Publications (34) View all
-
Article: Coexistence of Femtosecond- and Nonelectron-Injecting Dyes in Dye-Sensitized Solar Cells: Inhomogeniety Limits the Efficiency
[show abstract] [hide abstract]
ABSTRACT: We performed a detailed and quantitative spectroscopic study of the electron injection dynamics for porphyrin as one of organic dyes at an adequate level to discuss the dyesensitized solar cell performance. The electron injection kinetics and the electron injection yield for dye sensitized TiO(2) electrodes in redox-containing electrolytes. were :measured by femtosecond transient absorption and picosecond fluorescence spectroscopy By comparing the dynamics of two of the most studied porphyrins with those of a Ru complex (N719), We have directly elucidated that the short-circuit current for the porphyrin-Sensitized solar cells is limited. by the presence of excited dyes that are quenched in the subnanosecond time range without competing with the electron injection process, even though both porphyrins shows faster injection processes within the picosecond time range than N719. Therefore, it was clearly indicated the electron injection efficiency was mainly limited by the inhomogeniety, which should be carefully considered for further development of organic dye-sensitized solar cells.Journal of Physical Chemistry C. 01/2011; 115(44):22084-22088. -
Article: Remarkable synergistic effects in a mixed porphyrin dye-sensitized TiO2 film
[show abstract] [hide abstract]
ABSTRACT: A remarkable 300% efficiency enhancement driven by a matching increase in the short circuit current was observed in a mixed porphyrin dye-sensitized solar cell constructed from two dyes in a 3: 1 ratio. Absorbed photon-to-current conversion efficiency measurements indicate an improved charge injection yield for both dyes in the mixture. Several possible origins for the observed performance enhancement are discussed. (C) 2011 American Institute of Physics. [doi:10.1063/1.3576904]Applied Physics Letters 01/2011; 98(16). · 3.84 Impact Factor -
Article: Significant Performance Improvement of Porphyrin-Sensitised TiO2 Solar Cells Under White Light Illumination
Journal of Physical Chemistry C. 01/2011; 115:317. -
Article: Charge Transport in Dye-Sensitized Solar Cells Based on Flame-made Nanoparticles
[show abstract] [hide abstract]
ABSTRACT: The fundamental understanding on charge-transport properties of flame-synthesized in dye-sensitized solar cells (DSSCs) is established in this work. By employing a one-step flame spray pyrolysis (FSP), predominantly anatase TiO<sub>2</sub> nanoparticles with average nanoparticle sizes between 11 and 36 nm were achieved by varying the rate of combustion enthalpy (through varying liquid precursor feed flow rates) and using either an “open-flame” or “enclosed-flame” configuration. Electron diffusion coefficient (D), electron lifetime (τ), open circuit voltage (V<sub>oc</sub>), and capacitance (C) measurements carried out on FSP TiO<sub>2</sub>-based DSSCs demonstrated that interband charge trap density decreased with increase in particle size. Compared to earlier studies, interband charge trap density could be controlled more independently of particle size. Under one-sun conditions, relatively high was measured with large particle size due to the lowering of interband charge trap density. This was true despite the associated shorter τ. Comparisons with commercial benchmark Nanoxide-T and Degussa P25 TiO<sub>2</sub> were also carried out. The results from the current study have significant implications on the design of TiO<sub>2</sub> nanoparticles by flame aerosol techniques, for DSSCs as well as other photoelectrochemical applications.IEEE Journal of Selected Topics in Quantum Electronics 01/2011; · 3.78 Impact Factor -
Chapter: Porphyrin Based Dye Sensitized Solar Cells
11/2011; , ISBN: 978-953-307-735-2
