Solution-based synthesis of III–V quantum dots and their applications in gas sensing and bio-imaging

Abstract

• Solution-based development of III–V quantum dots. • Case study of In-based and Ga-based quantum dots. • A summary of solution-based synthetic approaches. • Detailed investigation of key factors for high-quality quantum dots. • Excellent performances of III–V quantum dots in several applications. In recent years, the syntheses of III–V quantum dots have attracted extensive interests because of their remarkable quantum-confinement-effects, other attractive properties such as large exciton radius and potential applications in a number of areas such as gas sensing and biological probing. Some III–V members are low toxic and suitable to be used in bio-system with their excellent fluorescent characteristics. Although a solution-phase preparation of III–V quantum dots has become possible, the synthesis approach is still in its infancy and the quality of III–V products is inferior to those of II–VI and IV–VI quantum dots due to some difficulties such as lack of suitable precursors, high covalent characteristic, and difficult control of their nucleation and growth. The size, size distribution and crystallinity are strongly dependent on a specific reaction procedure and preparation technique. It is also believed that the selection of suitable precursors and designing corresponding key reactions should hold the keys for a successful production of the desired III–V quantum dots. This article focuses on the solution-phase synthesis of In- and Ga-based III–V quantum dots, and these developments are presented through a classification of their chemical routes including metathesis, thermolysis, dehalosilylation and transmetalation with a discussion on their preparation techniques such as one-pot heating-up and hot-injection. Furthermore, III–V quantum dots acted in gas sensing and bio-imaging applications are outlined as well. Eventually, an outlook of current challenges and promising direction for the development of III–V quantum dot synthesis is provided.