Proceedings of nanoGe Fall Meeting19 (NFM19)
Publication date: 18th July 2019
Since their discovery in the beginning of the 90s, colloidal quantum dots (QDs) have moved from purely academic interests to an implementation into consumer products such as high-end displays. This jump into industrial applications has led to an increased focus on heavy metal free materials such as indium phosphide. InP QDs can be produced via different type of syntheses, the most well-known ones involving the use of tris(trimethyl)phosphine or aminophosphine as the phosphorus precursors [1]. Both methods require a shelling of the InP core by a wider band gap material, such as ZnS or ZnSe, in order to obtain efficient luminescence properties. Zn carboxylates are mostly used as the Zn source, possibly leading to high photoluminescence quantum yield but also to an uncontrolled oxidation of the InP core [2]. Here, we developed and study a novel and efficient method to growth ZnSe using the oxygen-free ZnCl2 as the zinc source. We hypothesized that the mechanism of this new reaction involves a nucleophile attack on a complex formed by the ZnCl2 and selenium precursor by amine function of the solvent. This reaction leads to a phosphorus-containing by-product that has been detected using mass-spectrometry and NMR spectroscopy techniques such as HMBC.
This new shell growth chemistry suggests that the behavior of the reaction components could be extended to other II-VI materials, such as, for example, ZnS, ZnTe or CdSe.
Leila Mingabudinova thanks the SIM Flanders for the financial support and the Hercules foundation for funding the 500 MHz NMR equipmentused in this research.