Abstract: Understanding and controlling the ultrafast charge carrier and exciton dynamics at the interface of semiconductor nanocrystals (NCs) offer an excellent opportunity to improve the charge
collection and the overall performance of many optoelectronic and energy-based devices. In this
dissertation, we study how interfacial engineering of these materials can have a direct influence
on controlling the charge transfer and the nonradiative losses in different donor-acceptor
systems. The first introductory chapter provides an overview of all the fundamental
photophysical processes controlling the interfacial phenomena. Then, the second chapter
highlights all the chemicals and synthesis methods employed during this thesis. The subsequent
two chapters discuss the detailed experimental studies and observations related to different
materials and interfaces. First, it describes how we can dramatically tune the intersystem crossing
(ISC) rate, the triplet state lifetime, turn on/off the electron injection at the CdTe-Prophyrin interface
via tuning either the quantum dot size or the porphyrin molecular structure. Also, how the
intermolecular distances, electronic coupling, and subsequently, the photoinduced charge
transfer can be controlled by the interfacial electrostatic interactions at CdTe-Fullerene
interfaces. Second, due to the promise that of perovskite NCs holds for improving many solar cell
and optoelectronic applications, chapter 3 highlights the tremendous effect that the shape of
perovskite nanocrystals has on the rate and the mechanism of charge transfer at the MAPbBr3-
TCNE interface. Besides, it demonstrates how the confinement effect brought by changing the
dimensionality influence the charge transfer dynamics at the MAPbBr3-BQ interface. Finally, it
explains how the effective passivation of the surface defects and the subsequent suppression of
the formation of surface nonradiative recombination centers in CsPbCl3 NCs controls the
photoluminescence quantum yield and the photodetector performance.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/661839 |
| Date | 01 1900 |
| Creators | Ahmed, Ghada H. |
| Contributors | Mohammed, Omar F., Physical Science and Engineering (PSE) Division, Huang, Kuo-Wei, Kamat, Prashant V., Bakr, Osman |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
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