Halo old friend - improving InP with halogens Theo A. Gazis, Ashleigh J. Cartlidge, P. D. Matthews School of Chemical & Physical Sciences, Keele University, Staffs, ST5 5BG, UK
III-V QDs (e.g. InP) are environmentally benign and contain components that are relatively cheap, sustainable and earth abundant, so offer great promise, but unlike II-VI QDs are considerably harder to synthesise. One of the highest risk areas to the large scale uptake of InP QDs is the challenging to control surface chemistry, with both In and P being notoriously oxophilic. To overcome surface traps/defects, add air stability and improve optical properties, it has become standard practice to "shell" or encapsulate the QD in ZnS/S. This adds an additional layer of complexity to the system, and so we have been searching for an easier, lower cost method. 1 Here we report a two-fold approach to improvingoptical properties and conferring air stability to InP QDs. Firstly, post-synthetic treatment with an appropriate halide source results in a dramatic blue-shift in the UV-vis spectra, accompanied by a significant reduction in full-width half maximum of the lowest energy excited transition. This effect is caused by stripping back the oxidised surface of the InP QD, to reveal a core of pure InP. Secondly, we have replaced the standard long-chain carboxylates used to confer colloidal stability with silylated phosphines (R 2 PSiMe 3 ), thus removing all sources of oxygen from the reaction mixture. These species act as capping agents, replacing unstable surface P-SiMe 3 groups with saturated PR 2 moieties. 2 References 1. Nano Research , 022, 15, 4468 2. Chem. Commun. , 2022, 58, 13799
P194E
Made with FlippingBook Learn more on our blog