Browsing by Author "Hong, L."

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    Effect of shell thickness on small-molecule solar cells enhanced by dual plasmonic gold-silica nanorods
    (AIP Publishing, 2014-09-19) Xu, X.; Du, Q.; Peng, B.; Xiong, Q.; Hong, L.; Demir, Hilmi Volkan; Wong, T. K. S.; Kyaw, A. K. K.; Sun, X. W.
    Chemically synthesized gold (Au)-silica nanorods with shell thickness of 0 nm-10 nm were incorporated into the bulk heterojunction of a small-molecule organic solar cell. At optimal (1 wt. %) concentration, Au-silica nanorods with 5 nm shell thickness resulted in the highest power conversion efficiency of 8.29% with 27% relative enhancement. Finite-difference time-domain simulation shows that the localized electric field intensity at the silica shell-organic layer interface decreases with the increase of shell thickness for both 520 nm and 680 nm resonance peaks. The enhanced haze factor for transmission/reflection of the organic layer is not strongly dependent on the shell thickness. Bare Au nanorods yielded the lowest efficiency of 5.4%. Light intensity dependence measurement of the short-circuit current density shows that the silica shell reduces bimolecular recombination at the Au surface. As a result, both localized field intensity and light scattering are involved in efficiency enhancement for an optimized shell thickness of 5 nm.
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    Enhanced efficiency of solution-processed small-molecule solar cells upon incorporation of gold nanospheres and nanorods into organic layers
    (Royal Society of Chemistry, 2014) Xu, X.; Kyaw, A. K. K.; Peng, B.; Du, Q.; Hong, L.; Demir, Hilmi Volkan; Wong, T. K. S.; Xiong, Q.; Sun, X. W.
    The significantly enhanced performance upon incorporation of Au nanoparticles in solution-processed small-molecule solar cells is demonstrated. Simultaneously incorporating Au nanospheres into the hole transport layer and Au-silica nanorods into the active layer results in superior broadband absorption improvement in the device with a power conversion efficiency of 8.72% with 31% enhancement.