| Summary: | <p>This thesis summarises the photoluminescence results I have taken on the three different
nanostructures of CsPbBr3 perovskite. Due to their microscopic dimensions, interesting
physics phenomena under the fields of optical science and quantum mechanics have emerged.
With the aid of a confocal micro-photoluminescence setup, detailed sub µm-level features
can be retrieved directly for analysis. Although the three topics root from separate branches
of specific physics fields, they all demonstrate how this system can be exploited as a general
tool for examining the time-integrated and dynamical behaviours. Therefore, the thesis
helps build the necessary knowledge for adaptation into different scenarios and external
modification for a more specialised measurement. On the other side, much of the content
has been devoted into systematic explanation of the relevant concepts in a self-contained
fashion. These include the discussion on lasing phenomenon, Gaussian modes and triplet
state. These recap or exposure to the different fields will be sufficient for the reader to
understand the rest of the content.</p>
<p>The results are selected from the three papers I have written. The first topic is on confined
Gaussian modes in CsPbBr<sub>3</sub> microcavities. These cavities are naturally formed by the even
smaller building blocks of quantum dots. The emission observed depends upon the collective
behaviour of the zero-dimensional objects. The second topic is relevant to triplet state and
resonant pumping of the CsPbBr<sub>3</sub> nanocrystals. Doubly degenerate states associated to the
tetragonal phase of the crystal have been presented. A resonantly optimised lasing effect
then builds on this triplet signal and shows great potential for device applications. The third
topic is about passivated CsPbBr<sub>3</sub> nano/micro-rods with Pb(OH)<sub>2</sub> cladding. A temperature-tolerant emission and bright stimulated emission from defect sites have been demonstrated.</p>
<p>All the three topics have illustrated the potential towards modern optoelectronic applications
and the underlying physics can provide further inspiration from a slightly twisted angle for
the future structure design.</p>
<p>In the appendix, a guide to the mapping software is introduced. This is a handy tool for
analysing the complicated map data, which can be a crucial part of the PL study. The software provides control over the map position and wavelength, as well as a diffusion analyser.
It also incorporates a zooming function such that local intensity rescaling is possible.</p>
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