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Date of Award


Document Type

Campus Access Dissertation

Degree Name

Doctor of Philosophy in Physics (PhD)

Administrative Home Department

Department of Physics

Advisor 1

Dongyan Zhang

Advisor 2

Yoke Khin Yap

Committee Member 1

Ranjit Pati

Committee Member 2

Smitha Rao

Committee Member 3

John Jaszczak


The popularity of boron nitride nanomaterials for their application in areas like electronics, photovoltaic, biomedical, automobile, and so on has increased in the recent era. Some unique properties make BNNTs outstanding for biomedical and photovoltaic applications, such as their optical transparency, electrical insulation, and biological compatibility. Hence large-scale synthesis of high-purity small-diameter BNNTs is required. On the other hand, research on the origin of excitation-dependent fluorescence (EDF) in BN dots is in its infancy. So, in this dissertation, we studied the growth mechanism of high-purity BNNTs with diameters smaller than 30nm. Additionally, we synthesized two different types of BN dots [sonication-assisted solvothermal (ss) BN dots and liquid nitrogen (LN) exfoliated BN dots], and studied their fluorescent properties. For the first time, we exploited the EDF property of the ss BN dots for solar cells. Here, we define ss BN dots as a pseudo-core/shell structure of DMA-CO and BN nanosheets and use them as the solar absorber (active layers, AL) to yield an efficiency of 1.51%. Our work is the first demonstration using biological and environmentally friendly colloidal nanomaterials for solar cells. In addition, we determined, for the first time, the biocompatible doses of ss BN dots for use in live HeLa cells. We found ss BN dots are suitable for live cell staining at doses below <10mg/mL for four consecutive days. We further investigated the photophysical properties of ss BN dots as fluorescent probes. We also demonstrated bright fluorescent staining of live HeLa cells using high-brightness fluorophores (HBFs) produced by our collaborators based on BN dots.