Topics and Questions on Concepts

Why optical (photoabsorption and PL) properties of Si02 and Ge02 nanomaterials can dramatically differ from the properties of bulk silica 

What is the role of point defects in optical properties of silica and germania nanomaterials  

Discuss the structure and composition of the most typical point defects in Si02 and Ge02. 

Why the absorption and luminescence spectra of Si02 and Ge02 nanomaterials can be drastically different from one another both in terms of maximum wavelength and band shape What is the origin of large Stokes shifts in these materials  

Why the properties of point defects in silica and germania can be simulated using quantum chemical calculations of model clusters of a finite size Describe the requirements for model clusters to be suitable for such simulations. 

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