Functional materials in New Millennium Systems PDF

INTRODUCTION

The development of activity on III-V semiconductors started to grow rapidly following the appearance, in 1952,of a landmark paper by H. Welker. Subsequently, the III-V family has provided a very rich and versatile environment where many novel aspects of condensed matter physics have been investigated and proven for the first time. A wide range of electronic and opto-electronic devices, for which silicon holds no competition, has been developed alongside. Central to success has been the ability to engineer the band structure of these semiconductors in subtle ways, through alloying, through grown-in variations of alloy composition on a scale comparable to an electronic de Broglie wavelength (,..,.10nm)or less, through built-in strain, and more recently through forms of self organisation which can be induced during growth.

The long neglected wide band-gap III-V nitride compounds, and their alloys, have now become the focus of considerable activity, promising coherent light sources in the blue region and beyond and bipolar and unipolar transistors operating at high power levels. Blue edge-emitting lasers utilising an InGaN multiple quantum well active region have recently been demonstrated.

This paper reviews some of the major advances made since 1952and outlines the direction in which future research in Ill-V semiconductors is moving.

Edited by: M.J. Kelly