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Ultrafast Fluorescence Upconversion ...

Freymeyer, Nathaniel Johnson.

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Ultrafast Fluorescence Upconversion of Alloyed III-V/II-VI Core/Shell Quantum Dots.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Ultrafast Fluorescence Upconversion of Alloyed III-V/II-VI Core/Shell Quantum Dots./
Author:	Freymeyer, Nathaniel Johnson.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2020,
Description:	106 p.
Notes:	Source: Dissertations Abstracts International, Volume: 82-03, Section: B.
Contained By:	Dissertations Abstracts International82-03B.
Subject:	Physical chemistry. -
Online resource:	https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28163818
ISBN:	9798662599901

Ultrafast Fluorescence Upconversion of Alloyed III-V/II-VI Core/Shell Quantum Dots.
Freymeyer, Nathaniel Johnson.

Ultrafast Fluorescence Upconversion of Alloyed III-V/II-VI Core/Shell Quantum Dots. - Ann Arbor : ProQuest Dissertations & Theses, 2020 - 106 p.

Source: Dissertations Abstracts International, Volume: 82-03, Section: B.

Thesis (Ph.D.)--Vanderbilt University, 2020.

This item must not be sold to any third party vendors.

Colloid quantum dots (QDs) are semiconductor nanocrystals that can be tuned to emit specific wavelengths of light based upon their size. Maintaining long-term brightness of QDs is crucial towards their applications. Achieving this brightness requires effective surface passivation. Ultrafast fluorescence upconversion spectroscopy allows these ensemble charge carriers and trapping dynamics to be monitored. The obtained femtosecond decay constants and relative amplitudes show the effectiveness of surface passivation and allow direct comparisons to what has been previously observed for other QD systems. InP QDs are being developed as an alternative to those that contain the heavy metal cadmium with bright and stable InP/ZnSe being the most promising. Because of their poor stability in air, the ZnSe shell is often added prior to purification resulting in indium incorporation in the ZnSe shell. Since the effect of this indium alloy is unknown, two distinct interfaces in thick-shell InP/ZnSe III-V/II-VI QDs were synthesized and investigated: alloy and core/shell. The ultrafast carrier dynamics showed that indium incorporation into the shell was detrimental towards charge carrier recombination due to the charge imbalance caused by replacing a Zn2+ in the ZnSe shell with an In3+. To fully confine the charge carriers to the InP core, the extent of indium alloying needs to be minimized, and the surface requires further passivation.

ISBN: 9798662599901Subjects--Topical Terms:

1981412
Physical chemistry.
Subjects--Index Terms:

Semiconductor

Ultrafast Fluorescence Upconversion of Alloyed III-V/II-VI Core/Shell Quantum Dots.
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100 1 $a Freymeyer, Nathaniel Johnson. $3 3564273
245 1 0 $a Ultrafast Fluorescence Upconversion of Alloyed III-V/II-VI Core/Shell Quantum Dots.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2020
300 $a 106 p.
500 $a Source: Dissertations Abstracts International, Volume: 82-03, Section: B.
500 $a Includes supplementary digital materials.
500 $a Advisor: Rosenthal, Sandra J.
502 $a Thesis (Ph.D.)--Vanderbilt University, 2020.
506 $a This item must not be sold to any third party vendors.
520 $a Colloid quantum dots (QDs) are semiconductor nanocrystals that can be tuned to emit specific wavelengths of light based upon their size. Maintaining long-term brightness of QDs is crucial towards their applications. Achieving this brightness requires effective surface passivation. Ultrafast fluorescence upconversion spectroscopy allows these ensemble charge carriers and trapping dynamics to be monitored. The obtained femtosecond decay constants and relative amplitudes show the effectiveness of surface passivation and allow direct comparisons to what has been previously observed for other QD systems. InP QDs are being developed as an alternative to those that contain the heavy metal cadmium with bright and stable InP/ZnSe being the most promising. Because of their poor stability in air, the ZnSe shell is often added prior to purification resulting in indium incorporation in the ZnSe shell. Since the effect of this indium alloy is unknown, two distinct interfaces in thick-shell InP/ZnSe III-V/II-VI QDs were synthesized and investigated: alloy and core/shell. The ultrafast carrier dynamics showed that indium incorporation into the shell was detrimental towards charge carrier recombination due to the charge imbalance caused by replacing a Zn2+ in the ZnSe shell with an In3+. To fully confine the charge carriers to the InP core, the extent of indium alloying needs to be minimized, and the surface requires further passivation.
590 $a School code: 0242.
650 4 $a Physical chemistry. $3 1981412
650 4 $a Inorganic chemistry. $3 3173556
653 $a Semiconductor
653 $a Nanocrystals
653 $a Ultrafast spectroscopy
653 $a Alloy nanocrystals
653 $a Charge carrier dynamics
653 $a Nanocrystal surface chemistry
653 $a Fluorescence
653 $a upconversion
690 $a 0494
690 $a 0488
710 2 $a Vanderbilt University. $3 1017501
773 0 $t Dissertations Abstracts International $g 82-03B.
790 $a 0242
791 $a Ph.D.
792 $a 2020
793 $a English
856 4 0 $u https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28163818