Controllable Growth and Unexpected Effects of Ge Nanocrystals

Abstract

Being a smart material, nanoscale semiconductors have displayed properties unique to their small size in comparison with the normal bulk materials owing to the effect of quantum confinement on electronic and optical properties. There are potential applications in novel photonic devices. 1À4 For example, when the diameter of a Si nanowire is reduced to the order of magnitude of the electron's de Broglie wavelength, visible photoluminescence may be produced. Much attention has been paid to the investigation of group IV semiconductor nanocrystals, such as nanowires/nanorods and nanotubes, due to their contribution to the understanding of fundamental principles in mesoscopic physics, as well as the potential applications in optoelectronic devices. 5À7 Due to its advantageous semiconducting, optical, and chemical properties, germanium has many important fields of application, such as infrared detector devices, optical lens systems for infrared, fiber optics, electronic devices, and solar cells. 8 For example, Ge wafers have been used in the manufacture of solar cells, though there are other emerging applications which are starting to gather momentum, such as light-emitting diodes, photodetectors, and high electron mobility transistors, etc. 9 In recent years, semiconductor Ge and composites have also attracted much attention due to their broad application in many fields, such as microelectronic devices, one-dimensional quantum transistors, and light-emitting diodes. 10À12 Considerable effort has been focused on the

Retracted Article: Insights from investigations of tin dioxide and its composites: electron-beam irradiation, fractal assessment, and mechanism

“…[1][2][3][4] These oxide materials have two unique structural features: mixed cation valences and an adjustable oxygen deficiency, which are the bases for creating and tuning many novel material properties, from chemical to physical. [5][6][7] Developing new materials with excellent performances depends not only on the multi-components but also on their micro/nanostructures. Multi-components and micro/nanostructures are the key issues to realize multifunctional materials.…”

Retracted Article: Multifunctional tin dioxide materials: advances in preparation strategies, microstructure, and performance

“…It can be seen that the fractal patterns exhibit an open and loose structure with increasing substrate temperature. The average size and fractal dimension (D) of the fractal clusters for four thin films were estimated by measurement on the fractal regions and using the conventional box-counting method, [35][36][37] respectively, which were found to be about 0.307 mm ( On the basis of experimental observations, the formation process of SnO 2 nanocrystals and fractal clusters could be reasonably described by a novel model proposed by us. 33 It was separated into eight steps, which is illustrated in detail in (ii) production of the high-temperature and highpressure SnO 2 plasma at the solid-liquid interface quickly after the interaction between the pulsed laser and the SnO 2 target; (iii) subsequent expansion of the high-temperature and high-pressure SnO 2 plasma leading to cooling of the SnO 2 plumes.…”

“…It can be seen that the fractal patterns exhibit an open and loose structure with increasing substrate temperature. The average size and fractal dimension (D) of the fractal clusters for four thin films were estimated by measurement on the fractal regions and using the conventional box-counting method, [35][36][37] respectively, which were found to be about 0.307 mm (Fig. 3A) with D = 1.896, 0.906 mm (Fig.…”

Morphologies and Nonlinear Optical Properties of Fractal Ge Nanocrystals Embedded in Pd Matrix

“…With the development and progress of science and technology, semiconductor materials encompass a burgeoning and fascinating area of materials research that has significant technological implications . In group IV semiconductors, germanium (Ge) and silicon (Si) belong to a class of unique materials with widespread technological applications because of their valuable semiconducting, mechanical, electrical, and optical properties in the fields of macro/mesoscopic materials and micro/nanodevices. , These semiconductors are indispensable for many applications, particularly for the electronics and photovoltaic industry. − Semiconductors such as Ge and Si micro/nanoclusters are of fundamental importance to the development of smart and functional materials, devices, and systems. − An integrated device or component for the semiconductor industry is highly desirable for versatile advanced applications. Notwithstanding the fact that semiconductor Ge has been applied to many areas, its use is not as extensive as that of Si and nebulous domains in our understanding of its precise technical functions still remain.…”

“…1 In group IV semiconductors, germanium (Ge) and silicon (Si) belong to a class of unique materials with widespread technological applications because of their valuable semiconducting, mechanical, electrical, and optical properties in the fields of macro/mesoscopic materials and micro/nanodevices. 2,3 These semiconductors are indispensable for many applications, particularly for the electronics and photovoltaic industry. 4−6 Semiconductors such as Ge and Si micro/ nanoclusters are of fundamental importance to the development of smart and functional materials, devices, and systems.…”