Impact of temperature difference on the features of spray deposited yttrium doped cobalt selenide (YCoSe) thin films for photovoltaic application

In this investigation, spray deposited yttrium doped cobalt selenide (YCoSe) thin materials were synthesized in soda lime glass and the impact of substrate temperature (140 oC, 160 oC, 180 oC and 200 oC) on their elemental composition, surface morphology, structural, electrical and optical properties were investigated using scanning electron microscopy-SEM X-ray diffraction –XRD, four-point probe and UV-VIS spectrophotometer respectively. The EDX plots of the deposited undoped and Y-doped cobalt selenide revealed the major elements: cobalt, selenium and yttrium. This confirms the deposition of CoSe and Y-doped CoSe thin materials. The morphology of undoped CoSe thin materials was very rough containing randomly oriented non-uniform thin particles while addition of Y dopant (0.1 mol%) at substrate temperature of 140 oC gave a homogenous distribution of compact rectangular-like nanograins. The XRD result shows that the films are cubic polycrystalline in nature and the film grown at substrate temperature of 180 oC was seen to give the most excellent crystalline quality and a preferential orientation along (111) direction. From electrical results it was observed that increase in substrate temperature increased the film thickness with decreased resistivity and increased conductivity. The optical properties were found to vary with substrate temperature despite the fact that the variation was not totally linear, as the film deposited at substrate temperature of 160 oC deviated from the linearity in all the optical properties. The energy band gap of the deposited samples ranges from 1.25 eV–1.75 eV. The materials produced could be used in the production of photovoltaic devices

Dual Solution Synthesis and Characterization of Sns:Zns Alloyed Thin Films and Possible Applications in Solar Systems and Others

Communication in Physical Sciences, 2023, 9(2):172-198 Authors: Elizabeth C. Nwaokorongwu, Daniel A. Asiegbu, Lebe Nnanna, Ugochukwu Joseph, Akpu Nwamaka and K.U.P. Okpechi Received: 12 March 2023/Accepted 18 May 2023/ Energy is required for the creation of wealth and sustainability of development. The importance of energy in economic development has been recognized historically but the equitable distribution of energy amongst the masses has generated great concern in recent times.  This study was conducted to investigate the influence of varying annealing temperatures on the synthesis and characterization of SnS:ZnS alloyed thin films for solar applications. SnS:ZnS alloyed thin films were successfully deposited on glass substrates using two solutions-based methods: electroless and SILAR. The deposited alloyed sulphides were annealed between (373-423) K using a master chef annealing machine. The crystallographic studies were done using X-ray diffractometer and scanning electron microscope which indicates that the samples are polycrystalline and have cubic crystal systems. Rutherford Back Scattering analysis confirmed the percentage of the elements of tin, zinc and sulphur in the alloyed sulphide thin films. The results of the findings revealed that alloyed materials were deposited. The deposited materials were uniform and adherent to the substrates. The structural properties show that SnS:ZnS are polycrystalline. The microstructure shows the optical micrograph of the deposited samples. The properties exhibited make the films good material for protective coating, window coating, galvanization of metal and non-metal surfaces to prevent corrosion, etc. These properties also enhanced the material suitability for photovoltaic (PV) in solar energy conversion, sensors for the detection of poisonous substances most especially in the Oil-producing areas, light emitting diode (LED) and flat panel displays for optoelectronic applications