scispace - formally typeset
Search or ask a question
Author

Chunyan Yang

Bio: Chunyan Yang is an academic researcher from Lanzhou Jiaotong University. The author has contributed to research in topics: Materials science & Organic solar cell. The author has an hindex of 12, co-authored 37 publications receiving 427 citations.

Papers published on a yearly basis

Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, a self-doping polymer cathode interface material for organic solar cells was synthesized by incorporating benzotriazole (BTA) as an electron-deficient group and a fluorene containing an amino group.
Abstract: Self-doped polymer cathode interface materials for organic solar cells have been widely investigated to enhance the ohmic contact between the electrode and the photoactive layer. Herein, a novel polymer named PBTA-FN with self-doping effect was successfully synthesized by incorporating benzotriazole (BTA) as an electron-deficient group and a fluorene containing an amino group. In favor of the n-type backbone and amine-based groups, an obvious n-type doping was obtained, resulting in the dramatically improved conductivity of PBTA-FN. Subsequently, PBTA-FN and PFN as cathode interface layers (CILs) were successfully applied in the organic solar cells based on PBDB-T-2F:IT-4F. A notable power conversion efficiency of 12.18% and 11.03% could be achieved with PBTA-FN and PFN as CILs, respectively. PBTA-FN showed better planarity than PFN as observed from the results obtained via density functional theory. The self-doping behaviour of PBTA-FN was determined by electron paramagnetic resonance, which exhibited a higher mobility and carrier density. The water contact angle results on the surface of the active-layer/PBTA-FN bilayer suggested that the PBTA-FN surface polarity was improved, which was attributed to the larger interface dipole. Thus, PBTA-FN can reduce the work function of an Al electrode and enhance the built-in electric potential, which were further confirmed by ultraviolet photoelectron spectroscopy and Mott Schottky curves, and the related device produced a higher Voc (0.88 V) than PFN (0.86 V). This work provides a deeper understanding of the PBTA-FN interlayer mechanism and has a potential application in optoelectronic devices.

80 citations

Journal ArticleDOI
TL;DR: In this paper, a non-toxic green food additive, benzyl salicylate (BS), was introduced as a novel solvent additive into inverted PSCs based on ITO/ZnO/PTB7-Th:PC71BM/MoO3/Ag.
Abstract: Solvent additives play an important role in optimizing the morphology of the photoactive layer and improving the photovoltaic performance of polymer solar cells (PSCs). However, the toxicity of common additives to the environment limits their further application in photovoltaic cells. Herein, a non-toxic green food additive, benzyl salicylate (BS), was introduced as a novel solvent additive into inverted PSCs based on ITO/ZnO/PTB7-Th:PC71BM/MoO3/Ag. Subsequently, the effect of BS on the photovoltaic performance was studied, and the best power conversion efficiency (PCE) of 9.43% was achieved when adding 2% BS into the photoactive layer of PSCs. Furthermore, the PSCs treated by 1–4% BS all exhibited good photovoltaic performance compared to that using 3% DIO (8.56%), which demonstrated that the universality was very strong. In addition, a good solubility for fullerenes was presented on BS like DIO, which was determined by atomic force microscopy and transmission electron microscopy. The water contact angle and time-off flight secondary ion mass spectroscopy results manifested that the good solubility of high-boiling-point additive BS to PC71BM could boost the phase composition distribution at the surface and in the vertical direction. Thus, an efficient route for exciton dissociation and charge transfer could be formed when the PSC was processed via 2% BS, which could also be ascertained by space charge limited current, impedance spectroscopy. The present research findings provide useful information for realizing large-area PSC fabrication, where a greener non-toxic additive is always preferred.

53 citations

Journal ArticleDOI
TL;DR: In this paper, double ETL formed by the introduction of l -Arginine ( l -Arg) provided an efficient, low-cost, green and healthy method for the preparation of high-performance OSCs.

45 citations

Journal ArticleDOI
14 Jul 2017-Polymer
TL;DR: In this paper, two donor-π-acceptor (Dπ-A) type low bandgap (LBG) conjugated polymers, namely, PT-DTNT-DT and PTT-DT NT-DT, consisting of thiophene (T) and/or thieno[3,2- b ]thiophene(TT) as donor moiety, two flanking 2decyltetradecylthienyl as π-bridges and strong electron-withdrawing naphtho[1,2]-bis[

38 citations

Journal ArticleDOI
TL;DR: In this article , a ternary strategy of halogen-free solvent processing can open up a promising pathway for the preparation of polymer solar cells on a large scale and can effectively improve the power conversion efficiency with an appropriate third component.
Abstract: A ternary strategy of halogen-free solvent processing can open up a promising pathway for the preparation of polymer solar cells (PSCs) on a large scale and can effectively improve the power conversion efficiency with an appropriate third component. Herein, the green solvent o-xylene (o-XY) is used as the main solvent, and the non-fullerene acceptor Y6-DT-4F as the third component is introduced into the PBB-F:IT-4F binary system to broaden the spectral absorption and optimize the morphology to achieve efficient PSCs. The third component, Y6-DT-4F, is compatible with IT-4F and can form an "alloy acceptor", which can synergistically optimize the photon capture, carrier transport, and collection capabilities of the ternary device. Meanwhile, Y6-DT-4F has strong crystallinity, so when introduced into the binary system as the third component can enhance the crystallization, which is conducive to the charge transport. Consequently, the optimal ternary system based on PBB-F:IT-4F:Y6-DT-4F achieved an efficiency of 15.24%, which is higher than that of the binary device based on PBB-F:IT-4F (13.39%).

37 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: This review 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.
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...

942 citations

Journal ArticleDOI
TL;DR: In this paper, the power conversion efficiency (PCE) of single-junction polymer solar cells (PSCs) has made a remarkable breakthrough recently, and the PM7:Y6 has achieved PCEs as high as 17.0% by the hot-cast method, due to the improved open-circuit voltage.
Abstract: Power conversion efficiency (PCE) of single-junction polymer solar cells (PSCs) has made a remarkable breakthrough recently. Plenty of work was reported to achieve PCEs higher than 16% derived from the PM6:Y6 binary system. To further increase the PCEs of binary OSCs incorporating small molecular acceptor (SMA) Y6, we substituted PM6 with PM7 due to the deeper highest occupied molecular orbital (HOMO) of PM7. Consequently, the PM7:Y6 has achieved PCEs as high as 17.0% by the hot-cast method, due to the improved open-circuit voltage ( V OC). Compared with PM6, the lower HOMO of PM7 increases the gap between E LUMO-donor and E HOMO-acceptor, which is proportional to V OC. This research provides a high PCE for single-junction binary PSCs, which is meaningful for device fabrication related to PM7 and commercialization of PSCs.

275 citations

Journal ArticleDOI
TL;DR: In this article, organic, inorganic and hybrid materials are used as anode and cathode interlayers in conventional and inverted fullerene-free solar cells, respectively.
Abstract: Polymer solar cells based on fullerene acceptors have reached in recent years power conversion efficiencies (PCEs) approaching 13%. The advent of non-fullerene acceptors (NFAs) with the advantages of synthetic versatility, a strong absorption ability and high thermal stability has resulted in impressive PCEs of over 18% in single junction devices. The insertion of interlayers between the active components and electrodes plays a key role in charge collection, boosts the efficiency and improves the device stability. However, the mechanisms regulating the interaction between interlayer materials and active layers based on NFAs are not yet completely rationalized. This review article summarizes organic, inorganic and hybrid materials used as anode and cathode interlayers in conventional and inverted fullerene-free solar cells. Particular attention is paid to the distinctive features of the interlayers when used in non-fullerene solar cells. We will also comment on the fabrication processes with an emphasis on the transition from small area, lab devices to large area modules and on possible mechanisms which are behind.

126 citations

Journal ArticleDOI
TL;DR: In this article, the authors summarized the important advances of conjugated polymers developed recently for both high-performance fullerene and non-fullerene-based PSCs, including both p-type and n-type polymers.

124 citations