| 1. |
- Shao, Shuyan, et al.
(författare)
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Enhanced Performance of Inverted Polymer Solar Cells by Using Poly(ethylene oxide)-Modified ZnO as an Electron Transport Layer
- 2013
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society. - 1944-8244 .- 1944-8252. ; 5:2, s. 380-385
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we report enhanced performance of inverted polymer solar cells composed of poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl] (TQ1):[6,6]-phenyl-C-71-butyric acid methyl ester (PC71BM) blends by using poly(ethylene oxide) (PEO)-modified ZnO as an electron transport layer. It is found that PEO modification to the ZnO nanoparticle surface can effectively passivate the surface traps of ZnO, suppress the recombination loss of carriers, reduce the series resistance, and improve the electrical coupling of ZnO/active layer. Consequently, both the short-circuit current (J(SC)) and the fill factor (FF) of the inverted solar cells are considerably improved. The resulting power conversion efficiency (PCE) is improved to 5.64% as compared to 4.5% of the reference device using a ZnO electron transport layer. Moreover, this approach can also successfully improve the J(SC) and FF of anther inverted solar cell composed of poly[N-9 -hepta-decanyl-2,7-carbazole-alt-5,5-(4,7-dithienyl-2,1,3-benzothiadiazole)] (PCDTBT):PC71BM blends. The PCE of the device based on the PEO-modified ZnO layer is increased to 6.59% from 5.39% of the reference device based on the ZnO layer.
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| 2. |
- Shao, Shuyan, et al.
(författare)
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Optimizing ZnO nanoparticle surface for bulk heterojunction hybrid solar cells
- 2013
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Ingår i: Solar Energy Materials and Solar Cells. - : Elsevier. - 0927-0248 .- 1879-3398. ; 118, s. 43-47
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Tidskriftsartikel (refereegranskat)abstract
- The performance of hybrid solar cells composed of polymer and ZnO is mainly hindered by the defects of ZnO. Here, we investigate the effects of ZnO nanoparticle surface modification with poly(ethylene oxide) (PEO) on the performance of bulk heterojunction hybrid solar cells based on poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) and ZnO nanoparticles. The reference device using ZnO nanoparticles as electron acceptor shows an open-circuit voltage (VOC) of 0.83 V, a short-circuit current (JSC) of 3.00 mA/cm2, a fill factor (FF) of 0.46 and a power conversion efficiency (PCE) of 1.15%. After modification with very small amount of PEO, the PCE will be enhanced, which is attributed to less surface traps of ZnO nanoparticles with PEO modification. With optimized PEO (0.05%) modified ZnO nanoparticles as electron acceptors, the device typically shows a VOC of 0.86 V, a JSC of 3.84 mA/cm2, a FF of 0.51 and a PCE of 1.68% due to less recombination loss of carriers, smaller series resistance, and improved electrical coupling between ZnO nanoparticle and MEH-PPV. However, further increase of PEO content to 0.3% will deteriorate device performance.
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| 3. |
- Zheng, Kaibo, et al.
(författare)
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Fast Monolayer Adsorption and Slow Energy Transfer in CdSe Quantum Dot Sensitized ZnO Nanowires
- 2013
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society. - 1089-5639 .- 1520-5215. ; 117:29, s. 5919-5925
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Tidskriftsartikel (refereegranskat)abstract
- A method for CdSe quantum dot (QD) sensitization of ZnO nanowires (NW) with fast adsorption rate is applied. Photoinduced excited state dynamics of the quantum dots in the case of more than monolayer coverage of the nanowires is studied. Transient absorption kinetics reveals an excitation depopulation process of indirectly attached quantum dots with a lifetime of similar to 4 ns. Photoluminescence and incident photon-to-electron conversion efficiency show that this process consists of both radiative e-h recombination and nonradiative excitation-to-charge conversion. We argue that the latter occurs via interdot energy transfer from the indirectly attached QDs to the dots with direct contact to the nanowires. From the latter, fast electron injection into ZnO occurs. The energy transfer time constant is found to be around 5 ns.
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