| 1. |
- Jia, Yuehua, et al.
(författare)
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Efficient polymer bulk heterojunction solar cells with cesium acetate as the cathode interfacial layer
- 2013
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Ingår i: Renewable energy. - : Elsevier. - 0960-1481 .- 1879-0682. ; 50, s. 565-569
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Tidskriftsartikel (refereegranskat)abstract
- The enhanced performance of polymer solar cells based on regioregular poly(3-hexylthiophene) (P3HT) and methanofullerene [6,6]-phenyl C-61-butyric acid methyl ester (PCBM) blend was achieved by using cesium acetate (CH3COOCs) as cathode buffer layer. Under 100 mW/cm(2) white light illumination, the device with 0.8 nm thick CH3COOCs as cathode buffer layer exhibits power conversion efficiency (PCE) as high as (4.16 +/- 0.02) %. Compared to the control devices without cathode buffer layer and with LiF as cathode buffer layer, the PCE is enhanced similar to 100% and similar to 31%, respectively. The introduction of the CH3COOCs buffer layer effectively improves the photo-generated charge collection. The Kelvin Probe measurement shows that the work function of the CH3COOCs is estimated to be -4.0 eV, which has an ideal energy band match with PCBM and a good property for electron collection. The static contact angle results indicated that the CH3COOCs with the hydrophobic CH3COO- group has an improved wettability between the buffer layer and the hydrophobic organic active layer surface, resulting in better interfacial contact and reduced contact resistance. The improved performance may be attributed to the dissociation of semi-conducting CH3COOCs upon deposition to liberate Cs with a low work function, which reduces the interface resistance of the active layer and the cathode and enhances the interior electric field that may result in efficient charge transportation. Therefore, the CH3COOCs interlayer could be a promising alternative to LiF to improve the efficiency of the electron collection of polymer bulk heterojunction solar cells.
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| 2. |
- Ma, Chunyu, et al.
(författare)
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Plasmon-enhanced organic solar cells with solution-processed three-dimensional Ag nanosheets
- 2013
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Ingår i: Solar Energy Materials and Solar Cells. - : ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS. - 0927-0248 .- 1879-3398. ; 109, s. 227-232
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Tidskriftsartikel (refereegranskat)abstract
- The silver nanosheets (AgNSs) prepared via normal silver mirror reaction were used to improve the performance of organic solar cells. AgNSs with a size of about 100 nm in width and 10 nm in thickness formed a 3-D network on an indium tin oxide (ITO) surface. Organic solar cells with a structure of ITO/AgNSs/poly(3,4-ethylene dioxythiophene) poly(styrenesulfonate) (PEDOT:PSS)/poly(3-hexylthiophene) and [6,6]-phenyl C-61 butyric acid methyl ester (P3HT:PC61BM)/LiF/Al exhibited an open circuit voltage (V-oc) of 0.60 +/- 0.01 V, short circuit current density (J(sc)) of 11.16 +/- 0.08 mA/cm(2), a fill factor (FF) of 53.69 +/- 0.92%, and power conversion efficiency (PCE) of 3.60 +/- 0.06%. The PCEs of organic solar cells with 3-D AgNSs layers were 1.29 times that of the control device without 3-D AgNSs layer. We attributed the improvement of the efficiency to localized surface plasmon resonance (LSPR) induced by the 3-D network of AgNSs, which enhanced the light harvest of active layers, increased the probability of exciton generation and dissociation.
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| 3. |
- Qin, Wenjing, et al.
(författare)
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Surface states of ZnO nanoparticles effect on the performance of inverted-organic solar cells
- 2013
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Ingår i: Journal of Renewable and Sustainable Energy. - : American Institute of Physics (AIP). - 1941-7012. ; 5:5
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Tidskriftsartikel (refereegranskat)abstract
- ZnO is a promising material used as the electron transport layer in the inverted organic solar cells (IOSCs). However, the electrical or photoelectric properties of ZnO nanoparticles are governed by the surface states of the nanoparticles. Here, we demonstrate that the large number of hydroxyl (-OH) existed on the ZnO nanoparticles films have a vast impact on the performance of IOSCs with the structure of ITO/ZnO/poly(3-hexylthiophene) (P3HT):[6,6]-phenyl C-61 butyric acid methyl ester (PCBM)/MoO3/Ag. The surface hydroxyl groups depredate active layer via elevating photocatalytic activity of the ZnO, hence deteriorate the device performance. Experimental results show that hydroxyl groups can be effectively detached from ZnO film by annealing. Hydroxyl groups detach more with increasing annealing temperature, resulting in less degradation of the active layer. Therefore, the efficiency is significantly improved due to increased photo-current density and decreased series resistance of IOSCs. The best device exhibits a power conversion efficiency of 3.05% after annealing at 150 degrees C.
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| 4. |
- Wang, Yaling, et al.
(författare)
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Enhanced performance and stability in polymer photovoltaic cells using lithium benzoate as cathode interfacial layer
- 2011
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Ingår i: SOLAR ENERGY MATERIALS AND SOLAR CELLS. - : Elsevier Science B.V., Amsterdam.. - 0927-0248. ; 95:4, s. 1243-1247
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Tidskriftsartikel (refereegranskat)abstract
- We report the enhanced performance and stability of polymer solar cells based on regioregular poly(3-hexylthiophene)(P3HT) and methanofullerene [6,6]-phenyl C-61-butyric acid methyl ester (PCBM) blend using lithium benzoate (C6H5COOLi) as cathode buffer layer between the active layer and the Al cathode. The effects of the C6H5COOLi thickness on the performance of polymer solar cell are also investigated. Under 100 mW/cm(2) white light illumination, the device with 1 nm thick C6H5COOLi as cathode buffer layer exhibits power conversion efficiency (PCE) as high as 3.41 +/- 0.07% and the device stability is greatly extended. Compared to the solar cell with LiF/AI cathode, the PCE is increased ca. 9.4%. Introduction of C6H5COOLi buffer layer effectively increases the shunt resistance and improves the photo-generated charge collection. The improved performance may attribute to the dissociation of semi-conducting C6H5COOLi upon deposition to liberate Li with a low work function, which reduces the interface resistance of the active layer and the cathode and enhances the interior electric field that may result in efficient charge transportion. In addition, the C6H5COOLi layer may serve as an effective oxygen and moisture diffusion barrier for the organic solar cells. Therefore. C6H5COOLi is a promising candidate as an interlayer to improve the efficiency of electron collection and to reduce the ambience influence on the stability of polymer solar cells.
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| 5. |
- Yang, Liying, et al.
(författare)
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Effect of cathode buffer layer on the stability of polymer bulk heterojunction solar cells
- 2010
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Ingår i: SOLAR ENERGY MATERIALS AND SOLAR CELLS. - : Elsevier Science B.V., Amsterdam.. - 0927-0248. ; 94:10, s. 1831-1834
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Tidskriftsartikel (refereegranskat)abstract
- The effect of cathode buffer layer on the stability of polymer solar cells with cesium carbonate (Cs2CO3) as the cathode buffer layer was investigated. Compared with traditional devices using lithium fluoride (LiF) as buffer layer, the use of the Cs2CO3 layer has enhanced not only open-circuit voltages and power conversion efficiencies of the polymer solar cells due to better contact with the cathode but also the device stability. From results of stability test, we concluded that the inserted Cs2CO3 buffer layer is working as a better shielding and scavenging protector which prevents the intruding of oxygen and humidity into the active layer, thereby improving the lifetime of unpackaged devices.
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| 6. |
- Yin, Bin, et al.
(författare)
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Solution-processed bulk heterojunction organic solar cells based on an oligothiophene derivative
- 2010
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Ingår i: Applied Physics Letters. - : American Institute of Physics. - 0003-6951 .- 1077-3118. ; 97:2, s. 023303-
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Tidskriftsartikel (refereegranskat)abstract
- Organic bulk heterojunction (BHJ) solar cells based on a dicyanovinyl-substituted oligothiophene as a donor and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) as an acceptor were fabricated and characterized. The oligothiophene derivative can absorb long wavelength photons of the solar radiation, which makes the solar cells with an optimized weight ratio of 1:1.4 have a decent short-circuit current density (12.4 mA/cm(2)) and open-circuit voltage (0.88 V) under AM 1.5G illumination with an intensity of 100 mW/cm(2). A power conversion efficiency (PCE) of 3.7% is achieved, which is among the best PCEs of solution processed small molecule BHJ solar cells.
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