title: Alloying Strategy in Cu-In-Ga-Se Quantum Dots for High Efficiency Quantum Dot Sensitized Solar Cells.
abstract: I-III-VI2group "green" quantum dots (QDs) are attracting increasing attention in photoelectronic conversion applications. Herein, on the basis of the "simultaneous nucleation and growth" approach, Cu-In-Ga-Se (CIGSe) QDs with light harvesting range of about 1000 nm were synthesized and used as sensitizer to construct quantum dot sensitized solar cells (QDSCs). Inductively coupled plasma atomic emission spectrometry (ICP-AES), wild-angle X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses demonstrate that the Ga element was alloyed in the Cu-In-Se (CISe) host. Ultraviolet photoelectron spectroscopy (UPS) and femtosecond (fs) resolution transient absorption (TA) measurement results indicate that the alloying strategy could optimize the electronic structure in the obtained CIGSe QD material, thus matching well with TiO2substrate and favoring the photogenerated electron extraction. Open circuit voltage decay (OCVD) and impedance spectroscopy (IS) tests indicate that the intrinsic recombination in CIGSe QDSCs was well suppressed relative to that in CISe QDSCs. As a result, CIGSe based QDSCs with use of titanium mesh supported mesoporous carbon counter electrode exhibited a champion efficiency of 11.49% (Jsc= 25.01 mA/cm2, Voc= 0.740 V, FF = 0.621) under the irradiation of full one sun in comparison with 9.46% for CISe QDSCs.
authors.affiliation: Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology , Shanghai 200237, China.
authors.forename: Wenxiang
authors.initials: W
authors.lastname: Peng
authors.affiliation: Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology , Shanghai 200237, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Du
authors.affiliation: Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology , Shanghai 200237, China.
authors.forename: Zhenxiao
authors.initials: Z
authors.lastname: Pan
authors.affiliation: Department of Engineering Science, University of Electro-Communications , Tokyo 182-8585, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Nakazawa
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Jiankun
authors.initials: J
authors.lastname: Sun
authors.affiliation: Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology , Shanghai 200237, China.
authors.forename: Zhonglin
authors.initials: Z
authors.lastname: Du
authors.affiliation: Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology , Shanghai 200237, China.
authors.forename: Gencai
authors.initials: G
authors.lastname: Shen
authors.affiliation: Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology , Shanghai 200237, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Yu
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Jin-Song
authors.identifier: http://orcid.org/0000-0002-6268-0959
authors.initials: JS
authors.lastname: Hu
authors.affiliation: Department of Engineering Science, University of Electro-Communications , Tokyo 182-8585, Japan.|Japan Science and Technology Agency (JST) , Saitama 332-0012, Japan.
authors.forename: Qing
authors.identifier: http://orcid.org/0000-0001-8359-3275
authors.initials: Q
authors.lastname: Shen
authors.affiliation: Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science and Technology , Shanghai 200237, China.|College of Materials and Energy, South China Agricultural University , 483 Wushan Road, Guangzhou 510642, China.
authors.forename: Xinhua
authors.identifier: http://orcid.org/0000-0002-2062-8773
authors.initials: X
authors.lastname: Zhong
keywords: Cu−In−Ga−Se (CIGSe) QDs; alloying strategy; high efficiency; photovoltaic cells; quantum dot sensitized solar cells