In recent years, utilization of the abundant advantages of quantum physics, quantum dots, quantum wires, quantum wells, and nanocrystals has attracted considerable scientific attention in the field of nonvolatile memory. Nanocrystals are the driving element that have brought the nonvolatile flash memory technology to a distinguished height. However, new approaches are still required to strengthen this technology for future applications. This book details the methods of fabrication of nanocrystals and their application in baseline nonvolatile memory and emerging nonvolatile memory technologies. The chapters have been written by renowned experts of the field and will provide an in-depth understanding of these technologies. The book is a valuable tool for research and development sectors associated with electronics, semiconductors, nanotechnology, material sciences, solid state memories, and electronic devices.

In recent years, the abundant advantages of quantum physics, quantum dots, quantum wires, quantum wells, and nanocrystals in various applications have attracted considerable scientific attention in the field of nonvolatile memory (NVM). Nanocrystals are the driving elements that have helped nonvolatile flash memory technology reach its distinguished height, but new approaches are still needed to strengthen nanocrystal-based nonvolatile technology for future applications. This book presents comprehensive knowledge on nanocrystal fabrication methods and applications of nanocrystals in baseline NVM and emerging NVM technologies and the chapters are written by experts in the field from all over the globe. The book presents a detailed analysis on nanocrystal-based emerging devices by a high-level researcher in the field. It has a unique chapter especially dedicated to graphene-based flash memory devices, considering the importance of carbon allotropes in future applications. This updated edition covers emerging ferroelectric memory device, which is a technology for the future, and the chapter is contributed by the well-known Ferroelectric Memory Company, Germany. It includes information related to the applications of emerging memories in sensors and the chapter is contributed by Ajou University, South Korea. The book introduces a new chapter for emerging NVM technology in artificial intelligence and the chapter is contributed by University College London, UK. It guides the readers throughout with appropriate illustrations, excellent figures, and references in each chapter. It is a valuable tool for researchers and developers from the fields of electronics, semiconductors, nanotechnology, materials science, and solid-state memories.

Abstract: Recent trends of technology require reliable memory devices in terms of large capacity, bandwidth, and high performance along with low power consumption and cost to be compatible with scaling computing systems size. Currently, charge based memories such as dynamic random access memory (DRAM) face some issues in density scaling due to the high power needed to refresh the memory cell in order to keep its contents, which leads to a high production cost [1]. Non-volatile ferroelectric random access memory (NVFRAM) is considered a promising solution since it tackles the problem of high power consumption for refreshing cycles, being non-volatile, in addition to their nanosecond switching speed and capability of processing massive amounts of data similar to DRAM and flash memory[2]. Lead zirconate titanate or PZT (Pb(ZrxTi1−x)O3) capacitors are widely used in FRAM technology due to their excellent ferroelectric properties, however, they show degradation of polarization with increasing switching cycles owing to domain locking caused by the large amount of oxygen vacancies. Attempts to overcome the fatigue behavior of PZT were to use oxide electrodes instead of metallic ones, which adversely affect other properties of the memory cell- for instance leakage and data retention[3, 4]. Recently, doped binary crystals such as Ge doped- PbTe have been highlighted, due to their simple structure as well as ferroelectric properties, as a candidate for FRAM manufacturing[5]. The class of IV-VI semiconductor nanocrystals, among them germanium and lead tellurides, have been studied extensively over the past few decades due to their outstanding physical properties. They have a great potential for mid-infrared optoelectronic devices, such as photon detectors and laser emitters, in addition to energy conversion systems, such as solar cells, owing to their narrow band gap energy [6, 7]. Their high thermoelectric figure of merit makes them excellent for thermoelectric device applications. Moreover, their ability to undergo a structural ferroelectric phase transition, together with their reversible phase change from amorphous to crystalline state qualifies them for ferroelectric random access memory (FRAM) and phase change memory (PCM) applications. The present study is aiming to investigate the structural, optical, electrical, and ferroelectric properties of Pb50−xGexTe50 (x = 15, 20, 25, 30 at.%) nanocrystalline alloys, with a deep focus on increasing the ferroelectric phase transition temperature to overcome the first barrier of applying them to memory storage devices. This dissertation is composed of five chapters, the 1st chapter “Introduction” provides a brief explanation of the current challenges facing memory systems with a special focus on FRAM as a potential solution, along with presenting the main properties of IV- tellurides. The 2nd chapter “Literature Review” includes the previous work reported for the binary alloys PbTe and GeTe together with the ternary system Pb-Ge-Te. The 3rd chapter “Theoretical Background” introduces briefly the main theoretical models applied for crystalline semiconductors and the concept of ferroelectricity. The 4th chapter “Materials and Methods” collects the experimental techniques used in the current investigation. The 5th chapter “Results and Discussion” reports and analyzes the results of this experimental study, in addition to concluding the most important outcomes with proposing some future research scopes.

Nanocrystals research has been an area of significant interest lately, due to the wide variety of potential applications in semiconductor, optical and biomedical fields. This book consists of a collection of research work on nanocrystals processing and characterization of their structural, optical, electronic, magnetic and mechanical properties. Various methods for nanocrystals synthesis are discussed in the book. Size-dependent properties such as quantum confinement, superparamagnetism have been observed in semiconductor and magnetic nanoparticles. Nanocrystals incorporated into different material systems have proven to possess improved properties. A review of the exciting outcomes nanoparticles study has provided indicates further accomplishments in the near future.