Browsing by Author "Masikini, M"

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    Electronics of anion hot injection-synthesized te-functionalized kesterite nanomaterial
    (MDPI, 2021) Nwambaekwe, K.C; Masikini, M; Mathumba, P
    Metal chalcogenides such as copper zinc tin sulfide (CZTS) have been intensively studied as potential photovoltaic cell materials, but their viability have been marred by crystal defects and low open circuit potential (Voc) deficit, which affected their energy conversion efficiency. Strategies to improve on the properties of this material such as alloying with other elements have been ex-plored and have yielded promising results. Here, we report the synthesis of CZTS and the partial substitution of S with Te via anion hot injection synthesis method to form a solid solution of a novel kesterite nanomaterial, namely, copper zinc tin sulfide telluride (CZTSTe). Particle-size analyzed via small angle X-ray scattering spectroscopy (SAXS) confirmed that CZTS and CZTSTe materials are nanostructured. Crystal planes values of 112, 200, 220 and 312 corresponding to the kesterite phase with tetragonal modification were revealed by the X-ray diffraction (XRD) spectroscopic analysis of CZTS and CZTSTe. The Raman spectroscopy confirmed the shifts at 281 cm−1 and 347 cm−1 for CZTS, and 124 cm−1, 149 cm−1 and 318 cm−1 for CZTSTe.
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    Enhanced electrochemical glucose sensing performance of CuO:NiO mixed oxides thin film by plasma assisted nitrogen doping
    (Elsevier, 2021) Cummings, F; Palmer, M; Masikini, M
    In this study plasma-assisted nitrogen doping of a CuO–NiO mixed oxide thin film was presented. The as prepared film was also applied as a glucose sensor. The nitrogen species generated during plasma ignition resulted in a beneficial phase transformation of CuO to Cu2O. Characterisation techniques such as XRD, SEM, EIS and Hall Effect etc. measurements were utilized to study the morphology, structural features, doping profile and electrical properties of the sensing material. Device performance electrochemical testing showed that the as-developed sensor (labelled as N–CuO/Cu2O:NiO) showed an ultra-fast response time of 2.5 s with high sensitivity (1131 μA/mM.cm2). The linear range of the sensor was calculated to be up to 2.74 mM of glucose and excellent selectivity towards glucose at an applied potential of +0.67 V vs Ag/AgCl in 0.1 M NaOH electrolyte solution.