(Invited) Synthesis and Surface Engineering of III-V Semiconductor Quantum Dots for Infrared Optoelectronic Applications

Colloidal quantum dots (QDs) have widely been considered as emerging candidates for solution-processable optoelectronic devices. Especially, QDs that are optically active in NIR and SWIR spectral windows, offer a great promise for infrared emitters, infrared photodetectors, photovoltaics, and biological imaging applications. It is thus essential to develop high-quality infrared QDs without the use of heavy metals such as cadmium, lead, or mercury. Among various semiconducting materials, III-V compound semiconductors show great potential in practical optoelectronic applications not only due to their wide tunability in the infrared region, but also due to their excellent optical and electronic properties. However, the synthesis of III-V semiconductor-based QDs has been limited by the lack of understanding about the precursors of group V elements such as P, As and Sb. In this presentation, we would like to discuss about the pnictogen precursors to synthesize various III-V QDs and also the surface properties of the resultant QDs. By controlling the reaction process with the pnictogen precursors, we achieve size and stoichiometry-tunable III-V QDs including InP, InAs, InSb and alloy QDs. Based on structural, analytical, optical, and electrical characterization of the QDs, we study the effects of surface treatments on their optoelectronic properties. We demonstrate that III-V QD thin films are promising candidate materials for infrared optoelectronic devices. Figure 1