Controlling light emission of nanoparticles

In this thesis we try to improve our understanding of how nanomaterials behave and how we can manipulate their light interactions. Light interactions play an important role in many technologies. LEDs, solar cells and lasers rely on interactions with light. Nanomaterials have the potential to allow the use of materials that were previously unsuitable or enable new processes using the same materials. The light observed from the materials studied originates from the nanoparticles within them: semiconductor nanocrystals (silicon and CsPbX₃ perovskites) and rare-earth ions (erbium, europium and ytterbium). The study concentrates on the light interaction properties of these nanomaterials, and how to manipulate the materials and influence the resulting light emission.
A unique selling point of nanocrystals is that the bandgap energy, i.e. the frequency of light with which the nanoparticles interact can be easily tuned by their size. But also the composition, rare-earth dopants, distance between nanoparticles, and the structure in which the nanocrystals are embedded can all be modified. These properties are the properties manipulated in order to explore the properties and functionalities. Besides manipulation we also try to understand how and why these nanomaterials behave the way they do. The nanocrystals can be put into different states by the light we shine on them and the temperature they are at. In this way we get insight into their inner workings, their electrons, and the processes that drive them. Ultimately, the insights obtained can be used to better design and implement nanomaterials in future devices.