Browsing by Subject "Carrier concentration"
Now showing items 1-14 of 14
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Concentration and excitation effects on the exciton dynamics of poly(3-hexylthiophene)/PbS quantum dot blend films
(2013)The dynamics of photoexcitations in hybrid blends of poly(3-hexylthiophene) (P3HT) conjugated polymer donor and oleic-acid capped lead sulfide (PbS) quantum dot (QD) acceptors of different concentrations - for light ...
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Article
Electronic Structure and Thermoelectric Properties of Pseudoquaternary Mg2Si1-x-ySnxGey-Based Materials
(2014)A theoretical study is presented on complex pseudoternary Bi-doped Mg2Si1-x-ySnxGey materials, which have recently been revealed to reach high thermoelectric figures of merit (ZT) of ∼1.4. Morphological characterization ...
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Femtosecond carrier dynamics of Inx Ga1-x N thin films grown on GaN (0001): Effect of carrier-defect scattering
(2007)Ultrafast carrier dynamics in ultrathin Inx Ga1-x N ternary alloys were investigated in detail, using femtosecond transient differential optical absorption measurements. Measurements were performed with probing wavelengths ...
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Indium oxide as a possible tunnel barrier in spintronic devices
(2005)We report the growth of ultra-thin indium oxide layers using the dc-magnetron sputtering method. We demonstrate that good quality tunnel barriers made of indium oxide can be routinely fabricated and employed in spintronic-related ...
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Light-induced mobility enhancement in delta-doped GaAs/In0.26Ga0.74As/GaAs quantum wells grown by molecular beam epitaxy on GaAs(001)
(1999)Persistent photoconductivity in 80 angstroms strained GaAs/In0.26Ga0.74As/GaAs quantum wells was investigated by measuring the Shubnikov de Haas and Hall effects at 4.2 K. The quantum wells were grown by molecular beam ...
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Article
Modification of thermoelectric properties using insertion techniques
(1999)In this work is presented the application insertion techniques for the modification of the performance of thermoelectric materials. The results indicate that in cases as in Bi2Se3 compounds where insertion of foreign species ...
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Probing carrier dynamics in implanted and annealed polycrystalline silicon thin films using white light
(2006)Polycrystalline silicon thin film samples implanted and annealed at various temperatures have been studied using ultrafast laser pulse excitation. Nondegenerate pump-probe technique has been utilized to investigate carrier ...
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Properties of Si-doped GaN and AlGaN/GaN heterostructures grown by RF-MBE on high resistivity Fe-doped GaN
(2006)Silicon-doped GaN epilayers and AlGaN/GaN heterostructures were developed by nitrogen plasma-assisted molecular beam epitaxy on high resistivity iron-doped GaN (0001) templates and their properties were investigated by ...
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SAXS Investigation of ABC Triblock Star Terpolymers in Aqueous Solution
(2004)The structure of three different ABC triblock star terpolymers in aqueous solution has been investigated by small-angle x-ray scattering (SAXS). The form factor was modeled using an analytical expression for a Gaussian ...
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Symmetry of differential optical responses of normal and superconducting phases in single-crystal YBCO
(1995)We measured differential optical reflectivity (DOR) of YBCO single domains. DOR measurements reject the temperature independent bulk reflectivity and reveal dR dT. These measurements detect the superconducting transition, ...
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Temporal evolution of effects of ultrafast carrier dynamics in In 0.33Ga0.67N: Above and near the bandgap
(2007)Ultrafast carrier dynamics in the In0.33Ga0.67N epilayer were investigated in detail, using femtosecond transient differential non-degenerate optical absorption measurements. Following an excitation at 400 nm with fluence ...
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Article
Thermoelectric properties and site-selective Rb+/K+ distribution in the K2-xRbxBi8Se13 series
(2003)β-K2Bi8Se13 possesses promising thermoelectric properties whereas Rb2Bi8Se13 does not. The formation of solid solutions between these two compounds was attempted to study the alkali metal distribution in the structure and ...
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Thermoelectric properties of nanocrystalline PbTe synthesized by mechanical alloying
(2010)In this work, nanocrystalline lead telluride powder was synthesized from high-purity elements by mechanical alloying by means of a planetary ball-milling procedure. The milling medium was tungsten carbide, and the diameter ...
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Ultrafast carrier dynamics on conjugated poly(3-hexylthiophene)/[6,6]- phenyl C61 -butyric acid methyl ester composites
(2007)The authors have studied ultrafast carrier dynamics on poly(3- hexylthiophene)/[6,6]- phenyl C61 -butyric acid methyl ester (PCBM) composites up to 50% PCBM concentration. They have resolved the exciton intraband relaxation ...