title: Gold-silver@TiO2nanocomposite-modified plasmonic photoanodes for higher efficiency dye-sensitized solar cells.
abstract: In the present investigation, gold-silver@titania (Au-Ag@TiO2) plasmonic nanocomposite materials with different Au and Ag compositions were prepared using a simple one-step chemical reduction method and used as photoanodes in high-efficiency dye-sensitized solar cells (DSSCs). The Au-Ag incorporated TiO2photoanode demonstrated an enhanced solar-to-electrical energy conversion efficiency of 7.33%, which is ∼230% higher than the unmodified TiO2photoanode (2.22%) under full sunlight illumination (100 mW cm-2, AM 1.5G). This superior solar energy conversion efficiency was mainly due to the synergistic effect between the Au and Ag, and their surface plasmon resonance effect, which improved the optical absorption and interfacial charge transfer by minimizing the charge recombination process. The influence of the Au-Ag composition on the overall energy conversion efficiency was also explored, and the optimized composition with TiO2was found to be Au75-Ag25. This was reflected in the femtosecond transient absorption dynamics in which the electron-phonon interaction in the Au nanoparticles was measured to be 6.14 ps in TiO2/Au75:Ag25, compared to 2.38 ps for free Au and 4.02 ps for TiO2/Au100:Ag0. The slower dynamics indicates a more efficient electron-hole separation in TiO2/Au75:Ag25that is attributed to the formation of a Schottky barrier at the interface between TiO2and the noble metal(s) that acts as an electron sink. The significant boost in the solar energy conversion efficiency with the Au-Ag@TiO2plasmonic nanocomposite showed its potential as a photoanode for high-efficiency DSSCs.
authors.affiliation: School of Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900 Sepang, Selangor Darul Ehsan, Malaysia. supei529@gmail.com and Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia. huangnayming@um.edu.my.
authors.forename: Su Pei
authors.initials: SP
authors.lastname: Lim
authors.affiliation: Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia. huangnayming@um.edu.my.
authors.forename: Yee Seng
authors.initials: YS
authors.lastname: Lim
authors.affiliation: Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia. huangnayming@um.edu.my.
authors.forename: Alagarsamy
authors.initials: A
authors.lastname: Pandikumar
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. janet_limhn@science.upm.edu.my and Functional Device Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Hong Ngee
authors.initials: HN
authors.lastname: Lim
authors.affiliation: Particles and Catalysis Research Group, School of Chemical Engineering, The University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Yun Hau
authors.initials: YH
authors.lastname: Ng
authors.affiliation: Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia. huangnayming@um.edu.my and Department of Physical Chemistry, Centre for Photoelectrochemistry, School of Chemistry, Madurai Kamaraj University, Madurai-625 021, India.
authors.forename: Ramasamy
authors.initials: R
authors.lastname: Ramaraj
authors.affiliation: Nanoelectronics Cluster, MIMOS Berhad, Technology Park Malaysia, Kuala Lumpur 57000, Malaysia.
authors.forename: Daniel Chia Sheng
authors.initials: DC
authors.lastname: Bien
authors.affiliation: Department of Chemistry, Faculty of Science, Sultan Qaboos University, P. O. Box 36, Postal Code 123, Muscat, Sultanate of Oman. abouzied@squ.edu.om.
authors.forename: Osama K
authors.initials: OK
authors.lastname: Abou-Zied
authors.affiliation: Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia. huangnayming@um.edu.my.
authors.forename: Nay Ming
authors.identifier: http://orcid.org/0000-0002-0839-6578
authors.initials: NM
authors.lastname: Huang