Portrait of a UK-Africa Capacity Building Initiative Consortium 2015-2022: the Cameroon, Ghana, South Africa and United Kingdom Materials Initiative (CaGSUMI) for developing materials for solar cells

The CaGSUMI consortium was funded by the Royal Society-Department for International Development (later the Foreign, Commonwealth & Development Office) on the Africa Capacity Building Initiative programme between the years 2015 and 2022 and involved three Sub-Saharan African universities: Kwame Nkrumah University of Science and Technology, Kumasi, Ghana, University of Yaoundé I, Cameroon, and the University of Zululand, South Africa; and the University of Manchester in the United Kingdom. The project was used to cement an emergent UK-Africa network in the areas of materials chemistry related to renewable energy generation with both thin films and nanomaterials. The consortium's outputs led to numerous publications of African science in international journals, a number of graduated PhDs who went on to permanent academic positions and prestigious fellowships, the establishment of a capacity-building plan relevant to the chemistry departments in each of the African countries, and the installation of a number of first-in-kind pieces of kit for African laboratories that will keep them on a competitive footing at an international level for the next decade and more.

Zinc and cadmium thioamidate complexes: rational design of single-source precursors for the AACVD of ZnS

A series of zinc(II) thioamidate complexes [Zn{SC(iPr)NR}2]n for R = iPr (n = 2) (2), tBu (3) (n = 1), Ph (4) (n = 2) and Cy (5) (n = 2) and one cadmium(II) thioamidate complex [Cd{SC(iPr)NtBu}2]3, (6), were designed and synthesised as single-source precursors for AACVD ZnS and CdS. Solid-state structures of all four zinc(II) compounds revealed distorted tetrahedral or trigonal bipyramidal geometries, with varying tendencies for dimeric association, mediated by {Zn-S} bridging bonds. The thermogravimetric analysis identified the {tBu} derivertive, 3, as the most promising precursor based on its low decomposition onset (118 °C) and clean conversion to ZnS. This was attributed to the greater availability of β-hydrogen atoms promoting the pyrolysis mechanism. The corresponding cadmium thioamide 6 was found to crystallise as a trimetallic molecule which lacked the thermal stability to be considered viable for AACVD. Hence, 3 was used to deposit ZnS thin films by AACVD at 200-300 °C. Powder X-ray diffraction confirmed phase-pure growth of hexagonal wurtzite ZnS, with approximate crystallite sizes of 15-20 nm. Scanning electron microscopy revealed densely packed spherical nanoclusters. The morphology and crystallinity were most consistent for depositions between 250-300 °C. Energy dispersive X-ray spectroscopy indicated slightly sulfur-deficient stoichiometries.