Francis Chi-Chung Ling, Shengqiang Zhou and Andrej Kuznetsov
Chapter 2 Defect Physics in 2D Nanomaterials Explored by TEM/STM
Jinhua Hong, Maohai Xie and Chuanhong Jin
Chapter 3 Defects in Perovskites for Solar Cells and LEDs
F. Biccari, N. Falsini, M. Bruzzi, F. Gabelloni, N. Calisi and A. Vinattieri
Chapter 4 Color Centers in Wide-Gap Semiconductors for Quantum Technology
Y. Yamazaki, S. Onoda and T. Ohshima
Chapter 5 Point Defects in InN
Xinqiang Wang and Huapeng Liu
Chapter 6 Dopants and Impurity-Induced Defects in ZnO
M. Azizar Rahman, Matthew R. Phillips and Cuong Ton-That
Chapter 7 Ferromagnetism in B2-Ordered Alloys Induced via Lattice Defects
Rantej Bali
Chapter 8 Defects-Induced Magnetism in SiC
Yu Liu
Chapter 9 Ferromagnetism in ZnO-based Materials and Its Applications
Muhammad Younas
CHAPTER 1
Studying Properties of Defects
FRANCIS CHI-CHUNG LING∗,§, SHENGQIANG ZHOU†,¶ and ANDREJ KUZNETSOV‡,||
∗Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, China
†Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstrasse 400, 01328 Dresden, Germany
‡Department of Physics, Center for Materials Science and Nanotechnology, University of Oslo, Sem Saelands vei 24, 0316 Oslo, Norway
1. Introduction
Functional materials cover a wide range of materials — such as metals, semiconductors, polymers, oxides, etc. — demonstrating suitable electrical, optical and magnetic properties to be used for different applications. Indeed, such materials exhibit a number of physical phenomena including ferroelectricity, piezoelectricity, superconductivity, magnetism, dielectric and optoelectronic properties, etc. As a result, functional materials find a variety of applications in sensors, lasers, displays, printable electronics, solid-state lighting, energy harvesting and storage, catalysis, etc. The research on functional materials has attracted much of attention in recent years, and its advancement nutrifies the development in such cross-disciplinary branches as life-science, energy, and information technologies.
Making use of the materials for each specific function requires a full control over electrical, optical and/or magnetic properties, which are crucially determined by the presence of defects in the materials. Such defects may be introduced intentionally or unintentionally during the materials synthesis and/or processing steps. Notably, despite of the importance of defects, the understanding of defects in many materials and the relevant applications are far from being complete.
Admittedly, there is a big number of very good reviews and books devoted to defects studies keeping published along the decades, confirming strong and renewing interest to this subject. For example, within the last two decades, excellent reviews on defect identification and defect properties were published by Agullo-Lopez [1], Kuzmany [2], Stavola [3], Stavola [4], McCluskey [5], Schroder [6], Janotti and Van de Walle [7], Grundmann [8], Pajot [9], Pajot [10], Vines and Kuznetsov [11], Freysoldt et al. [12], Stavola and Fowler [13], McCluskey and Haller [14], and Tuomisto [15] — to name just a part of the literature.
Complementing the existing literature, this chapter introduces a selection of electrical, optical, structural, and magnetic spectroscopic methods for defects studies frequently used in functional materials, including those further discussed in the subsequent chapters of the present book. Particular attention is given to the topics of the CV and Hall measurements, deep level transient spectroscopy (DLTS), luminescence spectroscopy, positron annihilation spectroscopy (PAS), and electron spin resonance (ESR); also listing a number of relevant references for further reading.
2. Electrical Characterizations
The electrical characterizations of materials is of paramount importance for a wide range of applications as being comprehensively discussed for example by Look [16], Schroder [6], Grundmann [8],
