Search

Considering the robust and stable nature of the active layers, advancing the power conversion efficiency (PCE) has long been the priority for all-polymer solar cells (all-PSCs). Despite the recent surge of PCE, the photovoltaic parameters of the state-of-the-art all-PSC still lag those of the polymer:small molecule-based devices. To compete with the counterparts, judicious modulation of the morphology and thus the device electrical properties are needed. It is difficult to improve all the parameters concurrently for the all-PSCs with advanced efficiency, and one increase is typically accompanied by the drop of the other(s). In this work, with the aids of the solvent additive (1-chloronaphthalene) and the n-type polymer additive (N2200), we can fine-tune the morphology of the active layer and demonstrate a 16.04% efficient all-PSC based on the PM6:PY-IT active layer. The grazing incidence wide-angle X-ray scattering measurements show that the shape of the crystallites can be altered, and the reshaped crystallites lead to enhanced and more balanced charge transport, reduced recombination, and suppressed energy loss, which lead to concurrently improved and device efficiency and stability. Funding Agencies|National Key Research and Development Program of China [2019YFA0705900]; Basic and Applied Basic Research Major Program of Guangdong Province [2019B030302007]; Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials [2019B121205002]; Shen Zhen Technology and Innovation Commission [JCYJ20170413173814007, JCYJ20170818113905024]; Hong Kong Research Grants CouncilHong Kong Research Grants Council [R602118]; collaborative research fund [C6023-19G, 16309218, 16310019, 16303917]; Hong Kong Innovation and Technology Commission [ITC-CNERC14SC01, ITS/471/18]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [21927811, 91433202, 22005121]; Swedish Research Council VRSwedish Research Council [2016-06146]; Swedish Research CouncilSwedish Research CouncilEuropean Commission; Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation [2017.0186, 2016.0059]; Hong Kong PhD Fellowship Scheme [PF17-03929]; Natural Science Foundation of Top Talent of SZTU [20200205]; China Postdoctoral Science FoundationChina Postdoctoral Science Foundation [2020M673054]; Postdoctoral Fund of Jinan University

Zhenghui Luo,1,* Jie Liu,1,* Hai Lin,2 Xi Ren,1 Hao Tian,1 Yi Liang,1 Weiyi Wang,1 Yuan Wang,1 Meifang Yin,1 Yuesheng Huang,1 Jiaping Zhang1 1Department of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University (Army Medical University), Chongqing 400038, People’s Republic of China; 2Engineering Research Center in Biomaterials, Sichuan University, Chengdu 610065, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jiaping ZhangDepartment of Plastic Surgery, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, The Third Military Medical University (Army Medical University), Chongqing 400038, People’s Republic of ChinaTel +86 23-68754353Email japzhang@aliyun.comBackground: Developing an ideal wound dressing that meets the multiple demands of safe and practical, good biocompatibility, superior mechanical property and excellent antibacterial activity is highly desirable for wound healing. Bacterial cellulose (BC) is one of such promising class of biopolymers since it can control wound exudates and can provide moist environment to a wound resulting in better wound healing. However, the lack of antibacterial activity has limited its application.Methods and Results: We prepared a flexible dressing based on a bacterial cellulose membrane and then modified it by chemical crosslinking to prepare in situ synthesis of nZnO/BCM via a facile and eco-friendly approach. Scanning electron microscopy (SEM) results indicated that nZnO/BCM membranes were characterized by an ideal porous structure (pore size: 30∼ 90 μm), forming a unique string-beaded morphology. The average water vapor transmission of nZnO/BCM was 2856.60 g/m2/day, which improved the moist environment of nZnO/BCM. ATR-FITR further confirmed the stepwise deposition of nano-zinc oxide. Tensile testing indicated that our nanocomposites were flexible, comfortable and resilient. Bacterial suspension assay and plate counting methods demonstrated that 5wt. % nZnO/BCM possessed excellent antibacterial activity against S.aureus and E. coli, while MTT assay demonstrated that they had no measurable cytotoxicity toward mammalian cells. Moreover, skin irritation test and histocompatibility examination supported that 5wt. % nZnO/BCM had no stimulation to skin and had acceptable biocompatibility with little infiltration of the inflammatory cells. Finally, by using a bacteria-infected (S. aureus and E. coli) murine wound model, we found that nZnO/BCM could prevent in vivo bacterial infections and promote wound healing via accelerating the re-epithelialization and wound contraction, and these membranes had no obvious toxicity toward normal tissues.Conclusion: Therefore, the constructed nZnO/BCM has great potential for biomedical applications as an efficient antibacterial wound dressing.Keywords: bacterial cellulose, nano-zinc oxide, in situ synthesis, antibacterial, non-toxicity, wound dressing

PSCs based on PBDB-T:MeIC1 achieved a larger Voc and Jsc and thus boosted the PCE compared to PBDB-T:MeIC-based PSCs., Isomers with small structural changes usually exhibit different properties. Rationally designing isomers of some high-performance SMAs can further enhance their function. In this work, an asymmetrical small molecule acceptor (SMA) MeIC1 isomerized from MeIC is reported. Compared with the symmetrical MeIC, the asymmetrical isomer showed almost the same absorption range but an elevated LUMO energy level and simultaneously enhanced π–π stacking and electron mobility by replacing the thieno[3,2-b]thiophene unit with a larger sized dithieno[3,2-b:2′,3′-d]thiophene unit in the ladder-type core of MeIC. As a result, the MeIC1-based PSCs achieved a higher PCE up to 12.58% with a promoted Voc and Jsc and an unchanged FF compared with those of MeIC-based PSCs when blended with PBDB-T. This work reveals that asymmetrical isomerization is effective for PCE promotion.