Novel synthetic routes towards zinc nitride quantum dots and half-heusler compounds such as LiZnN

The aim of the project is to develop new chemical routes for a range of luminescent nitride-based quantum dot materials, using air-sensitive inorganic and organometallic chemistry. Quantum dots have emerged as a key material in numerous applications, from biological imaging, to solar energy and displays. For such applications, heavy metal free, stable and brightly emitting materials are necessary for the next generation of devices.

Currently this project focuses on zinc nitride (Zn3N2) quantum dots (QDs). These are of great scientific interest due to their tune-able emission, from near infra-red (780 nm - 2500 nm) into the visible of the spectrum part (400 nm - 750 nm). Zinc nitride QDs have potential to be useful in the development of solar cells, electronics and in biomedical applications. Zinc nitride has the added advantage that, unlike current colloidal, well-developed nanocrystals (i.e. CdSe, PbS or InP), it consists of non-toxic and earth abundant materials. The current methods to synthesise zinc nitride are severely limited and have been reported to have been synthesised using highly pyrophoric diethyl zinc and explosive ammonia gas at high temperatures (225oC) from a research group in Oxford. We aim to produce bright red emitting materials using a more convenient and safer organometallic method, using zinc iodide and lithium amide precursors. Temperatures, ligand screening tests and change in reaction vessel conditions will be modified. Using emission spectra, absorption spectra, X-ray diffraction, XPS, TEM, SAED, EDX and QY measurements to determine the identity of the sample and its elemental constituents. An attempt will be made to shell these materials will be made using ZnS shells and/or InN graded alloy materials.