| 1. |
- Fan, Qunping, 1989, et al.
(författare)
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Over 14% efficiency all-polymer solar cells enabled by a low bandgap polymer acceptor with low energy loss and efficient charge separation
- 2020
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Ingår i: Energy & Environmental Science. - : Royal Society of Chemistry. - 1754-5692 .- 1754-5706. ; 13:12, s. 5017-5027
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Tidskriftsartikel (refereegranskat)abstract
- Obtaining both high open-circuit voltage (V-oc) and short-circuit current density (J(sc)) has been a major challenge for efficient all-polymer solar cells (all-PSCs). Herein, we developed a polymer acceptor PF5-Y5 with excellent optical absorption capability (onset extending to similar to 880 nm and maximum absorption coefficient exceeding 105 cm(-1) in a film), high electron mobility (3.18 x 10(3) cm(2) V-1 s(-1)) and high LUMO level (-3.84 eV) to address such a challenge. As a result, the PBDB-T:PF5-Y5-based all-PSCs achieved a high power conversion efficiency of up to 14.45% with both a high Voc (0.946 V) and a high Jsc (20.65 mA cm(-2)), due to the high and broad absorption coverage, small energy loss (0.57 eV) and efficient charge separation and transport in the device, which are among the best values in the all-PSC field. In addition, the all-PSC shows a similar to 15% improvement in PCE compared to its counterpart small molecule acceptor (Y5)-based device. Our results suggest that PF5-Y5 is a very promising polymer acceptor candidate for applications in efficient all-PSCs.
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| 2. |
- Liu, Yanfeng, et al.
(författare)
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In Situ Optical Studies on Morphology Formation in Organic Photovoltaic Blends
- 2021
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Ingår i: Small Methods. - : John Wiley & Sons. - 2366-9608. ; 5:10, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- The efficiency of bulk heterojunction (BHJ) based organic solar cells is highly dependent on the morphology of the blend film, which is a result of a fine interplay between donor, acceptor, and solvent during the film drying. In this work, a versatile set-up of in situ spectroscopies is used to follow the morphology evolution during blade coating of three iconic BHJ systems, including polymer:fullerene, polymer:nonfullerene small molecule, and polymer:polymer. the drying and photoluminescence quenching dynamics are systematically study during the film formation of both pristine and BHJ films, which indicate that the component with higher molecular weight dominates the blend film formation and the final morphology. Furthermore, Time-resolved photoluminescence, which is employed for the first time as an in situ method for such drying studies, allows to quantitatively determine the extent of dynamic and static quenching, as well as the relative change of quantum yield during film formation. This work contributes to a fundamental understanding of microstructure formation during the processing of different blend films. The presented setup is considered to be an important tool for the future development of blend inks for solution-cast organic or hybrid electronics.
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| 3. |
- Karunanayake, Amila, et al.
(författare)
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Experiences on Mobile-ATM Deployment in a Developing Country
- 2008
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Ingår i: Proceedings of The 1st International Conference on M4D Mobile Communication Technology for Development (M4D 2008, General Tracks). - Karlstad : Karlstad University. - 9789170632211 ; , s. 108-116
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Konferensbidrag (refereegranskat)
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| 4. |
- Wang, Yuming, et al.
(författare)
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Light-induced degradation of fullerenes in organic solar cells : a case study on TQ1:PC71BM
- 2018
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 6:25, s. 11884-11889
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Tidskriftsartikel (refereegranskat)abstract
- The stability of organic solar cells (OSCs) is critical for practical applications of this emerging technology. Unfortunately, in spite of intensive investigations, the degradation mechanisms in OSCs have not been clearly understood yet. In this report, we employ a range of spectroscopic and transport measurements, coupled with drift-diffusion modelling, to investigate the light-induced degradation mechanisms of fullerene-based OSCs. We find that trap states formed in the fullerene phase under illumination play a critical role in the degradation of the open-circuit voltage (V-OC) in OSCs. Our results indicate that the degradation is intrinsic to the fullerenes in OSCs and that alternative acceptor materials are desired for the development of stable OSCs.
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| 5. |
- Zhang, Chao, et al.
(författare)
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2023 Roadmap on molecular modelling of electrochemical energy materials
- 2023
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Ingår i: Journal of Physics. - : Institute of Physics Publishing (IOPP). - 2515-7655. ; 5:4
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Tidskriftsartikel (refereegranskat)abstract
- New materials for electrochemical energy storage and conversion are the key to the electrification and sustainable development of our modern societies. Molecular modelling based on the principles of quantum mechanics and statistical mechanics as well as empowered by machine learning techniques can help us to understand, control and design electrochemical energy materials at atomistic precision. Therefore, this roadmap, which is a collection of authoritative opinions, serves as a gateway for both the experts and the beginners to have a quick overview of the current status and corresponding challenges in molecular modelling of electrochemical energy materials for batteries, supercapacitors, CO2 reduction reaction, and fuel cell applications.
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| 6. |
- Zhang, Ge, et al.
(författare)
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SIMPA: A SIP-based Mobile Payment Architecture
- 2008
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Konferensbidrag (refereegranskat)abstract
- In recent years, many mobile payment (MP) schemes have been proposed and used in practise. However, a prerequisite for extended acceptance and adoption of MP technologies is to deploy an effective MP system. So far, there is no such a standardised and scalable MP platform. Most current MP schemes are circumscribed by its mobile network infrastructures. Fortunately, the fast advancement of 3G technology equips next generation mobile phone network more benefits. Following this direction, we propose SIMPA - A SIP-based Mobile Payment Architecture for next generation mobile network, which not only supports P2P payment communications between customers and merchants using Session Initiation Protocol (SIP), but also supports several traditional Internet security protocols, to enhance privacy, confidentiality and integrity during the transaction. This paper depicts detailed protocol and system architecture of SIMPA. Some application examples from customers' view are shown to demonstrate its function and feature
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| 7. |
- Zhang, Ge, et al.
(författare)
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Towards Secure Mobile Payment Based on SIP
- 2008
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Konferensbidrag (refereegranskat)abstract
- Mobile payment has some unique advantages over more traditional payment methods in, for example, TV shopping and mobile multimedia services. Unfortunately, most existing mobile payment solutions rely heavily on underlying communication infrastructures, which are platform-dependent and have no unified implementation criteria. This limitation is reducing, however, through the rapid spread of the Voice over IP (VoIP) telephony service and its integration with mobile phones. The Session Initiation Protocol (SIP) is currently the standard signalling protocol of VoIP. Mobile payment is expected to be implemented and deployed in an SIP environment in order to keep pace with the evolution of the mobile phone network. The goal of this paper is firstly to propose a new mobile payment scheme based on SIP. The protocol of the proposed framework is thoroughly analysed. Secondly, we evaluate security issues and propose enhanced solutions to make this new framework applicable in practise
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