Quantum dots (QDs) are of considerable interest owing to their unique properties and their promising applications in high-performance optoelectronic devices such as single electron transistors, lasers, light emitting diodes, infrared photodetectors, and solar cells. For these applications, the control of the QDs size, shape, and size distribution is expected to play an important role in optoelectronic devices. In addition, carrier dynamics of QDs are very important, not only for the understanding of the fundamental physics of zero-dimensional structures, but also for improving the performance of optoelectronic devices. Furthermore, selective wavelength tuning of QDs is useful for the fabrication of monolithically integrated QD-based optoelectronic devices. In this talk, we present the various techniques to control and tune the structural and optical properties of QDs.