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Accession Number:
AD1157271
Title:
Spectral and Temporal Response of UV-pumped Colloidal Quantum Dots in Polymer, Thin-film, and Additively-manufactured Structures
Descriptive Note:
[Technical Report, Memorandum Report]
Corporate Author:
Air Force Institute of TechnologyCenter for Integrated NanotechnologiesUNM Center for High Technology MaterialsLos Alamos National Laboratory
Report Date:
2022-01-21
Pagination or Media Count:
32
Abstract:
An interesting question regarding colloidal quantum dots CQDs was how do they compare in terms of both their photoluminescence PL spectra and UV-Vis PL lifetime decays in various structures This paper characterized both of these measurements using six commercially available CQD materials, these being CdS, CdSe, CdSe nanoplatelets NPLs, CdSeZnS, InPZnS, CuInSZnS. These nanocrystals were tested in the following structures CQD-loaded polymer matrix, thin-film, and CQDs dispersed within a 3D printed honeycomb structure. Over the course of the experiments the following effects were observed Charge-transfer CT, Frster resonance energy transfer FRET, and thermal oxidation. The time it took for CQD structures to decay from a experimentally derived modeled normalized intensity of 100 to 0.1 from UV-Vis excitation showed that the slowest decaying CQD loading structure was thin-film 12 ns to 144 ns while the fastest structure was CQD-loaded polymer matrix 945 ps to 20 ns. The 3D printed structure utilized SU-8-5 photoresist as a capping polymer to contain the CQDs. This resulted in all of the UV-Vis PL decay spectra for each nanocrystal material to become similar in values until the normalized intensity went below 1. The 100 to 0.1 normalized intensity decay time for the 3D printed structure was from 10 ns to 44 ns. Out of all of the nanomaterials tested under UV excitation, CdS was demonstrated to be the fastest PL decaying CQD with a 100 to 50 normalized intensity decay time as 545 ps when loaded within a polymer matrix.
Distribution Statement:
[A, Approved For Public Release]