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Photoelectrochemical and Electrochemical Characterization of Sub-Micro-Gram Amounts of Organic Semiconductors Using Scanning Droplet Cell Microscopy.

Kollender JP, Gasiorowski J, Sariciftci NS, Mardare AI, Hassel AW - J Phys Chem C Nanomater Interfaces (2014)

Bottom Line: The most attractive features of the PE-SDCM are represented by the possibility of addressing small areas on the investigated substrate and the need of small amounts of electrolyte.A very small amount (ng) of the material under study is sufficient for a complete electrochemical and photoelectrochemical characterization due to the scanning capability of the cell.The electrochemical behavior of the polymer was studied in detail using potentiostatic and potentiodynamic investigations as well as electrochemical impedance spectroscopy.

View Article: PubMed Central - PubMed

Affiliation: Institute for Chemical Technology of Inorganic Materials, Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, and Christian Doppler Laboratory for Combinatorial Oxide Chemistry at the Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University Linz , Altenberger Str. 69, 4040 Linz, Austria.

ABSTRACT
A model organic semiconductor (MDMO-PPV) was used for testing a modified version of a photoelectrochemical scanning droplet cell microscope (PE-SDCM) adapted for use with nonaqueous electrolytes and containing an optical fiber for localized illumination. The most attractive features of the PE-SDCM are represented by the possibility of addressing small areas on the investigated substrate and the need of small amounts of electrolyte. A very small amount (ng) of the material under study is sufficient for a complete electrochemical and photoelectrochemical characterization due to the scanning capability of the cell. The electrochemical behavior of the polymer was studied in detail using potentiostatic and potentiodynamic investigations as well as electrochemical impedance spectroscopy. Additionally, the photoelectrochemical properties were investigated under illumination conditions, and the photocurrents found were at least 3 orders of magnitude higher than the dark (background) current, revealing the usefulness of this compact microcell for photovoltaic characterizations.

No MeSH data available.


Related in: MedlinePlus

Measured open circuit potential in the darkand under illumination.
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fig10: Measured open circuit potential in the darkand under illumination.

Mentions: In addition to photocurrentmeasurements, the photopotential ofMDMO-PPV in TBAPF6 electrolyte was measured for 300 s,and the results are shown in Figure 10, asobtained from the open circuit potentials measured versus the referenceelectrode. When a space charge region is present at the semiconductingpolymer interface, the photoexcited electrons and holes are separatedand each one is moving in opposite direction under the influence ofthe electric field inside the space charge region. This field-assistedmigration of the photoexcited charge carriers induces an oppositepotential in the electrode which decreases the potential differenceacross the space charge region. This reduction further leads to shiftingof the Fermi level by a certain energy which can be detected by measuringthe photopotential.28 The electrode potentialin the dark continuously decreases from 0.13 V down to 0.05 V. Thistime variation can be related to the porous nature of the electrodemost likely being penetrated more and more by the electrolyte moleculeswith time. The photopotential measured under green light irradiationstays constant at about 0.46 V for about 50 s and then gradually decreasesto 0.22 V within the remaining 250 s of measurement time. However,this decrease is stronger than the decrease of the potential in theabsence of irradiation.


Photoelectrochemical and Electrochemical Characterization of Sub-Micro-Gram Amounts of Organic Semiconductors Using Scanning Droplet Cell Microscopy.

Kollender JP, Gasiorowski J, Sariciftci NS, Mardare AI, Hassel AW - J Phys Chem C Nanomater Interfaces (2014)

Measured open circuit potential in the darkand under illumination.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4120669&req=5

fig10: Measured open circuit potential in the darkand under illumination.
Mentions: In addition to photocurrentmeasurements, the photopotential ofMDMO-PPV in TBAPF6 electrolyte was measured for 300 s,and the results are shown in Figure 10, asobtained from the open circuit potentials measured versus the referenceelectrode. When a space charge region is present at the semiconductingpolymer interface, the photoexcited electrons and holes are separatedand each one is moving in opposite direction under the influence ofthe electric field inside the space charge region. This field-assistedmigration of the photoexcited charge carriers induces an oppositepotential in the electrode which decreases the potential differenceacross the space charge region. This reduction further leads to shiftingof the Fermi level by a certain energy which can be detected by measuringthe photopotential.28 The electrode potentialin the dark continuously decreases from 0.13 V down to 0.05 V. Thistime variation can be related to the porous nature of the electrodemost likely being penetrated more and more by the electrolyte moleculeswith time. The photopotential measured under green light irradiationstays constant at about 0.46 V for about 50 s and then gradually decreasesto 0.22 V within the remaining 250 s of measurement time. However,this decrease is stronger than the decrease of the potential in theabsence of irradiation.

Bottom Line: The most attractive features of the PE-SDCM are represented by the possibility of addressing small areas on the investigated substrate and the need of small amounts of electrolyte.A very small amount (ng) of the material under study is sufficient for a complete electrochemical and photoelectrochemical characterization due to the scanning capability of the cell.The electrochemical behavior of the polymer was studied in detail using potentiostatic and potentiodynamic investigations as well as electrochemical impedance spectroscopy.

View Article: PubMed Central - PubMed

Affiliation: Institute for Chemical Technology of Inorganic Materials, Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, and Christian Doppler Laboratory for Combinatorial Oxide Chemistry at the Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University Linz , Altenberger Str. 69, 4040 Linz, Austria.

ABSTRACT
A model organic semiconductor (MDMO-PPV) was used for testing a modified version of a photoelectrochemical scanning droplet cell microscope (PE-SDCM) adapted for use with nonaqueous electrolytes and containing an optical fiber for localized illumination. The most attractive features of the PE-SDCM are represented by the possibility of addressing small areas on the investigated substrate and the need of small amounts of electrolyte. A very small amount (ng) of the material under study is sufficient for a complete electrochemical and photoelectrochemical characterization due to the scanning capability of the cell. The electrochemical behavior of the polymer was studied in detail using potentiostatic and potentiodynamic investigations as well as electrochemical impedance spectroscopy. Additionally, the photoelectrochemical properties were investigated under illumination conditions, and the photocurrents found were at least 3 orders of magnitude higher than the dark (background) current, revealing the usefulness of this compact microcell for photovoltaic characterizations.

No MeSH data available.


Related in: MedlinePlus