Synthesis and characterization of molybdenum dichalcogenides nanoparticles via solution-processed technique for photovoltaic applications

Energy generated from non-renewable energy sources has a drawback of prompted outflow of ozone harming substances. These drawbacks of the non-renewable energy have quickened innovative work of renewable power sources, since they have an advantage of the provision of a better, preserved, decent environment that is free from natural contamination and commotion. Photovoltaic devices are prevalent in improving the green energy utilization and defeating the natural concerns yielded from the current most overwhelming energy sources. Herein, the synthesis, characterization, and application of Molybdenum chalcogenide nanoparticles (NP) as alternative sources in the absorber layer of quantum dot solar sensitized cells (QDSSCs) is discussed. The MoS2 NPs were synthesized from the aliphatic and aromatic dithiocarbamate (DTC) ligands and complexes as precursors. The successful synthesis of the DTC ligands and MoDTC complexes was confirmed through characterization with a variety of techniques including 1H and 13C-NMR, Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-VIS), Thermogravimetric analysis (TGA) and Derivative thermogravimetric (DTG) analysis. The synthesized MoDTC complexes (precursors) were further used in the synthesis of MoS2 nanoparticles. A bottom -up colloidal approach was employed for the synthesis of the MoX2 NPs. The successful synthesis of the NP was confirmed as the results from the diffractive peaks obtained from XRD which were positive and agreed in comparison with the standard. The diffractive peaks were shown in the planes (100), (002), (100) and (105) for MoS2 nanoparticles; (002), (100), (103) and (110) for MoSe2 and (0002), (0004), (103) as well as (0006) for the MoTe2 nanoparticles. The MoSe2 nanoparticles showed the least size of the nanoparticles followed by MoTe2 and lastly MoS2. These results agreed with the results obtained using SEM analysis. For the optical properties of the nanoparticles, UV-VIS and PL were used, the shift of the peaks from the red shift (600 nm) to the blue shift 270-5 nm and 287-9 nm (UV-VIS) confirmed that the nanoparticles were quantum confined. The application of the MoX2 NPs in QDSSCs was done with MoSe2 showing the greatest PCE of 7.86 percent followed by MoTe2 6.93 percent and lastly MoS2 with a PCE of 6.05 percent and 5.47 percent.Thesis (MSc) (Chemistry) -- University of Fort Hare, 202