Contactless Determination of the Photoconductivity Action Spectrum, Exciton Diffusion Length, and Charge Separation Efficiency in Polythiophene-Sensitized TiO2Bilayers

2003 ◽  
Vol 107 (31) ◽  
pp. 7696-7705 ◽  
Author(s):  
Jessica E. Kroeze ◽  
Tom J. Savenije ◽  
Martien J. W. Vermeulen ◽  
John M. Warman
Keyword(s):  
Charge Separation ◽  
Diffusion Length ◽  
Separation Efficiency ◽  
Action Spectrum ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length ◽  
Charge Separation Efficiency

scholarly journals Effect of Quencher, Geometry, and Light Out‐Coupling on the Determination of Exciton Diffusion Length in Non‐Fullerene Acceptors

Solar RRL ◽  
2021 ◽  
Author(s):  
Valentina Belova ◽  
Aleksandr Perevedentsev ◽  
Julien Gorenflot ◽  
Catherine S. P. De Castro ◽  
Miquel Casademont-Viñas ◽  
...  
Keyword(s):  
Diffusion Length ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length

Peak Force Visible Microscopy for Determination of Exciton Diffusion Length in Organic Photovoltaic Blends

2018 ◽  
Author(s):  
Haomin Wang ◽  
Le Wang ◽  
Yuequn Shang ◽  
Zhijun Ning ◽  
Xiaoji Xu
Keyword(s):  
Diffusion Length ◽  
Spectroscopic Technique ◽  
Peak Force ◽  
Organic Photovoltaic ◽  
Phase Separations ◽  
Blend Films ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length ◽  
Atomic Force

In this article, we developed a new nano spectroscopic technique, peak force visible (PF-vis) microscopy, which is based on the peak force tapping mode in an atomic force microscope to both visualize nanoscale morphology and estimate exciton diffusion lengths of donor domains in organic photovoltaic blends. Nano phase-separations in P3HT:PCBM and TFB:PCBM blend films were clearly revealed by PF-vis microscopy with a high spatial resolution less than 10 nm. A model that correlates PF-vis signal and the exciton diffusion length was also developed to estimate the diffusion lengths of P3HT and TFB to be 2.9±0.3 and 9.0±1.5 nm, respectively. PF-vis microscopy is expected to assist the evaluation of OPV materials, therefore accelerating the pace of innovation of OPVs.

Determination of Singlet Exciton Diffusion Length in Thin Evaporated C60 Films for Photovoltaics

2012 ◽  
Vol 3 (17) ◽  
pp. 2367-2373 ◽  
Author(s):  
Maria C. Fravventura ◽  
Jaehyung Hwang ◽  
John W. A. Suijkerbuijk ◽  
Peter Erk ◽  
Laurens D. A. Siebbeles ◽  
...  
Keyword(s):  
Diffusion Length ◽  
Singlet Exciton ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length ◽  
C60 Films

Determination of exciton diffusion length from photoconductivity low-temperature spectra

1971 ◽  
Vol 48 (2) ◽  
pp. 473-480 ◽  
Author(s):  
B. V. Novikov ◽  
A. V. Ilinskii ◽  
K. F. Lieder ◽  
N. S. Sokolov
Keyword(s):  
Low Temperature ◽  
Diffusion Length ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length ◽  
Temperature Spectra

Electron Diffusion Length and Charge Separation Efficiency in Nanostructured Ternary Metal Vanadate Photoelectrodes

2018 ◽  
Vol 941 ◽  
pp. 2121-2127
Author(s):  
Siti Nur'ain Binti Haji Yassin ◽  
Nur Afifah Haniyyah Halidi ◽  
Soong Leong Sim ◽  
Ye Ru Liu ◽  
James Robert Jennings
Keyword(s):  
Charge Separation ◽  
Diffusion Length ◽  
Separation Efficiency ◽  
Diffusion Reaction ◽  
Electron Diffusion ◽  
Simple Diffusion ◽  
Co Catalyst ◽  
Ternary Metal ◽  
Charge Separation Efficiency ◽  
Electron Diffusion Length

Ternary metal vanadates have recently emerged as promising photoelectrode materials for sunlight-driven water splitting. Here, we show that highly active nanostructured BiVO4films can be deposited onto fluorine-doped tin oxide (FTO) substrates by a facile sequential dipping method known as successive ionic layer adsorption and reaction (SILAR). After annealing and deposition of a cobalt phosphate (Co-Pi) co-catalyst, the photoelectrodes produce anodic photocurrents (under 100 mW cm-2broadband illumination, 1.23 Vvs. RHE) in pH 7 phosphate buffer that are on par with the highest reported in the literature for similar materials. To gain insight into the reason for the good performance of the deposited films, and to identify factors limiting their performance, incident photon-to-electron conversion efficiency spectra have been analyzed using a simple diffusion–reaction model to quantify the electron diffusion length (Ln; the average distance travelled before recombination) and charge separation efficiency (ηsep) in the films. The results indicate thatηsepapproaches unity at sufficiently positive applied potential but the photocurrent is limited by significant charge collection losses due to a shortLnrelative to the film thickness. The Co-Pi catalyst is found to improveηsepat low potentials as well as increaseLnat all potentials studied. These findings help to clarify the role of the Co-Pi co-catalyst and show that there could be room for improvement of BiVO4photoanodes deposited by SILAR ifLncan be increased.

Peak Force Visible Microscopy for Determination of Exciton Diffusion Length in Organic Photovoltaic Blends

2018 ◽  
Author(s):  
Haomin Wang ◽  
Le Wang ◽  
Yuequn Shang ◽  
Zhijun Ning ◽  
Xiaoji Xu
Keyword(s):  
Diffusion Length ◽  
Spectroscopic Technique ◽  
Peak Force ◽  
Organic Photovoltaic ◽  
Phase Separations ◽  
Blend Films ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length ◽  
Atomic Force

In this article, we developed a new nano spectroscopic technique, peak force visible (PF-vis) microscopy, which is based on the peak force tapping mode in an atomic force microscope to both visualize nanoscale morphology and estimate exciton diffusion lengths of donor domains in organic photovoltaic blends. Nano phase-separations in P3HT:PCBM and TFB:PCBM blend films were clearly revealed by PF-vis microscopy with a high spatial resolution less than 10 nm. A model that correlates PF-vis signal and the exciton diffusion length was also developed to estimate the diffusion lengths of P3HT and TFB to be 2.9±0.3 and 9.0±1.5 nm, respectively. PF-vis microscopy is expected to assist the evaluation of OPV materials, therefore accelerating the pace of innovation of OPVs.

Surface Engineering of Metal Oxide Photoelectrodes for Improved Band Alignment in Solar Water Splitting Cells

2016 ◽  
Vol 879 ◽  
pp. 832-837 ◽  
Author(s):  
Soong Leong Sim ◽  
Ye Ru Liu ◽  
Ying Woan Soon ◽  
James Robert Jennings
Keyword(s):  
Metal Oxide ◽  
Water Splitting ◽  
Charge Separation ◽  
Diffusion Length ◽  
Separation Efficiency ◽  
Electron Diffusion ◽  
Solar Water ◽  
Solar Water Splitting ◽  
Charge Separation Efficiency ◽  
Electron Diffusion Length

Several earth-abundant transition-metal oxides (e.g. Fe2O3, CoO, and Cu2O) possessing suitable band gaps for solar water splitting exist, but energy level alignment is often sub-optimal, i.e. the conduction and valence bands do not straddle the water oxidation and reduction potentials. Here, using a nanocrystalline-TiO2-based photoelectrochemical cell as a model system, we investigate the effect of tuning the semiconductor energy levels by adding Li+ ions to the electrolyte. The effect of LiClO4 addition on band edges, interfacial recombination resistance, electron diffusion length, and charge-separation efficiency were quantified by impedance spectroscopy and analysis of incident photon-to-current efficiency spectra. We find that the TiO2 band edges are shifted toward positive potentials by the addition of Li+, and that this increases the apparent electron diffusion length without affecting the charge-separation efficiency, most likely due to a change in the driving force for O2 reduction. These results should prove useful in the modeling and optimization of solar water splitting cells employing metal oxide photoelectrodes.

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