This is an excellent book on devices based on graphene and other two-dimensional (2D) materials, such as MoS2, including their physics and applications. The book contains three chapters covering the fabrication and characterization of 2D materials, transistors, and other nanodevices and acts as a user guide for researchers working with atomically thin materials in applied physics.
Chapter 1 consists of four parts discussing physics and applications of graphene-based nanostructures and their applications in optoelectronics and sensors. The chapter starts with bondings between atomic orbitals, interaction between carbon atoms, their allowed energy states, and the density of charge carriers derived using a quantum mechanical approach. Functionality of graphene-based field-effect transistors (FETs), diodes, detectors and receivers, sensors, and photonic devices are discussed. Allowed energy states, density of states, carrier density, mobility, and other physics parameters in these nanodevices are derived by employing the tight-binding approximation, Drude model, and Dirac spinor method. Gate voltage-dependent current–voltage (I–V) characteristics of graphene FETs are well explained. Conduction mechanisms, current density equations, and I–V characteristics of various types of graphene-based diodes are also covered.
Chapter 2 deals with various growth process mechanisms of 2D materials, such as chemical vapor deposition, physical vapor deposition, bottom-up approach, and top-down method. Growth of transition metal dichalcogenides (TMDs), semimetal chalcogenides, and 2D alloys are covered. Typical mechanical properties and optical properties are tabulated with the help of literature. Band diagrams of several TMDs, thickness-dependent band structures, band structures of bilayer-monolayer TMDs, vertical heterostructures, photoexcited heterostructures, and van der Waals heterostructures are discussed.
Electronic devices such as transistors, diodes, and optoelectronic devices based on atomically thin materials are covered in chapter 3. Schottky barriers at monolayers, unwanted tunnel currents, mobility, and other electrical properties in different device structures are briefly described. Highly bendable MoS2 FETs, dual-gate MoS2 FETs, radio-frequency MoS2 transistors, and self-aligned FETs and their I–V characteristics with typical working conditions are described. Electronic injection and band diagrams of graphene-based heterostructures, MoS2/WSe2, black phosphorous/SnSe2, and nonvolatile memory based on MoS2/graphene heterostructures are discussed. Absorption spectrum of MoS2 monolayers and exciton binding energy of some TMDs are briefly described. Graphene/MoS2 photodetectors and their quantum efficiency, expression for gain, and the functionality of such photo-devices are clarified. In2Se3 and WSe2-based photodetectors and the world’s thinnest lens made with a MoS2 layer are also mentioned.
This is an outstanding book covering a range of nanodevices based on 2D materials. Fundamental properties and fabrication methods of recent 2D materials are well covered. It is targeted toward researchers rather than students. There are no solved problems or homework problems. Up-to-date references are given at the end of each chapter. The written material is augmented with many excellent figures, diagrams, illustrations, and images. I strongly recommend this book to researchers interested in device fabrication based on 2D materials.
Reviewer: K. Kamala Bharathi is an assistant professor at the SRM Institute of Science and Technology, India.