Jiuxing Wang

Bio: Jiuxing Wang is an academic researcher from Qingdao University. The author has contributed to research in topics: Organic solar cell & Polymer solar cell. The author has an hindex of 13, co-authored 32 publications receiving 512 citations. Previous affiliations of Jiuxing Wang include Chinese Academy of Sciences.

Extending π-Conjugation System with Benzene: An Effective Method To Improve the Properties of Benzodithiophene-Based Polymer for Highly Efficient Organic Solar Cells

Abstract: To obtain a polymer based on benzodithiophene (BDT) owning both a largely extended π-conjugation system and a low-lying highest occupied molecular orbital (HOMO), a polymer (PBDTBzT-DTffBT) containing benzothienyl-substituted BDT is designed and synthesized. Compared with the polymer (PBDTT-DTffBT) based on thienyl-substituted BDT, PBDTBzT-DTffBT exhibits better thermal stabilities, red-shifted absorption spectra, and stronger intermolecular interactions. The HOMO and lowest unoccupied molecular orbital (LUMO) in PBDTBzT-DTffBT are decreased by 0.11 and 0.13 eV, respectively, which should be attributed to the contribution of the electron-withdrawing group benzene. Polymer solar cells (PSCs) based on PBDTBzT-DTffBT and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) exhibit a maximum power conversion efficiency (PCE) of 7.30% with a large open-circuit voltage of 0.90 V under AM 1.5G illumination (100 mW/cm2). The PCE is 36% higher than that of the PSCs derived from PBDTT-DTffBT. These findings provide ...

Recent advances, challenges and prospects in ternary organic solar cells

Abstract: The past decade has seen a tremendous development of organic solar cells (OSCs). To date, high-performance OSCs have boosted power conversion efficiencies (PCEs) over 17%, showing bright prospects toward commercial applications. Compared with binary OSCs, ternary OSCs, by introducing a third component as a second donor or acceptor into the active layer, have great potential in realizing outstanding photovoltaic performance. Herein, a comprehensive review of the recent advances of ternary solar cells is presented. According to the chemical components of active layer materials, we classify the ternary systems into four categories, including polymer/small molecule/small molecule, polymer/polymer/small molecule, all-polymer and all-small-molecule types. The relationships among the photovoltaic materials structure and weight ratio, active layer morphology and photovoltaic performance are systematically analyzed and summarized. The features and design strategies of each category are also discussed and summarized. Key issues and challenges faced in ternary OSCs are pointed out, and potential strategies and solutions are proposed. This review may provide guidance for the field of ternary OSCs.

Balancing High Open Circuit Voltage over 1.0 V and High Short Circuit Current in Benzodithiophene-Based Polymer Solar Cells with Low Energy Loss: A Synergistic Effect of Fluorination and Alkylthiolation

Abstract: DOI: 10.1002/aenm.201701471 from over 11%[1,2] and 12%[3] up to over 13% now[4] in either tandem or single junction solar cells from benzo[1,2-b:4,5b′] dithiophene (BDT)-based polymers as the donor material in photovoltaic (PV) devices, their limiting open-circuit voltage (Voc, below 1.00 V) is still one of the key obstacles to achieve ideally high PV performance with minimized trade-off on another characteristic features of the OPV devices, i.e., the short-circuit current density (Jsc). For the first two single junction polymer solar cells (PSCs) with PBDB-T/3,9-bis(2-methylene-(3-(1,1dicyanomethylene)-indanone))-5,5,11,11tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′d′]-s-indaceno[1,2-b:5,6-b′]dithiophene (ITIC) and PBDT-T/IT-M as active layer materials, respectively, their photon energy loss (defined as ELoss = Eg − eVoc, whereas Eg refers to the band gap energy difference between the energy level of highest occupied molecular orbital (HOMO) and lowest unoccupied mole cular orbital (LUMO)) has been pronounced as 0.66 and 0.69 eV, respectively, which is still above the empirically optimized level of 0.60 eV.[7] Despite their breaking PCE values, these nonideally low ELoss still reflect the imperfect molecular design of the PBDB-T backbone structure for ideal control on their HOMO/LUMO levels. ELoss, Eg, Voc, and Jsc for [6,6]-phenylC71-butyric acid methyl ester (PC71BM)/PSCs from BDT and/ or 2′-ethylhexyl-3-fluorothieno[3,4-b]thiophene-2-carboxylate (TT, Based on the most recently significant progress within the last one year in organic photovoltaic research from either alkylthiolation or fluorination on benzo[1,2-b:4,5-b′]dithiophene moiety for high efficiency polymer solar cells (PSCs), two novel simultaneously fluorinated and alkylthiolated benzo[1,2-b:4,5-b′] dithiophene (BDT)-based donor–acceptor (D–A) polymers, poly(4,8-bis(5′-((2′′-ethylhexyl)thio)-4′-fluorothiophen-2′-yl) benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl)-alt-2′-ethylhexyl-3-fluorothieno[3,4-b] thiophene-2-carboxylate (PBDTT-SF-TT) and poly(4,8-bis(5′-((2′′-ethylhexyl) thio)-4′-fluorothiophen-2′-yl)benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl)-alt-1,3bis(thiophen-2-yl)-5,7-bis(2-ethylhexyl)benzo[1,2-c:4,5-c′]dithiophene-4,8-dione (PBDTT-SF-BDD), namely, via an advantageous and synthetically economic route for the key monomer are reported herein. Synergistic effects of fluorination and alkylthiolation on BDT moieties are discussed in detail, which is based on the superior balance between high Voc and large Jsc when PBDTTSF-TT/PC71BM and PBDTT-SF-BDD/PC71BM solar cells present their high Voc as 1.00 and 0.97 V (associated with their deep highest occupied molecular orbital level of −5.54 and −5.61 eV), a moderately high Jsc of 14.79 and 14.70 mA cm−2, and thus result a high power conversion efficiency of 9.07% and 9.72%, respectively. Meanwhile, for PBDTT-SF-TT, a very low energy loss of 0.59 eV is pronounced, leading to the promisingly high voltage, and furthermore performance study and morphological results declare an additivefree PSC from PBDTT-SF-TT, which is beneficial to practical applications. Polymer Solar Cells

Recent advances of polymer acceptors for high-performance organic solar cells

Abstract: In the past few decades, polymer solar cells (PSCs) have been intensively investigated in academic fields. The study of non-fullerene polymer acceptors has become a hot research focus due to their excellent opto-electronic properties such as wide light-absorbing ability, appropriate molecular energy levels, and easy chemical modifications. The much higher power conversion efficiencies (PCEs) of non-fullerene PSCs relative to fullerene PSCs revealed the significant potential of non-fullerene acceptors in PSCs. This review systematically summarizes the recent advancements of efficient polymer acceptors, including perylene diimide-based, naphthalene diimide-based, diketopyrrolopyrrole-based, double B←N bridged bipyridyl-based, and other polymer acceptors. Their structure–property relationships were thoroughly analyzed and summarized, which may provide new guidance for the rational structural design of high-performance photovoltaic materials.

Classification, Synthesis, and Application of Luminescent Silica Nanoparticles: a Review.

Abstract: Luminescent materials are of worldwide interest because of their unique optical properties. Silica, which is transparent to light, is an ideal matrix for luminescent materials. Luminescent silica nanoparticles (LSNs) have broad applications because of their enhanced chemical and thermal stability. Silica spheres of various sizes could be synthesized by different methods to satisfy specific requirements. Diverse luminescent dyes have potential for different applications. Subject to many factors such as quenchers, their performance was not quite satisfying. This review thus discusses the development of LSNs including their classification, synthesis, and application. It is the highlight that how silica improves the properties of luminescent dye and what role silica plays in the system. Further, their applications in biology, display, and sensors are also described.

Molecular Design of Benzodithiophene-Based Organic Photovoltaic Materials.

Abstract: Advances in the design and application of highly efficient conjugated polymers and small molecules over the past years have enabled the rapid progress in the development of organic photovoltaic (OPV) technology as a promising alternative to conventional solar cells. Among the numerous OPV materials, benzodithiophene (BDT)-based polymers and small molecules have come to the fore in achieving outstanding power conversion efficiency (PCE) and breaking 10% efficiency barrier in the single junction OPV devices. Remarkably, the OPV device featured by BDT-based polymer has recently demonstrated an impressive PCE of 11.21%, indicating the great potential of this class of materials in commercial photovoltaic applications. In this review, we offered an overview of the organic photovoltaic materials based on BDT from the aspects of backbones, functional groups, alkyl chains, and device performance, trying to provide a guideline about the structure-performance relationship. We believe more exciting BDT-based photovol...

Toward Perovskite Solar Cell Commercialization: A Perspective and Research Roadmap Based on Interfacial Engineering.

Abstract: High-efficiency and low-cost perovskite solar cells (PVKSCs) are an ideal candidate for addressing the scalability challenge of solar-based renewable energy. The dynamically evolving research field of PVKSCs has made immense progress in solving inherent challenges and capitalizing on their unique structure-property-processing-performance traits. This review offers a unique outlook on the paths toward commercialization of PVKSCs from the interfacial engineering perspective, relevant to both specialists and nonspecialists in the field through a brief introduction of the background of the field, current state-of-the-art evolution, and future research prospects. The multifaceted role of interfaces in facilitating PVKSC development is explained. Beneficial impacts of diverse charge-transporting materials and interfacial modifications are summarized. In addition, the role of interfaces in improving efficiency and stability for all emerging areas of PVKSC design are also evaluated. The authors' integral contributions in this area are highlighted on all fronts. Finally, future research opportunities for interfacial material development and applications along with scalability-durability-sustainability considerations pivotal for facilitating laboratory to industry translation are presented.

The Curious Case of Fluorination of Conjugated Polymers for Solar Cells.

Abstract: ConspectusOrganic solar cells (OSCs) have been a rising star in the field of renewable energy since the introduction of the bulk heterojunction (BHJ) in 1992. Recent advances have pushed the efficiencies of OSCs to over 13%, an impressive accomplishment via collaborative efforts in rational materials design and synthesis, careful device engineering, and fundamental understanding of device physics. Throughout these endeavors, several design principles for the conjugated donor polymers used in such solar cells have emerged, including optimizing the conjugated backbone with judicious selection of building blocks, side-chain engineering, and substituents. Among all of the substituents, fluorine is probably the most popular one; improved device characteristics with fluorination have frequently been reported for a wide range of conjugated polymers, in particular, donor–acceptor (D–A)-type polymers. Herein we examine the effect of fluorination on the device performance of solar cells as a function of the positio...