Semiconductor quantum dots for future optical applications

Research and development of the semiconductor quantum dots (QDs) for optical applications are reviewed. The QDs are small crystals composed of ILL-V, II-VI, IV and IV-VI semiconductors, the size of which is about 10 nm. They are categorized into two groups. One is called the self-assembled QDs which are grown epitaxially on the semiconductor substrate, and the other is the colloidal QDs synthesized in the solvent using chemical technique. Since the emission wavelength of both QDs covers wide range, i.e., from visible to infrared, the QDs are attractive to various application fields. In this article, we focus on the progress in the three application fields, i.e., the replacement of existing products, the quantum information devices, and the solar cells.