35. Both polymers showed a high Voc of over 1.0 V, which should be attributed to the deep-lying HOMO levels of the polymers. They would be potential candidates as wide band gap components to construct tandem solar cells. [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, two dithienosilole (DTS) and bithiazole (BTz) backboned donor-acceptor (D-A) copolymers with (poly{5-(5-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b']dithiophen-2-yl)thiophen-2-yl)-4,4'-dinonyl-5'-(thiophen-2-yl)-2,2'-bithiazole} (PDTS-DTBTz)) and without (poly{5-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b']dithiophen-2-yl)-4,4'-dinonyl-2,2'-bithiazole} (PDTS-BTz)) thiophene π-bridge were synthesized to study the influence of thiophene π-bridge on their photovoltaic performances. Both polymers show similar band gap, but polymer with thiophene π-bridge (PDTS-DTBTz) has a higher molecular weight, narrower polydispersity index (PDI), more planar geometry, higher crystallinity, higher hole mobility, and better miscibility with fullerene (polymer solar cells (PSCs) acceptor). Although PDTS-BTz polymer based PSCs devices show higher open circuit voltage ( Voc), PDTS-DTBTz polymer does show higher power conversion efficiency (PCE) with improved short circuit current density ( Jsc) and fill factor (FF). The present results indicate that thiophene π-bridge does contribute to the PSCs performances of dithienosilole and bithiazole backboned copolymer. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42798. [ABSTRACT FROM AUTHOR]

ABSTRACT Three conjugated polymers, P1-P3, with dithiafulvalene (DTF) as side chains have been synthesized. All polymers have good thermal stabilities. The DTF unit could be oxidized to DTF•+ which was observed from cyclic voltammetry and ultraviolet-visible (UV-vis) spectra, and the oxidation process was independent of the conjugated backbone of the polymer. The strong π-π* transition absorbing band of the three polymers decreases gradually as increasing oxidation, and the resulting DTF•+ species give rise to an additional band at 750-1100 nm, which can be assigned to a distinguishing feature of the cation radical species. Photovoltaic device based on the blend of P2 and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) showed the power conversion efficiency of 1.05% with a fill factor of 42.8%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41508. [ABSTRACT FROM AUTHOR]

ABSTRACT The synthesis and characterization of building block of ethynylene-substituted benzo[1,2- b:4,5- b′]dithiophene (BDT), and its application in the construction of poly(aryleneethynylene)s (PAEs) are described in this article. Alkoxy-substituted BDT and thiazolothiazole are selected as the other copolymerized units, and polymers of PEBBDT and PEBTTZ were synthesized by Pd-catalyzed Sonogashira coupling reaction. These polymers showed intense interchain π-π interaction and deep HOMO levels (≤ −5.50 eV). Bulk heterojunction solar cell fabricated using PEBBDT or PEBTTZ as electron donor and PC61BM as acceptor display power conversion efficiency of 0.85 and 2.40%, respectively, under the illumination of AM1.5G, 100 mW cm−2. This study shows good prospect for the application of PAEs-type polymers in organic solar cell. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 208-215 [ABSTRACT FROM AUTHOR]

Abstract: A novel flow injection analysis (FIA) system suitable for measurements of glucose in blood serum is developed. In the proposed FIA system, a new kind of glucose sensor based on composite polymer films and well-immobilized enzyme was fabricated. An electrochemical technique of scanning electrochemical microscopy (SECM), and electrochemical impedance spectroscopy (EIS) were used for the characterization of the newly fabricated biosensor. A wide linear range of 0.1–50mM for glucose detection was reported in virtue of the new configuration of the sensor and the developed FIA system. The reproducibility of signals was quite good with relative standard deviation (RSD) values for n =4 injections (typically 5.7%). Animal blood serum was directly injected and assayed in this simulative physiological system. Good analytical recovery of glucose spiked into serum samples, with recoveries in the range of 96.7–105.0%, was exhibited. Under optimized conditions, detection of serum glucose for normal people and diabetics using our proposed method is possible. [Copyright &y& Elsevier]

A simple low-temperature solution-processed zinc oxide (ZnO) and aluminum-doped ZnO (AZO) were synthesized and investigated as an electron transport layer (ETL) for inverted polymer solar cells. A solar cell with a blend of poly(4,8-bis-alkyloxy-benzo[1,2-b:4,5-b′] dithiophene-alt-alkylcarbonyl-thieno [3,4-b] thiophene) and (6,6)-phenyl-C71-butyric acid methyl ester as an active layer and AZO as ETL demonstrates a high power conversion efficiency (PCE) of 7.36% under the illumination of AM 1.5G, 100 mW/cm 2 . Compared to the cells with ZnO ETL (PCE of 6.85%), the PCE is improved by 7.45% with the introduction of an AZO layer. The improved PCE is ascribed to the enhanced short circuit current density, which results from the electron transport property of the AZO layer. Moreover, AZO is a more stable interfacial layer than ZnO. The PCE of the solar cells with AZO as ETL retain 85% of their original value after storage for 120 days, superior to the 39% of cells with ZnO ETL. The results above indicate that a simple low-temperature solution-processed AZO film is an efficient and economical ETL for high-performance inverted polymer solar cells. Due to its environmental friendliness, good electrical properties, and simple preparation approach, AZO has the potential to be applied in high-performance, large-scale industrialization of solar cells and other electronic devices. [ABSTRACT FROM AUTHOR]

Terthiophene, including one α–α and one branching α–β connection of the thiophene units, is introduced as benzodithiophene (BDT) side chain to build a novel two-dimensional (2D) conjugated BDT block. By copolymerizing this BDT block with three electron acceptors (DTTz (bis(thiophene-2-yl)-tetrazine), DPP (diketopyrrolopyrrole), DTffBT (4,7-bis(4-hexylthienyl)-5,6-difluoro-2,1,3-benzothiadiazole)) and one electron donor (TTT (2,5-Di(2-thienyl)thiophene)), four terthiophene side-chained benzodithiophene based copolymers were synthesized. Due to the difference in electron affinity among DTTz, DPP, DTffBT and TTT, these four polymers show different UV–vis absorption spectra and optical band gaps (1.3–2.0 eV), while fortunately they all remain deep highest occupied molecular orbital (HOMO) energy levels (−5.3 to 5.6 eV) which is very favorable to high open-circuit voltage ( V oc ) polymer solar cells (PSCs). By comparing the photovoltaic properties with polymers which have same backbone but do not have the bulky 2D side group in the literatures, our polymer solar cells devices show higher V oc . Especially for PQ3 (a copolymer of benzodithiophene and diketopyrrolopyrrole), the donor photon energy loss ( E g –e V oc ) is 0.51 eV which is almost the lowest value achieved by the researchers. It can be concluded that: the bulky terthiophene side group helps to improve V oc of the PSCs devices. The overall performance of solar cells devices is correlated with the molecule conformation, polymer hole mobility and polymer/PCBM blend film morphology. [ABSTRACT FROM AUTHOR]

High-capacity electrode material is of great significance to further improve the energy density of lithium-ion batteries (LIB). Phosphorus (P) is a promising candidate for anode material due to its high theoretical capacity and low cost. However, the large volume expansion and poor conductivity restrict the practical application. Transition-metal phosphides hybrid with lamellar graphene oxide are recognized as an ideal structure to resolve these issues. Preparation of phosphides is always of great challenge with severe reaction conditions. Herein, a mild phosphorization process in low temperature plasma has been developed to synthesize lamellar Cu 3 P@RGO nanostructures at only 200 °C for 40 min. The in situ phosphatized Cu foam is a self-adaptive electrode without any conductive additives. Attributed to the unique architecture, the Cu 3 P@RGO electrode reveal a high initial coulombic efficiency of >80% and excellent long-cycling performance at a high current density of 500 mA/g (2330 mAh/g after 183 cycles). • The lamellar Cu 3 P@RGO nanostructure on Cu foam is formed in low temperature Ar–H 2 glow discharge plasma. • The in situ phosphatized Cu foam is a self-adaptive electrode without any conductive additives. • The Cu 3 P@RGO electrode reveal a high initial coulombic efficiency and excellent long-cycling performance at 500 mA/g. [ABSTRACT FROM AUTHOR]

The short-wave infrared window (SWIR, 900-1700 nm) fluorescence imaging has been demonstrated to have excellent imaging performance in signal/noise ratio and tissue penetration compared to the conventional NIR biological window (NIR-I, 700-900 nm). Conventional organic SWIR fluorescent materials still suffer from low fluorescence quantum efficiency. In this work, a donor unit with sp 3 hybrid configuration and an acceptor unit with small hindered alkyl side chains are employed to construct donor-acceptor (D-A) type conjugated polymers P1 and P2, which were substituted with one or two fluorine atoms. These structural features can alleviate the aggregation-caused quenching (ACQ) and contribute to charge transfer, resulting in a significantly improved fluorescence quantum efficiency. The SWIR fluorescent quantum efficiencies of P1 and P2 nanoparticles are 3.4% and 4.4%, respectively, which are some of the highest for organic SWIR fluorophores reported so far. Excellent imaging quality has been demonstrated with P2 nanoparticles for SWIR imaging of the vascular system of nude mice. The results indicate that our design strategy of introducing sp 3 hybrid configuration and small hindered alkyl side chains to fabricate conjugated polymers is efficient in improving the fluorescent quantum efficiency as SWIR fluorescent imaging agents for potential clinical practice., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Alkylthio groups can be used to modulate energy levels and molecular packing of organic semiconductors, which makes it important in the design of materials for organic solar cell. However, its effect has not been sufficiently exploited as most of the studies report introducing an alkylthio group to the donor unit and seldom to the acceptor unit of donor-acceptor conjugated polymers. In this report, two alkylthio-substituted polymers, namely, PBB-TSA and PBB-TSD, with benzo[1,2- d :4,5- d '] bis (thiazole) (BBT) as the acceptor unit and benzo[1,2- b :4,5- b ']dithiophene (BDT) as the donor unit, were rationally designed, synthesized, and applied in organic photovoltaics. An alkylthio side chain was substituted on the BBT-accepting unit for PBB-TSA, while for PBB-TSD, the alkylthio side chain was substituted on the BDT donor unit. PBB-TSA and PBB-TSD show upshifted and downshifted energy levels, respectively, compared to the nonsulfur-substituted material. Both polymers exhibit dominate face-on orientation, while PBB-TSD exhibits higher crystallinity compared to PBB-TSA. With the contribution of lower energy level and beneficial film morphology, the device based on PBB-TSD/IT-4F has much higher power conversion efficiency (PCE) of 14.6%, whereas the PBB-TSA blend had a lower PCE of 10.7%. 1,8-Diiodooctane can effectively optimize the blend film morphology, and the effect on device performance has also been demonstrated in detail. This result indicates that introducing an alkylthio side chain into the donor or acceptor moieties would result in materials with different energy levels and thus would be utilized to match with various acceptors, achieving optimized performance in organic solar cells.