Public defence in Engineering Physics, M.Sc. Shaochen Zhou

Title of the doctoral thesis: Photoluminescent Gold Nanoclusters in Soft matrices

Doctoral student: Shaochen Zhou
Opponent: Prof.Alexander P. Demchenko, Yuri Fedkovich Chernivtsi State University, Ukraine
Custos: Prof. Robin Ras, Aalto University School of Science, Department of Applied Physics

The research presented in this study focuses on a specific category of extremely small materials known as gold nanoclusters. These nanoclusters consist of only a few dozen gold atoms and exhibit photoluminescent properties, making them highly promising for various applications such as imaging, sensing, lighting, and more. Consequently, understanding the photoluminescence characteristics of gold nanoclusters holds significant importance both in terms of fundamental knowledge and practical applications. 

However, optimizing the performance of photoluminescence in gold nanoclusters poses considerable challenges due to their ultra-small size. These clusters are highly surface-active, chemically unstable, and susceptible to environmental conditions. In order to tackle this issue, this study discovers that by confining gold nanoclusters within soft matrices such as assemblies, layered structures, and polymers, it becomes feasible to engineer their properties effectively. Notably, this strategy greatly enhances the photoluminescence efficiency and stability, largely overcoming the drawbacks associated with these photoluminescent materials. Furthermore, specific soft matrices can yield intriguing functional properties like stimulus-responsive photoluminescence, further expanding the possibilities for gold nanoclusters. 

This study investigates the performance optimization at a molecular level, providing insights into the underlying processes that drive the positive property changes. It establishes a comprehensive protocol for obtaining high-performance gold nanoclusters and their composites, offering a general framework for future research endeavors.

Thesis available for public display 10 days prior to the defence at: 
https://aaltodoc.aalto.fi/doc_public/eonly/riiputus/

Electronic version of the doctoral theses is available in Aaltodoc.