標題: Distribution of Crystalline Polymer and Fullerene Clusters in Both Horizontal and Vertical Directions of High-Efficiency Bulk Heterojunction Solar Cells
作者: Liu, Chih-Ming
Su, Ming-Shin
Jiang, Jian-Ming
Su, Yu-Wei
Su, Chun-Jen
Chen, Charn-Ying
Tsao, Cheng-Si
Wei, Kung-Hwa
材料科學與工程學系
Department of Materials Science and Engineering
關鍵字: bulk heterojunction solar cells;morphology;fullerenes;polymer crystallinity;grazing-incidence X-ray scattering;transmission electron microscopy
公開日期: 26-六月-2013
摘要: In this study, we used (i) synchrotron grazing-incidence small-/wide-angle X-ray scattering to elucidate the crystallinity of the polymer PBTC12TPD and the sizes of the clusters of the fullerenes PC61BM and ThC61BM and (ii) transmission electron microscopy/electron energy loss spectroscopy to decipher both horizontal and vertical distributions of fullerenes in PBTC12TPD/fullerene films processed with chloroform, chlorobenzene and dichlorobezene. We found that the crystallinity of the polymer and the sizes along with the distributions of the fullerene clusters were critically dependent on the solubility of the polymer in the processing solvent when the solubility of fullerenes is much higher than that of the polymer in the solvent. In particular, with chloroform (CF) as the processing solvent, the polymer and fullerene units in the PBTC12TPD/ThC61BM layer not only give rise to higher crystallinity and a more uniform and finer fullerene cluster dispersion but also formed nanometer scale interpenetrating network structures and presented a gradient in the distribution of the fullerene clusters and polymer, with a higher polymer density near the anode and a higher fullerene density near the cathode. As a result of combined contributions from the enhanced polymer crystallinity, finer and more uniform fullerene dispersion and gradient distributions, both the short current density and the fill factor for the device incorporating the CF-processed active layer increase substantially over that of the device incorporating a dichlorobenzene-processed active layer; the resulting power conversion efficiency of the device incorporating the CF-processed active layer was enhanced by 46% relative to that of the device incorporating a dichlorobenzene-processed active layer.
URI: http://dx.doi.org/10.1021/am4011995
http://hdl.handle.net/11536/22276
ISSN: 1944-8244
DOI: 10.1021/am4011995
期刊: ACS APPLIED MATERIALS & INTERFACES
Volume: 5
Issue: 12
起始頁: 5413
結束頁: 5422
顯示於類別:期刊論文


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