標題: Ligands affect the crystal structure and photovoltaic performance of thin films of PbSe quantum dots
作者: Kuo, Chih-Yin
Su, Ming-Shin
Ku, Ching-Shun
Wang, Shu-Min
Lee, Hsin-Yi
Wei, Kung-Hwa
材料科學與工程學系
Department of Materials Science and Engineering
公開日期: 2011
摘要: We have prepared thin films of PbSe quantum dots (QDs) featuring three different ligands, oleic acid (OA), butylamine (BA), and 1,2-ethanedithiol (EDT), which have pronounced affects on the arrangement and photovoltaic performance of the PbSe QDs in the thin films. Transmission electron microscopy revealed that ligands that altered the inter-QD spacing induced significant changes in the packing of the PbSe QDs in localized regions of small areas (300 x 300 nm) of the thin films: from a superlattice of OA-capped PbSe QDs to a chaotic pattern of EDT-capped PbSe QDs. Using a synchrotron X-ray reflectivity probe and data fitting, we determined that the roughness decreased and the average densities increased for large-area (1.5 x 1.5 cm) PbSe QD thin films capped with BA and EDT, relative to those of the OA-capped PbSe QD film. In particular, the PbSe QDs' vertical packing density, which is critical for charge transport, increased substantially for the system incorporating EDT ligands. As a result, devices containing the EDT-treated PbSe QD film as the active layer displayed much improved power conversion efficiencies (PCEs) relative to those of corresponding devices featuring either the OA-or BA-capped PbSe QD films as active layers. Adopting a layer-by-layer technique, we fabricated a EDT-capped PbSe QD device that exhibited a PCE of 2.45%.
URI: http://hdl.handle.net/11536/25943
http://dx.doi.org/10.1039/c0jm04417b
ISSN: 0959-9428
DOI: 10.1039/c0jm04417b
期刊: JOURNAL OF MATERIALS CHEMISTRY
Volume: 21
Issue: 31
起始頁: 11605
結束頁: 11612
顯示於類別:期刊論文


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