Photoluminescence of Silicon Nanocrystals:
The Origin of Different Components.

A Bachelor’s Thesis by Brent Huisman
brenthuisman@gmail.com

Supervisor and Reviewer: Dolf Timmerman
Second Reviewer: Tom Gregorkiewicz


July 28, 2010

Download PDF - Table of Contents

Abstract

In this project the photoluminescence (PL) of silicon nanocrystals is studied. It is found that the PL spectrum consists of a band-to-band component and a defect related component. A linear dependence between the excitation energy and the intensity of the defect related component is found. The fraction of excited crystals was kept constant by altering the laser beam intensity. The defect related energy level is probably introduced by oxygen bonds at the edge of the nanocrystal, and possibly lies inside the conduction band. A systematic method of measurement is proposed for future characterization of silicon nanocrystals.

PIC
University of Amsterdam, Faculty of Science, Van der Waals-Zeeman Institute

1 Popular Dutch Summary
Table of Contents
2 Introduction, Motivation and Relevance
3 Physics
 3.1 Electrons and Photons
 3.2 The Indirect Bandgap and Solar Panels
 3.3 Silicon Nanocrystals
 3.4 Decay and Quantum Cutting
 3.5 The Mechanisms for Quantum Cutting
 3.6 Measuring Quantum Cutting
 3.7 Efficiency
 3.8 From Theory to Experiment
4 Setup
 4.1 Generating Input
 4.2 The Sample
 4.3 Capturing Output
5 Experiment and Results
 5.1 Calibration Curves and Software
 5.2 Photoluminescence
 5.3 Time Resolved Measurements
 5.4 Higher Energies or More Power?
6 Interpretation
 6.1 What can be improved?
7 Further Thoughts
8 Bibliography