title: Broadband energy transfer to sensitizing dyes by mobile quantum dot mediators in solar cells.
abstract: The efficiency of solar cells depends on absorption intensity of the photon collectors. Herein, mobile quantum dots (QDs) functionalized with thiol ligands in electrolyte are utilized into dye-sensitized solar cells. The QDs serve as mediators to receive and re-transmit energy to sensitized dyes, thus amplifying photon collection of sensitizing dyes in the visible range and enabling up-conversion of low-energy photons to higher-energy photons for dye absorption. The cell efficiency is boosted by dispersing QDs in electrolyte, thereby obviating the need for light scattering or plasmonic structures. Furthermore, optical spectroscopy and external quantum efficiency data reveal that resonance energy transfer due to the overlap between QD emission and dye absorption spectra becomes dominant when the QD bandgap is higher than the first excitonic peak of the dye, while co-sensitization resulting in a fast reduction of oxidized dyes is pronounced in the case of lower QD band gaps.
authors.affiliation: 1] Graduate School of EEWS (WCU), Department of Materials Science and Engineering, KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea [2].
authors.forename: Gede Widia Pratama
authors.initials: GW
authors.lastname: Adhyaksa
authors.forename: Ga In
authors.initials: GI
authors.lastname: Lee
authors.forename: Se-Woong
authors.initials: SW
authors.lastname: Baek
authors.forename: Jung-Yong
authors.initials: JY
authors.lastname: Lee
authors.forename: Jeung Ku
authors.initials: JK
authors.lastname: Kang
references.citation: Nano Lett. 2011 Mar 9;11(3):1227-31
references.pmid: 21314162
references.citation: Nano Lett. 2001 Apr;1(4):207-211
references.pmid: 35897166
references.citation: ACS Nano. 2010 Jun 22;4(6):3374-80
references.pmid: 20496882
references.citation: Science. 2011 Dec 16;334(6062):1530-3
references.pmid: 22174246
references.citation: Nat Mater. 2009 Aug;8(8):683-9
references.pmid: 19597500
references.citation: ACS Nano. 2011 Sep 27;5(9):7108-16
references.pmid: 21815674
references.citation: J Phys Chem Lett. 2012 Feb 16;3(4):556-9
references.pmid: 26286060
references.citation: J Am Chem Soc. 2009 Jul 29;131(29):9876-7
references.pmid: 19583203
references.citation: Nat Mater. 2011 May;10(5):361-6
references.pmid: 21478881
references.citation: Nat Mater. 2011 Oct 09;10(12):974-9
references.pmid: 21983889
references.citation: Opt Express. 2007 Oct 1;15(20):12818-33
references.pmid: 19550551
references.citation: Langmuir. 2007 Oct 23;23(22):10906-9
references.pmid: 17880255