SELF-ASSEMBLED SEMICONDUCTOR STRUCTURES - ELECTRONIC AND OPTOELECTRONIC PROPERTIES

Strained epitaxy has been shown to produce pyramidal-shaped semiconduc tor dot structures by single-step epitaxy, The very high density of th ese dots (approaching teradots per wafer) and their ever improving uni formity suggest that these features could have important applications in future microelectronics. Understanding the structural and electroni c properties of these quantum dots is therefore of great importance. I n this paper, we examine some of the physics controlling the performan ce of devices that could be made from such structures. The self-assemb led quantum dots are highly strained and we will examine the strain te nsor in these quantum dots using a valence force-field model. In this paper we will address the following issues, 1) What is the general nat ure of the strain tensor in self assembled quantum dots? 2) What are t he electron and hole spectra for InAs-GaAs quantum dots? 3) What are t he important intersubband radiative and nonradiative scattering proces ses in the self assembled quantum dots? In particular, we will discuss how the electron-phonon interactions are modified in the quantum dot structures. Consequences for uncooled intersubband devices such as las ers, detectors, and quantum transistors will be briefly discussed.