In recent years, progress in nanotechnology has allowed manufacturing of ultra small systems in the areas of electronics and opto-electronics with a high-precision capability of controlling the size and shape. Quantum dots (QD) are typical examples of nanosystems where the electrons are confined in all the 3-dimensions. These quasi-zero-dimensional systems show exotic electronic behaviors typical of the atom like discrete density of states (DOS) of the carriers. QDs could incorporate dopant impurities as a crucial ingredient for their proper functioning. The great interest for understanding the properties of these impurity containing systems comes from the fact that the impurity modifies the energy levels of the materials and in turn affects their electronic and optical properties. So these systems have potential use in electro-optical devices. In this book we explore the excitation kinetics of a repulsive impurity doped quantum dot owing to the time-variation of several impurity parameters e.g. impurity coordinate, impurity domain, and impurity potential. The investigation reveals the sensitivity of the interplay between the above parameters that ultimately shapes the kinetics.