Preface

**Section 3 Nano-Structured Solar Cells - Organic and Thin Film**

Qiuping Huang, Xiang Hu, Zhengping Fu and Yalin Lu

Chapter 8 **Interface Engineering and Electrode Engineering for Organic**

Chapter 9 **Copper Indium Gallium Selenide Thin Film Solar Cells 183**

**Section 4 Nano-Structure Solar Cells - Perovskite Solar Cells 201**

Chapter 11 **Fabrication and Characterization of Element-Doped Perovskite**

Chapter 12 **Perovskite as Light Harvester: Prospects, Efficiency, Pitfalls**

Takeo Oku, Masahito Zushi, Kohei Suzuki, Yuya Ohishi, Taisuke

Serafettin Demic, Ahmet Nuri Ozcivan, Mustafa Can, Cebrail Ozbek

Chapter 10 **ZnO-Based Electron Transporting Layer for Perovskite**

Lung-Chien Chen and Zong-Liang Tseng

Matsumoto and Atsushi Suzuki

Chapter 13 **Recent Progresses in Perovskite Solar Cells 277**

**Solar Cells 135**

**VI** Contents

**Solar Cells 161**

**Solar Cells 203**

**Solar Cells 217**

**and Roadmap 245** Ruby Srivastava

and Merve Karakaya

Yang Tang

Chapter 7 **Plasmonic Thin Film Solar Cells 137**

Dazheng Chen and Chunfu Zhang

Recently, nanostructured solar cells have been identified as promising candidates for ach‐ ieving high conversion efficiency in solar or photovoltaics cells due to their small amount of light reflection losses. In relation to the reflection losses, when the period or pitch of a single nano-grating structure is less than the wavelength of the incident light, then the structure behaves like a homogeneous medium with an effective refractive index. Hence, these nanograting structures can provide gradual changes of the refractive index in several steps that confirm an excellent antireflective coating and light-trapping properties into the substrate compared to planar- or flat-type thin film substrates. There are different types of losses in solar cells that always reduce the conversion efficiency, but the light reflection loss is one of the most important factors that decreases the conversion efficiency of solar cells significant‐ ly. Therefore, the nano-grating structures (such as triangular or conical shaped) have a grad‐ ual change in refractive index that lead to a reduced amount of light reflection losses over a wide range of wavelengths and the angle of incidences.

This book presents a high-level technical overview of the emerging technologies on renewa‐ ble energy systems and the conversion efficiency improvement of solar cells. It is intended as an introduction to the field for solar cells or renewable energy and professional or indus‐ trial engineers as well as the higher degree research students, research academics and de‐ sign engineers. Although it is intended for professionals who already have some technical background, it is nevertheless relevant to anyone wishing to understand renewable or solar energy systems and the improvement of its conversion efficiency.

The nano-grating structures have a gradual change in refractive index which acts as a multi‐ layer antireflective coating leading to reduced light reflection losses over broadband ranges of wavelength and angle of incidence. The antireflective coating is an optical coating which is applied to the surface of lenses or any optical devices to reduce the light reflection losses. This coating assists in light-trapping capturing capacity or improves the conversion efficien‐ cy of optical devices, such as lenses or solar cells. The multilayer antireflective coatings can reduce the light reflection losses and increase the conversion efficiency of nanostructured solar cells.

#### **Organisation of the book**

The authors with whom I have had the pleasure to collaborate have written chapters that report recent developments in nanostructured solar cells and renewable energy. They cover a number of themes which include the general concepts of solar cells or renewable energy; devices used for solar cells, such as nano-structures and nano-gratings; renewable energy systems; and related topics as described above. No book of the current length can encom‐ pass the full scope of the subject, but I am pleased at the range of topics that we have been able to include in this book.

In this book, the chapters have been grouped in sections according to the following themes: Nanostructured Solar Cells - General Concepts; Nanostructured Solar Cells - Junction-type Solar Cells, such as single junction and heterojunctions; Nanostructured Solar Cells - Organ‐ ic and Thin Film Solar Cells, such as organic, thin film and plasmonic-type solar cells; and Nanostructured Solar Cells - Perovskite Solar Cells, such as progresses and the fabrication of perovskite solar cells. These categorisations of parts are not fully perfect because some of the chapters are mixed or overlapped, i.e. like an interdisciplinary research topic. However, all the chapters are within an easily identifiable subject boundary that is a positive sign of the indicators of scientific progress in nanostructured solar cells.

I acknowledge all the contributed authors for their support in this book chapters from differ‐ ent organisations (universities and industries).

I acknowledge Associate Professor Tony Ahfock, Head of School, School of Mechanical and Electrical Engineering, University of Southern Queensland, Toowoomba, Queensland, Aus‐ tralia, and John Curtin Distinguished Professor Syed Islam, Department of Electrical and Computer Engineering, Curtin University, Perth, Australia, for their continuous support and encouragement to complete this task. I also acknowledge Dr Mainul Islam, University of Southern Queensland, Toowoomba, Queensland, Australia, for his continuous support and encouragement to complete this book.

I am very much grateful to Ms. Iva Simcic and Ms. Ana Pantar, book publishing process managers at InTech, for their prompt responses to my queries in regard to completing this book. I wish all of my collaborators every success in their future research activities.

Foremost' I would like to thank my wife Mrs. Varoti Das, son Nishikanta Das and daughter Nandita Das for their strong patience' understanding, continuous encouragement and sup‐ port to complete this book.

> **Dr. Narottam Das** School of Mechanical and Electrical Engineering University of Southern Queensland, Toowoomba, Queensland, Australia

> > Department of Electrical and Computer Engineering Curtin University, Perth, WA, Australia

**Nano-Structured Solar Cells - General Concepts**

pass the full scope of the subject, but I am pleased at the range of topics that we have been

In this book, the chapters have been grouped in sections according to the following themes: Nanostructured Solar Cells - General Concepts; Nanostructured Solar Cells - Junction-type Solar Cells, such as single junction and heterojunctions; Nanostructured Solar Cells - Organ‐ ic and Thin Film Solar Cells, such as organic, thin film and plasmonic-type solar cells; and Nanostructured Solar Cells - Perovskite Solar Cells, such as progresses and the fabrication of perovskite solar cells. These categorisations of parts are not fully perfect because some of the chapters are mixed or overlapped, i.e. like an interdisciplinary research topic. However, all the chapters are within an easily identifiable subject boundary that is a positive sign of the

I acknowledge all the contributed authors for their support in this book chapters from differ‐

I acknowledge Associate Professor Tony Ahfock, Head of School, School of Mechanical and Electrical Engineering, University of Southern Queensland, Toowoomba, Queensland, Aus‐ tralia, and John Curtin Distinguished Professor Syed Islam, Department of Electrical and Computer Engineering, Curtin University, Perth, Australia, for their continuous support and encouragement to complete this task. I also acknowledge Dr Mainul Islam, University of Southern Queensland, Toowoomba, Queensland, Australia, for his continuous support

I am very much grateful to Ms. Iva Simcic and Ms. Ana Pantar, book publishing process managers at InTech, for their prompt responses to my queries in regard to completing this

Foremost' I would like to thank my wife Mrs. Varoti Das, son Nishikanta Das and daughter Nandita Das for their strong patience' understanding, continuous encouragement and sup‐

**Dr. Narottam Das**

School of Mechanical and Electrical Engineering

Curtin University, Perth, WA, Australia

Department of Electrical and Computer Engineering

University of Southern Queensland, Toowoomba, Queensland, Australia

book. I wish all of my collaborators every success in their future research activities.

indicators of scientific progress in nanostructured solar cells.

ent organisations (universities and industries).

and encouragement to complete this book.

port to complete this book.

able to include in this book.

VIII Preface
