羅元

Inorganic 2D membranes are promising candidates for energy harvesting, water desalination, and ion sieving applications. Ion-transport control in nanofluidics is key to membrane performance. Fundamental ion-transport control based on the force–flux relationship is discussed for potential membrane designs, considering both electrostatic and structural contributions to the flux.

Abstract

Inorganic 2D materials offer a new approach to controlling mass diffusion at the nanoscale. Controlling ion transport in nanofluidics is key to energy conversion, energy storage, water purification, and numerous other applications wherein persistent challenges for efficient separation must be addressed. The recent development of 2D membranes in the emerging field of energy harvesting, water desalination, and proton/Li-ion production in the context of green energy and environmental technology is herein discussed. The fundamental mechanisms, 2D membrane fabrication, and challenges toward practical applications are highlighted. Finally, the fundamental issues of thermodynamics and kinetics are outlined along with potential membrane designs that must be resolved to bridge the gap between lab-scale experiments and production levels.

In situ resonance Raman spectroscopy was used for noninvasive and nondestructive microscopic investigations of dynamic interface evolutions in dye‐sensitized solar cells under operando conditions. The creation of new species was observed, and interactions between charge separation pathways and molecular vibrations were studied, providing new insight for the optimization of dye‐sensitized solar cells.

Abstract

Interfaces play an important role in enhancing the energy conversion performance of dye‐sensitized solar cells (DSCs). The interface effects have been studied by many techniques, but most of the studies only focused on one part of a DSC, rather than on a complete solar cell. Hence, monitoring the interface evolution of a DSC is still very challenging. Here, in situ/operando resonance Raman (RR) spectroscopic analyses were carried out to monitor the dynamics of the photovoltaic conversion processes in a DSC. We observed the creation of new species (i.e., polyiodide and iodine aggregates) in the photosensitization process. We also obtained molecular‐scale dynamic evidence that the bands from the C=C and C=N bonds of 2,2′‐bipyridyl (bpy), the S=C=N bonds of the NCS ligand, and photochemical products undergo reasonably strong intensity and frequency changes, which clearly demonstrates that they are involved in charge separation. Furthermore, RR spectroscopy can also be used to quickly evaluate the performance of DSCs.

Publication date: March 2020

Source: Solar Energy Materials and Solar Cells, Volume 206

Author(s): X.F. Zhao, A. Aierken, M. Heini, M. Tan, Y.Y. Wu, S.L. Lu, R.T. Hao, J.H. Mo, Y. Zhuang, X.B. Shen, Y. Xu, Q.Q. Lei, Q. Guo

Abstract

Publication date: Available online 25 November 2019

Source: Solar Energy Materials and Solar Cells

Author(s): Wenjie Wang, Jian He, Di Yan, Chris Samundsett, Sieu Pheng Phang, Zengguang Huang, Wenzhong Shen, James Bullock, Yimao Wan

Publication date: February 2020

Source: Solar Energy Materials and Solar Cells, Volume 205

Author(s): Ewa Klugmann-Radziemska, Anna Kuczyńska-Łażewska

Publication date: January 2019

Source: Organic Electronics, Volume 64

Author(s): Dong Zhao, Jiawei Zheng, Zheng Gong, Jian Wu, Jianxin Tang, Qing Zhang

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Publication date: June 2018
Source:Organic Electronics, Volume 57
Author(s): Tinghai Yan, Haijun Bin, Chenkai Sun, Zhi-Guo Zhang, Yongfang Li
We designed and synthesized two new donor-acceptor (D-A) copolymers J46 and J47 through replacing thiophene conjugated side chains by thieno[3,2-b]thiophene (TT) in the benzo[1,2-b:4,5-b’]dithiophene (BDT) units copolymerized with fluorobenzotriazole (FBTA). J46 possesses alkyl substituent on the TT conjugated side chains and J47 with alkylsilyl substituent on the TT side chains. Power conversion efficiency (PCE) of the polymer solar cells (PSCs) based on J47 as donor and an n-type organic semiconductor (n-OS) ITIC as acceptor with thermal annealing at 150 °C for 2 min and with DIO additive treatment reached 9.0%, while the PCE of the J46-based PSCs was only 2.33%. The results indicate that the size and nature of the conjugated side chains in the J-series BDT-alt-FBTA copolymers influence the physicochemical and photovoltaic properties of the 2D-conjugated polymers significantly, and the side chain engineering could play an important role in improving the photovoltaic performance of the 2D-conjugated polymer donor materials.

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Publication date: 8 September 2017
Source:Polymer, Volume 125
Author(s): Guangrun Liu, Chao Weng, Pan Yin, Songting Tan, Ping Shen
Three low bandgap conjugated copolymers (PB-DPP, PDFB-DPP, and PTFB-DPP) based on 1,4-dithienylphenylene and diketopyrrolopyrrole units were synthesized and characterized as the donor materials for polymer solar cells. The effect of the number of fluorine atoms on thermodynamic, crystalline, physicochemical and photovoltaic properties of the copolymers was comparatively investigated. Results indicate that the absorption peaks of polymer solutions are blue-shifted and optical bandgaps are gradually decreased along with the increase of the number of fluorine atoms. Moreover, PDFB-DPP and PTFB-DPP show better light-harvesting abilities, higher crystallinities and lower-lying HOMO energy levels than those of PB-DPP. Photovoltaic performances of these copolymers were studied and optimized. PDFB-DPP and PTFB-DPP deliver a power conversion efficiency of 5.31% and 4.93%, respectively, both of which are higher than that of PB-DPP (4.13%) due to the increased J sc and V oc. This work demonstrates that the number of fluorine substitution is crucial to improving optoelectronic properties.

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Publication date: September 2017
Source:Dyes and Pigments, Volume 144
Author(s): Maria Grishina, Oleg Bol'shakov, Andrey Potemkin, Vladimir Potemkin
Important aspects of dye-sensitized solar cells (DSSCs) fabrication based on dyes including benzothiadiazole unit were investigated. Two absorption peaks of the dyes covering the 330–551 nm region and possessing moderate band energy gap (1.83–2.16 eV) were found to be important to demonstrate high photovoltaic efficiency (η > 8) in metal free iodide/iodine electrolyte composed DSSCs. Furthermore, the dye energy band gap determined from optical spectra decreases with the increase of DSSCs short circuit photocurrent density, which in turn linearly increases the photovoltaic efficiency of DSSCs. While the RedOx potentials of dyes are less functionally related to the photovoltaic properties of the DSSCs, their appropriate values (0.67 ≤ E ox  ≤ 1.1 V and −1.75 ≤ E red  ≤ −0.91 V) can be important for efficient DSSCs. Fabrication details increasing photovoltaic efficiency of the devices based on dyes with benzothiadiazole unit were found. The relationships obtained in the work can be used for preliminary prognosis whether a newly synthesized dye is a promising metal-free sensitizer for DSSCs or not.

Publication date: May 2016
Source:Organic Electronics, Volume 32
Author(s): Wallace W.H. Wong, Sam Rudd, Kola Ostrikov, Melanie Ramiasa-MacGregor, Jegadesan Subbiah, Krasimir Vasilev
The use of plasma deposited organic thin films as the interlayer component in organic solar cells applications is demonstrated for the first time. Up to 20% increase in solar cell device performance was observed when an interlayer deposited from the vapour of 4-methylthiazole was used. This work demonstrates the potential of plasma deposition of organic films to be integrated in fabrication of organic solar cells with superior properties.

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