2 Introduction, Motivation and Relevance

This is a brief introduction into the world of silicon nanocrystals, commonly abbreviated as Si NCs. In this introduction I will attempt to explain what these nanocrystals are and why they matter. In section 3, I’ll treat the reader to a broad overview of the physics involved. Starting with nothing more than electrons and photons you will experience sand, sun and solar panels, and learn how silicon nanocrystals are the ideal testbed for electron-photon interactions and why they’re interesting when thinking of solar power generation. After the introduction to the physics, it will be time for some experiments. After all, our knowledge is never complete. Section 4 discusses the setup used while section 5 will show what measurements were taken and what the results of those measurements are. In section 6 I will try to derive new useful information from these measurements. To conclude, section 7 will be all about the implications of the results and the implications of this kind of research in general.

Studying Si NCs can have two different motivations: learning about the world around us and learning how we can change the world for the better. Electron-photon interactions on the one hand and complex condensed matter systems on the other are both fundamental parts of the physical world, and therefore fundamentally interesting. Investigating Si NCs means investigating these elemental parts of physics and how this all interacts in macroscopic systems. The second motivation is a social and environmental one: energy is slowly becoming a real problem, not only of people and nations, but of the entire world. Shifting to renewable energy sources is perhaps the biggest mission mankind can have this century. Solar panels are one of the solutions for a greener planet and Si NCs have the potential to increase the efficiency and decrease the price of solar power generation.

Building these better solar panels means answering questions such as which semiconductors have the most efficient electron-photon interactions? What fractions of doping should be added to bulk materials? What shape should the band structure ideally have? Are there any other aspects which could increase efficiency, or perhaps affect the price of end products? The answers can help us find the best solar power generators, but also help us learn more about the interesting and complex physical systems that these crystals are.