ABSTRACT

The microelectronics revolution has given rise to the concept that smaller device dimensions provide enhanced performance with an increased number of components in a circuit, higher operating speeds, and lower power consumption at a reduced cost [1]. This research has led to the vast range of semiconductor electronic and photonic devices and phenomena with which we are familiar today, such as high electron mobility and complementary metal oxide eld effect transistors (FETs), lasers, light-emitting diodes (LEDs), and quantum Hall effects. Their benecial

3.1 Introduction .................................................................................................... 31 3.2 Distinguishing Feature of NWs over the Bulk ............................................... 32 3.3 Growth Mechanism of NWs ........................................................................... 33 3.4 Background of Sb-Based Binary NWs and GaAsSb NWs .............................34 3.5 Structural and Optical Characteristics of MBE Grown GaAsSb-Segmented NWs ............................................................................... 35

3.5.1 Experimental Procedure .....................................................................36 3.5.2 Scanning Electron Microscopy ..........................................................36 3.5.3 Transmission Electron Microscopy .................................................... 38 3.5.4 Photoluminescence ............................................................................. 41 3.5.5 Raman Spectroscopy .......................................................................... 45

3.6 Conclusions ..................................................................................................... 47 Acknowledgments .................................................................................................... 47 References ................................................................................................................48

impact on society in general and the military in particular thus provides motivation for further downscaling to nanometer dimensions. It has been suggested that the new phenomena associated with novel nanoscale materials and devices offer the opportunity for engineering unique material properties and bottom-up assembly and to serve as the building blocks for the next generation of integrated nanosystems. In nanometer-scaled structures, radial and longitudinal quantum connement in conjunction may also provide the ability to realize the control of electronic, optical, and magnetic properties of the materials in functional devices. Further, the relaxation of the lattice mismatch constraints, a major impediment encountered in thin-lm heterostructures, provides the exibility to integrate nanoscale heterostructures of a wide range of materials with engineered features that could lead to a new class of multifunctional devices, having high impact on the optoelectronic, nanoelectronic, and energy applications.