مجال
التميز
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تميز دراسي و بحثي
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البحوث المنشورة
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البحث (1):
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عنوان البحث:
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An Ionic Liquid-Gated Polymer Thin Film
Transistor With Exceptionally Low “On” Resistance
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رابط إلى البحث:
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here
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تاريخ النشر:
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05/05/2014
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موجز عن البحث:
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We report the ionic liquid (IL) gating
of a solution processed semiconducting polymer,
poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT).
IL gating relies on the poor solubility of PBTTT, which requires hot
chlorinated benzenes for solution processing. PBTTT, thus, resists
dissolution even in IL, which otherwise rapidly dissolves semiconducting
polymers. The resulting organic thin film transistors (OTFTs) display low
threshold, very high carrier mobility (>3 cm2/Vs), and deliver high currents
(in the order of 1 mA) at low operational voltages. Such OTFTs are
interesting both practically, for the addressing of current-driven devices
(e.g., organic LEDs), and for the study of charge transport in semiconducting
polymers at very high carrier density.
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البحث (2):
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عنوان البحث:
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Precursor-Route
Zno Films From A Mixed Casting Solvent For High Performance Aqueous
Electrolyte-Gated Transistors
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تاريخ النشر:
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26/10/2015
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موجز عن البحث:
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We significantly improved the
performance of precursor-route semiconducting zinc oxide (ZnO) films in
electrolyte-gated thin film transistors (TFTs). We find that the organic
precursor to ZnO, zinc acetate (ZnAc), dissolves more readily in a 1
:
1
mixture of ethanol (EtOH) and acetone than in pure EtOH, pure acetone, or
pure isopropanol. XPS and SEM characterisation show improved morphology of
ZnO films converted from a mixed solvent cast ZnAc precursor compared to the
EtOH cast precursor. When gated with a biocompatible electrolyte, phosphate
buffered saline (PBS), ZnO thin film transistors (TFTs) derived from mixed
solvent cast ZnAc give 4 times larger field effect current than similar films
derived from ZnAc cast from pure EtOH. The sheet resistance
at VG = VD = 1 V is 30 kΩ □−1, lower than for any organic
TFT, and lower than for any electrolyte-gated ZnO TFT reported to date.
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البحث (3):
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عنوان البحث:
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A Water-Gated
Organic Thin Film Transistor As A Sensor For Water-Borne Amines
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تاريخ النشر:
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01/06/2016
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موجز عن البحث:
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The p-type semiconducting polymer Poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene)
(PBTTT) displays innate sensitivity to water-borne amines. We demonstrate
this with the help of water-gated PBTTT thin film transistors (TFTs). When
octylamine is added to the gating water, TFTs respond with a significantly
reduced saturated drain current. Underlying TFT drift is minimised by initial
conditioning, and remaining drift can be accounted for by normalising current
response to the current level under purge immediately before exposure. Normalised
current response vs. amine concentration is reproducible between
different transistors, and can be modelled by a Langmuir surface adsorption
isotherm, which suggests physisorption of analyte at the PBTTT surface,
rather than bulk penetration. Same PBTTT transistors do not respond to 1-
octanol, confirming the specific affinity between amines and thiophene- based
organic semiconductors.
Graphical abstract
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البحث (4):
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عنوان البحث:
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A
membrane-free cation selective water-gated transistor
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تاريخ النشر:
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19/07/2016
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موجز عن البحث:
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Sensors for the detection of waterborne
cations are of great practical interest, and chemistry has synthesised a
formidable catalogue of cation selective complexation agents (‘ionophores’)
as selective sensitisers. Current ionophore-based sensors separate the
complexation of the cation by the ionophore, and the transduction of
complexation into an electrical signal, into separate components. We here
unite both functions into a single, sensitised semiconducting layer of a
water-gated organic thin film transistor (OTFT). The resulting OTFT
transduces waterborne cations into an electrical signal with same
selectivity, sensitivity, and limit of detection as established sensors at
much simplified preparation and operation. This opens a new route to apply
the ‘ionophore’ family of functional organic materials in practical cation
sensors.
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البحث (5):
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عنوان البحث:
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Innate
Cation Sensitivity In A Semiconducting Polymer
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رابط إلى البحث:
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here
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تاريخ النشر:
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01/09/2016
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موجز عن البحث:
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Water-gated organic thin film transistors (OTFTs) using the hole
transporting semiconducting polymer,
poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT), show
an innate response of their threshold voltage to the addition of divalent metal
cations to the gating water, without deliberately introducing an
ion-sensitive component. A similar threshold response is shown for several
divalent cations, but is absent for monovalent cations. Response is absent
for transistors using the inorganic semiconductor ZnO, or the similar organic
semiconductor poly(3-hexylthiophene) (rrP3HT), instead of PBTTT. We assign
innate cation sensitivity to residues of the organometallic Pd(0) complex
used as catalyst in PBTTT synthesis which bears strong resemblance to typical
metal chelating agents. Organometallic Pd(0) residues are absent from ZnO,
and also from rrP3HT which is polymerised with a different type of catalyst.
However, when Pd(0) complex is deliberately added to rrP3HT casting
solutions, resulting OTFTs also display threshold response to a divalent
cation.
Graphical abstract
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المؤتمرات العلمية:
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المؤتمر (1):
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عنوان المؤتمر:
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UK
Semiconductors 2014 Conference
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تاريخ الإنعقاد:
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09/07/2014
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مكان
الإنعقاد:
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Sheffield.
UK
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طبيعة المشاركة:
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Poster
presentation
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عنوان المشاركة:
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An Ionic
Liquid- Gated Polymer Thin Film Transistor With Exceptionally Low ‘On’
Resistance
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ملخص المشاركة:
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We
present the first ionic liquid (IL) gating of a high mobility solution
processed semiconducting polymer, poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-
b]thiophene) (PBTTT). IL gating relies on the poor solubility of PBTTT, which
resists dissolution even in IL. Resulting organic thin film transistors
(OTFTs) display low threshold, very high carrier mobility (>3cm2/Vs), and
deliver high currents (in the order of 1mA) at low voltages.
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المؤتمر (2):
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عنوان المؤتمر:
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UK Semiconductors
2016 Conference
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تاريخ الإنعقاد:
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07/07/2016
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مكان
الإنعقاد:
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Sheffield.
UK
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طبيعة المشاركة:
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Poster
presentation
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عنوان المشاركة:
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Sensing Waterborne Analytes With Water-Gated Thin
Film Transistors (TFTs)
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ملخص المشاركة:
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The
gating of semiconducting films by water [1] has paved the way for a new
sensor technology for waterborne analytes. Here the sample works as active
part of a thin film transistor (TFT) that transduces the presence of analyte
via its electrical characteristics. Sensitivity and selectivity rely on the
interactions of analyte either with the semiconductor itself, or with a
sensitiser that is deliberately introduced into the TFT architecture. We here
present water- gated TFT sensors with sensitivity to biologically relevant
analytes, namely amine, and calcium cations. We establish ‘Langmuirish’ vs.
‘Nernstian‘ characteristics, and selectivity over interferants.
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