Preface

*Post-Transition Metals* contains recent research on the preparation, characterization, and potential applications of post-transition metals such as gallium, indium, tin, thallium, lead, and bismuth, among others. Interest in the chemistry of posttransition elements has increased significantly in the last two decades. In particular, research on the metals of Group 13 has led to the synthesis and application of some very novel molecules, with implications for organometallic synthesis and new materials development for chemical, biological, medical, and environmental uses. This book also discusses new facts, developments, and applications in the context of more general patterns of physical, structural, morphological, and optical behaviors. Particular attention is paid to the main growth areas, including the chemistry of lower formal oxidation states, cluster chemistry, device fabrication, the investigation of solid oxides and hydroxides, advances in the formation of hybrids with II–V and related compounds, the chemical significance of Group 13 metal complexes, and the growing importance of the metals and their compounds in the mediation of inorganic reactions.

In Chapter 1, Prof. Jana et al. discuss indium oxide-based nanomaterials and their fabrication strategies, properties, applications, challenges, and future prospects. The authors highlight synthesis strategies for indium oxide-based bulk nanomaterials with variable morphologies starting from spherical nanoparticles to nanorods, nanowires, nanoneedles, nanopencils, nanopushpins, and more. In addition, the chapter examines thin-film deposition and periodic 1-dimensional/2-dimensional surface texturing techniques for indium oxide-based nanostructured thin films with regard to their functional properties and applications. The chapter also includes a state-of-the-art survey on fabrication strategies and recent advancements in the properties of indium oxide-based nanomaterials with their different areas of applications.

In Chapter 2, Prof. Revaprasadu et al. report on indium chalcogenide nanomaterials, which are at the forefront of recent technological advancements. There has been an increasing trend in the exploitation of indium chalcogenides in various applications ranging from water-splitting reactions in renewable energy to degradation of dyes in environmental rehabilitation. This trend is attributed to the interesting and unique properties of indium chalcogenide nanomaterials, which can be easily tuned via engineering of particle size, shape, and morphology. In this chapter, the authors outline the preferred attributes of indium chalcogenide nanomaterials that are deemed suitable for certain applications. Furthermore, they explore recent reaction protocols that have been reported to yield good quality indium chalcogenide nanomaterials of multinary configurations (e.g., binary and ternary compounds). Finally, the authors address the urgent need for alternative synthesis routes, such as the use of low-temperature decomposing single-source molecular precursors, to be improved and incorporated in the fabrication of functional nanodevices.

In Chapter 3, Dr. Svirsky et al. discuss the ionic state of indium in perchlorate solutions as well as the physicochemical properties of indium perchlorate. In perchlorate solutions, indium (III) cations attach a larger number of layers of water as well as

**II**

**Chapter 8 129**

**Chapter 9 169**

GaAs Compounds Heteroepitaxy on Silicon for Opto and Nano Electronic

*by Mickael Martin, Thierry Baron, Yann Bogumulowicz, Huiwen Deng,* 

IMPATT Diodes Based on GaAs for Millimeter Wave Applications

*Keshuang Li, Mingchu Tang and Huiyun Liu*

*by Janmejaya Pradhan and Satya Ranjan Pattanaik*

Applications

with Reference to Si

varying degrees, affect its state and through it, the action spreads further to the property and the boundary medium Thus, this causes either a de-structuring effect or a change in the state of chemical bonds of chlorate ions in concentrated solutions. Thus, the chlorate ion, being structure-forming and exhibiting a proto-acceptor ability, in solutions of group III perchlorates forms exclusively solvate-separated ion pairs due to the high enthalpy of hydration of the corresponding metal cations.

In Chapter 4, Associate Prof. Benabderrahmane investigates the effect of indium oxide on the properties of indium particles, which are used as silicon nanowire catalysts. The author examines the elaboration of indium particles by different annealing processes such as rapid thermal annealing as well as conventional processes. The elaborated particles are dedicated for use as catalysts for growing silicon nanowires growth via the vapor–liquid–solid process. After conventional annealing, the indium layer is broken up into elongated and inhomogeneous islands of micrometric sizes. The annealing conditions influence the catalyst morphology and, consequently, grow silicon nanowires.

In Chapter 5, Prof. Tabbakh et al. report on the elastic, optical, structural, and transport properties of gallium arsenide (GaAs). These excellent properties have led to the production of new and unique devices like high-efficiency light emitters, light sensors, and high-speed switching devices. GaAs is considered an outstanding member of the III–V semiconductor family. It has many exceptional features, especially for use in opto-electronic and micro-electronic devices.

In Chapter 6, Mr. Rouf et al. carry out a comparative analysis of the nanoindentation technique. Nano-indentation is a dynamic perceptible method for attaining mechanical properties from limited content. In delicately regulated tests in which the acceptance of the elastic contact analysis is met, the accuracy of a few percentage points is smoothly obtainable for indentations as micro as 10 nm. Specialists must be constantly aware of the holdings of variations from these suppositions on nano-indentation results. An exact evaluation for load, displacement, and machine concurrence is required, as is an effective rational sketch of the shape of the tip and a configuration devised to reduce the consequences of thermal drift and plasticity. Nanoindentation uses an indirect method of determining the contact area, as the depth of penetration is measured in nanometers, while in conventional indentation the area in contact is measured by elementary measurement of the residual area after the indenter is removed from the specimen. Dynamic hardness is the best result of dynamic indentation, which can be expressed as the ratio of energy consumed during a rapid indentation to the volume of indentation. The parameters taken into consideration are indentation depth, contact force, contact area, and mean contact pressure.

In Chapter 7, Prof. Yamaguchi describes a solar cell developed with GaAs material. The author reviews the progress in III–V compound single-junction solar cells such as Gallium Arsenide (GaAs), Indium Phosphide (InP), Aluminium gallium arsenide (AlGaAs), and Indium Gallium phosphide (InGaP) cells. Results show that GaAs solar cells have 29.1% under the sun, which is the highest ever reported for single-junction solar cells. In addition, the author presents analytical results for non-radiative recombination and resistance losses in III–V compound solar cells by considering fundamentals for major losses in III–V compound materials and solar cells. Because the limiting efficiency of single-junction solar cells is 30%–32%, multi-junction solar cells have been developed. GaP/GaAs–based 3-junction solar cells are widely used in this space. Additionally, the III–V compound solar cells have

**V**

contributed as space and concentrator solar cells and are expected to be used in large-scale electric power systems and solar cell-powered electric vehicles.

In Chapter 8, Ph.D. Baron et al. report on opto- and nanoelectronic applications with GaAs compounds heteroepitaxy on silicon. The authors show how to overcome the different challenges associated with heteroepitaxy and integration of III-As onto a silicon platform. They present solutions to get rid of antiphase domains for GaAs grown on exact Si(100). To reduce the threading dislocations density, efficient ways based on either insertion of InGaAs/GaAs multilayers defect filter layers or selective epitaxy in cavities are implemented. All these solutions allow for the fabrication of electrically pumped laser structures based on InAs quantum dots active region,

Finally, in the last chapter, Dr. Pradhan et al. investigate IMPact ionization Avalanche Transit-Time (IMPATT) diodes based on GaAs for millimeter-wave applications with reference to silicon. The chapter presents DDR IMPATTs based on GaAs designed to operate at mm-wave window frequencies of 94, 140, and 220GHz. Both the DC and small-signal performances of these devices are investigated by using a small signal simulation technique developed by the authors. The efficiency, output power, and power density of a GaAs IMPATT are greater than that of a Si IMPATT. Results show that the DDR IMPATTs based on GaAs are most suitable for generating radio frequency power with maximum conversion efficiency up to 220GHz. This chapter looks at the benefits of GaAs in power electronics applications, reviews the current state of the art, and shows GaAs is a strong and feasible candidate for IMPATTs. It is also well known that at a given frequency the microwave and mm-wave power output of an IMPATT diode are proportional to the square of the product of the semiconductor critical field and carrier saturation velocity. For mm-wave frequencies greater than 94GHz, a GaAs semiconductor is the best choice for

**Dr. Mohammed Muzibur Rahman**

and Department of Chemistry,

King Abdulaziz University, Jeddah, Saudi Arabia

King Abdulaziz University, Kingdom of Saudi Arabia

Faculty of Science,

**Thamer Tabbakh** Assistant Professor,

Saudi Arabia

Center of Excellence for Advanced Materials Research

King Abdulaziz City for Science and Technology,

**Dr. Abdullah Mohamed Asiri, Dr. Anish Khan and Dr. Inamuddin**

which is required for photonic and sensing applications.

fabricating a DDR IMPATT device.

contributed as space and concentrator solar cells and are expected to be used in large-scale electric power systems and solar cell-powered electric vehicles.

In Chapter 8, Ph.D. Baron et al. report on opto- and nanoelectronic applications with GaAs compounds heteroepitaxy on silicon. The authors show how to overcome the different challenges associated with heteroepitaxy and integration of III-As onto a silicon platform. They present solutions to get rid of antiphase domains for GaAs grown on exact Si(100). To reduce the threading dislocations density, efficient ways based on either insertion of InGaAs/GaAs multilayers defect filter layers or selective epitaxy in cavities are implemented. All these solutions allow for the fabrication of electrically pumped laser structures based on InAs quantum dots active region, which is required for photonic and sensing applications.

Finally, in the last chapter, Dr. Pradhan et al. investigate IMPact ionization Avalanche Transit-Time (IMPATT) diodes based on GaAs for millimeter-wave applications with reference to silicon. The chapter presents DDR IMPATTs based on GaAs designed to operate at mm-wave window frequencies of 94, 140, and 220GHz. Both the DC and small-signal performances of these devices are investigated by using a small signal simulation technique developed by the authors. The efficiency, output power, and power density of a GaAs IMPATT are greater than that of a Si IMPATT. Results show that the DDR IMPATTs based on GaAs are most suitable for generating radio frequency power with maximum conversion efficiency up to 220GHz. This chapter looks at the benefits of GaAs in power electronics applications, reviews the current state of the art, and shows GaAs is a strong and feasible candidate for IMPATTs. It is also well known that at a given frequency the microwave and mm-wave power output of an IMPATT diode are proportional to the square of the product of the semiconductor critical field and carrier saturation velocity. For mm-wave frequencies greater than 94GHz, a GaAs semiconductor is the best choice for fabricating a DDR IMPATT device.
