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020 ▼a 9781085609463
035 ▼a (MiAaPQ)AAI13896874
040 ▼a MiAaPQ ▼c MiAaPQ ▼d 247004
0820 ▼a 620.11
1001 ▼a Dement, Dana Brooke.
24510 ▼a Complex Refractive Index Modeling and Nanoscale Patterning of Solid-State Colloidal Quantum Dots for Nanophotonic Applications.
260 ▼a [S.l.]: ▼b University of Minnesota., ▼c 2019.
260 1 ▼a Ann Arbor: ▼b ProQuest Dissertations & Theses, ▼c 2019.
300 ▼a 125 p.
500 ▼a Source: Dissertations Abstracts International, Volume: 81-02, Section: B.
500 ▼a Advisor: Ferry, Vivian E.
5021 ▼a Thesis (Ph.D.)--University of Minnesota, 2019.
506 ▼a This item must not be sold to any third party vendors.
520 ▼a The small size of photoluminescent, nanocrystal quantum dots (QDs) leads to a variety of unique optical properties that are well-suited to many optoelectronic devices and nanophotonic studies. Here, we demonstrate techniques to further improve the design of solid-state QD structures. A problem for many applications is that predicting the optical behavior of QD solids is difficult because the complex refractive index of QD solids is a composite quantity that is dependent on size, ligand chain length, and the deposition process of the QDs. To address this problem, we show that the intrinsic refractive index of neat CdSe/CdS QDs can be extracted from solution-state absorption data. We then show how this information can be used with effective medium approximations to describe the effective refractive index of QD films associated with a variety of QD sizes and packing fractions. Our predictions are verified experimentally by spectroscopic ellipsometry. With our modeling tool, we can also understand packing variations between QD films and predict the absorption in solid-state QD structures, leading to significant savings in both time and materials. Using the same QD materials, we next address the need for accurate patterning of QD solids at the nanoscale. We have found that direct electron beam lithography is a straightforward patterning process that does not require ligand exchange and results in structures that retain bright photoluminescence. We demonstrate that feature sizes as narrow as 30 nm with many QD layers can be patterned. These structures can withstand sonication in a variety of solvents, show no distortion, and can be placed within 20 nm of their intended location nearly 100% of the time. Combining our nanofabrication technique with the ability to measure the refractive index of the QD pattern, we find that edge effects arising from the finite shape of the QD nanostructure lead to substantial absorption enhancement when compared to an equivalent volume region taken from a continuous QD film. Finally, we explore more complex structures by patterning QD arrays, multilayer QD structures, and QD disks inside plasmonic resonators. We believe that the work presented here lays important groundwork to improve the modeling of QD solids and reveals new ways QDs can be incorporated into devices and nanophotonic designs.
590 ▼a School code: 0130.
650 4 ▼a Optics.
650 4 ▼a Nanotechnology.
650 4 ▼a Materials science.
690 ▼a 0794
690 ▼a 0752
690 ▼a 0652
71020 ▼a University of Minnesota. ▼b Material Science and Engineering.
7730 ▼t Dissertations Abstracts International ▼g 81-02B.
773 ▼t Dissertation Abstract International
790 ▼a 0130
791 ▼a Ph.D.
792 ▼a 2019
793 ▼a English
85640 ▼u http://www.riss.kr/pdu/ddodLink.do?id=T15491757 ▼n KERIS ▼z 이 자료의 원문은 한국교육학술정보원에서 제공합니다.
980 ▼a 202002 ▼f 2020
990 ▼a ***1008102
991 ▼a E-BOOK