Solar cells and global warming reduction.

Research article.This study proposes one way of addressing the issue of climate change and pollution using solar cells. The quality of life in developing and low-income countries is on the decline because of air pollution. Energy has a role to play in the quality of life and reduction of air pollution especially in those countries. A reduction in the usage of fossil fuels and biomass in these countries will help decrease the air pollution and emissions generated by such energy sources. About 1 million solar lanterns are capable of reducing greenhouse gas emissions by over 30 000 tons. The role of eco-friendly solar cells in elimination of air pollution cannot be overstated

Modeling of fabricated NiO/TiO2 P-N heterojunction solar cells.

Research articles.This paper reports modelling and theoretical validation of a fabricated NiO/TiO2 P-N heterojunction solar cell. The solar cell equations were modelled and thereafter theoretical validation of the fabricated solar cells was performed. Modelling tools were used to validate the influence of NiO material features such as deposition temperature, voltage and defect densities on the performances of an ITO/TiO2/NiO heterojunction solar cell structure. The working points used included a temperature of 350 oC, illumination of 1000 W/m2 using an AM1.5 lamp, with voltage range of 0 to 1.5 volts. The output gave Voc of 0.1445 V, Jsc of 247.959195E-6 mA/cm2 and FF of 37.87 % and Voc 0.7056 and Jsc 28.366911 mA/cm2 when both contacts were added. This opens a new frontier for modelling of metal oxide based thin film solar cells especially NiO thin film solar cells. These findings enhance the quest to develop affordable and sustainable energy and encourage further research in solar cell technologies in low-income countries

Design of a prototype generator based on piezoelectric power generation for vibration energy harvesting

The concept of harvesting energy in the ambient environment arouses great interest because of the demand for wireless sensing devices and low-power electronics without external power supply. Harvesting energy by vibration with piezoelectric materials can be used to convert mechanical energy into electrical energy that can be stored and used to power other devices. This conversion of vibrations (mechanical energy) to electrical energy using piezoelectric materials is an exciting and rapidly developing area of research with a widening range of applications constantly materialising. In this context, the goal of this paper is to develop a comprehensive prototype generator that can harvest vibration energy and convert it to electrical energy by providing the output power for optimisation and its performance. Two setups of prototype are used: a cantilever beam with tip mass at the end, and a cantilever beam without tip mass at the end. Data from the experiment is compared and analysed using MatLab. The results show that the power output of the prototype with the tip mass is greater than the power output without the tip mass. The experimental results led to a power optimisation from that prototype by different characteristic of piezoelectric ceramic plate.Department of Science and Technologyhttp://www.erc.uct.ac.za/jesa/jesa-contents.htm2018-11-30am2018Electrical, Electronic and Computer Engineerin

Experimental optimization of nanostructured nickel oxide deposited by spray pyrolysis for solar cells application.

Abstract available in PDF file

Fabrication of affordable and sustainable solar cells using NiO/TiO2 P-N heterojunction.

Research article.The need for affordable, clean, efficient, and sustainable solar cells informed this study. Metal oxide TiO²/NiO heterojunction solar cells were fabricated using the spray pyrolysis technique. The optoelectronic properties of the heterojunction were determined. The fabricated solar cells exhibit a short-circuit current of 16.8 mA, open-circuit voltage of 350 mV, fill factor of 0.39, and conversion efficiency of 2.30% under 100mW/cm² illumination. This study will help advance the course for the development of low-cost, environmentally friendly, and sustainable solar cell materials from metal oxides

Review of solar energy inclusion in Africa : a case study of Nigeria.

Conference Proceeding.This work reviews solar energy inclusion in Africa using Nigeria as a case study. It reviewed studies made on viability, challenges and solutions associated with making solar energy a viable energy option in Nigeria. The study highlighted data on current industry capacity of solar energy, installed PV capacity, and solar energy application distribution. It sheds light on solar energy initiatives and projects in Nigeria and solar energy capacity development in Nigeria. Success stories of solar energy and solar cell fabrication in Nigeria are presented. Existing government policies and legislation are discussed. The authors consider the challenges faced and the current and future prospects of solar power in Nigeria, and make recommendations regarding the speedy and seamless inclusion of solar energy in Nigeria and Africa as a whole

Influence of concentration on properties of spray deposited nickel oxide films for solar cells.

Research article.Spray pyrolysis technique was used to deposit various concentration of nickel oxide films on glass substrate. The Effect of varying precursor concentration on elemental, morphological and structural properties was investigated on the deposited NiO films. Nickel (II) acetate tetrahydrate precursor was used at substrate temperature of 350 oC. Precursor concentrations were 0.025, 0.05, 0.075 and 0.1 M. Scanning Electron Microscope (SEM) surface morphology revealed nanostructured films with particles densely distributed across substrates surface. Increased in surface grains was observed as the precursor solution increased. Elemental composition of NiO films revealed presence of Ni and O element. There was reduction in oxygen concentration as precursor solution increases. Amorphous structure was observed at concentration of 0.025 M while polycrystalline with cubic structure was observed at higher concentrations. Preferred orientation was along (1 1 1) peak with small intensity along (2 0 0) peak. XRD patterns have peak diffraction at (2θ = 37 o and 43 o) for (1 1 1) and (2 0 0) planes respectively and 64 o for (2 2 0) plane for 0.1 M. Film thickness grew with increase in precursor concentration. Film micro strain was observed to have compression for all precursor solution conspicuously revealing the effect of varied concentration on NiO films propertie

Influence of annealing on properties of spray deposited nickel oxide films for solar cells.

Research article.Nickel oxide thin films were deposited on soda lime glass substrates by spray pyrolysis technique (SPT). Post-deposition annealing was carried out at 450 oC. Effects of annealing on the structural, elemental and surface morphological properties of the thin NiO films were investigated. XRD confirms polycrystalline with cubic crystalline structures of deposited and annealed NiO films. Preferred orientation was along (1 1 1) peak with intensity along (2 0 0) peak improved by annealing. The annealing process improved on formation of crystalline phases. XRD patterns have peak diffraction at (2θ = 37 o, and 43 o) for (1 1 1) for deposited and annealed. Peak diffraction at (2θ = 64 o, and 79 o) for (2 0 0) planes for 0.1 M and annealed respectively. Annealing improved on the film thickness by over 10 %. Surface morphology of deposited and annealed NiO films reveals nanocrystalline grains with uniform coverage of the substrate surface with randomly oriented morphology. Larger flakes are formed as a result of the annealing process. EDX elemental NiO films composition revealed presence of Ni and O elements in NiO films. A decrease in oxygen concentration was also observed confirming positive effect of annealing as an optimization process. Optimization of nickel oxide deposition process parameters offers opportunities for efficient and affordable solar cells