%0 Journal Article
%T Influence of Oscillatory Impurity Potential and Concurrent Gasping of Impurity Spread on Excitation Profile of Doped Quantum Dots
%A Suvajit Pal
%A Manas Ghosh
%J Journal of Materials
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/795450
%X Excitation in quantum dots is an important phenomenon. Realizing the importance we investigate the excitation behavior of a repulsive impurity-doped quantum dot induced by simultaneous oscillations of impurity potential and spatial stretch of impurity domain. The impurity potential has been assumed to have a Gaussian nature. The ratio of two oscillations ( ) has been exploited to understand the nature of excitation rate. Indeed it has been found that the said ratio could fabricate the excitation in a remarkable way. The present study also indicates attainment of stabilization in the excitation rate as soon as ¦Ç surpasses a threshold value regardless of the dopant location. However, within the stabilization zone we also observe maximization in the excitation rate at some typical location of dopant incorporation. The critical analysis of pertinent impurity parameters provides important perception about the physics behind the excitation process. 1. Introduction Nowadays we frequently encounter a plethora of theoretical and experimental researches on impurity states in low-dimensional heterostructures [1]. The advent of so-called low-dimensional structures such as quantum dots (QD) has considerably accelerated the technology-driven demand of miniaturization of semiconductor devices. The quantized properties of quantum dots doped with impurity have generated new perspectives and subtleties in the field of applied physics. This happens because of the interplay between various confinement sources with impurity potentials [2]. Out of various kinds of investigations on impurity doping, control of optoelectronic properties emerges as the central theme [3¨C15]. Naturally, we find a vast literature comprising of good theoretical studies on impurity states [16¨C21]. Added to this, there are also some excellent experimental works which include the mechanism and control of dopant incorporation [22, 23]. Driven by the emergence of novel experimental and theoretical techniques along with the existing ones, the research on carrier dynamics in nanodevices has become a ubiquitous field. The internal transitions between impurity-induced states in a QD led to research on carrier dynamics [8, 24]. These transitions depend on the spatial restriction imposed by the impurity. A minute survey of the above dynamical features directs us to explore excitation of electrons strongly confined in QD¡¯s. Analysis on this aspect deems importance since it offers us model systems for use in optoelectronic devices and as lasers. In connection with the technological applications, excitation in
%U http://www.hindawi.com/journals/jma/2013/795450/