Introduction of Nanodevices

UNIT - V

CHAPTER 5

NANO DEVICES

Introduction - Electron density in bulk material - Size dependence of Fermi Energy - Quantum Confinement - Quantum Structures -  Density of states Density of states in bulk material (or) density of states in three dimension - Density of states in quantum well (or) density of states in two dimension - Density of states in quantum wire (or) Density of state in one dimension - Density of states in quantum dot (or) Density of state in Zero dimension - Band gap of Nano materials - Tunneling - Coulomb blockade effect (Optional) - Single electron phenomena and single electron transistor - Single electron phenomena Single electron transistor (SET) - Electrical behavior of an ideal SET (optional) Quantum dot Laser (QD Laser) - Conductivity of metallic nano wires Ballistic Transport - Quantum Resistance and quantum conductance - Carbon Nanotubes (CNTS) Types of carbon Nanotubes - Properties of Carbon Nanotubes Applications of Carbon Nanotubes.

INTRODUCTION

Nanoscience and nano technology refer to the control and manipulation of matter at nanometer dimensions.

Chemically synthesized nanostructures have been used at various stages of civilization.

Metallic gold, when divided into fine particles from sizes of 10-500 nm particles, can be suspended in water.

In the Indian medical system called Ayurveda, gold is used in several preparations. One popular preparation is called 'Saraswatharishtam prescribed for memorry enhancement. According to Robert Floyd Curl, Jr., Noble prize winner in chemistry in 1996, Indian Craftsmen used nanotechnology in wootz steel as well as in paintings. More specifically Carbon nanotubes, first announced by Russian Scientists in 1952, was found in the sword of Tipu sultan as well as in Ajanta paintings.

The current growth of technology suggests that reductions are needed in the dimensions of devices and active materials. The pentium of 1993, used a 800nm technology which consists of 3,100,000 transistors per square inch on Integrated circuits. The pentium 4 "prescott" of 2004, used a 90nm technology which consists of 125,000,000 transistors per square inch on integrated circuits. Extensive Research is going on to reduce the dimension further.

Nanoelectronics refer to the use of nanotechnology in electronic components. Nanoelectronics are sometimes considered as disruptive technology because present candidates are significantly different from traditional transistors. In this chapter, we will discuss about the electronic propertics of bulk materials, quantum well, quantum wire and quantum dots, single electron transitor, Spintronics, Carbon nano tubes.