Spectral Selective Properties and Possible Applications of Iron Zinc Sulphide Ternary Thin Film

Iron zinc sulphide ternary thin film has been grown on glass substrate and characterized using a spectrophotometer. The optical properties considered revealed high absorbance and reflectance but low transmittance in the UV; low values of absorbance and reflectance accompanied by high transmittance in the VIS. The direct band gap and indirect band gap obtained are 2.3eV and 1.9eV. The possible applications were discussed

Solid State Properties of Copper- Silver- Sulphide Thin Film Deposited by Solution Growth Technique

Chemical bath deposited Copper Silver Sulphide (CuAgS) thin films on glass substrates were studied for its optical properties using spectrophotometer. Some of the optical properties studied include absorbance, transmittance, reflectance, refractive index, optical conductivity, absorption coefficient, dielectric constant and extinction coefficient. The direct band gap obtained is 2.3eV and the indirect band gap is 1.1eV. Some of the possible applications of the film were discusse

Design and Construction of a Wooden Solar Box Cooker with Performance and Efficiency Test

A wooden solar box cooker was successfully constructed with cheap and locally available material with efficiency of .From the various experiments that were carried out, the highest temperature gotten both on the ground floor and at the top of the roof was 720C both on the days with air temperature of 380C and 350C respectively. Efficiency was found to increase with decreasing temperature difference between collector temperature and ambient temperature. Increase in temperature does not necessarily lead to increase in efficiency. Efficiency decreased with decreasing solar radiation

Growth and Characterization of Lead Sulphide Thin Film for Solar Cell Fabrication

Lead Sulphide thin film was deposited on glass substrate prepared from lead acetate and thiourea solution using solut ion growth technique. XRD studies show that, films prepared are in nanocry s tal l ine range. Also the diffraction peaks are found to be in good agreement with standard ASTM data. Optical studies show that the band gap energy is in the range of 0.75eV – 1.98eV. SEM studies show that the film surface have uni form grains and the grain size obtained are of the order of 15-20 nm and this is in agreement with the calculated values from the XRD result . Electrical resistance is in the range of 150 Giga Ohms. Vicker’

Photo-Thermal Solar Energy Conversion Device

Photo-thermal solar energy device was constructed using local available materials for producing hot water for house hold uses. The motivation for this research is to find an alternative source of power for this purpose, since we have epileptic supply of conventional power in the country. It was observed that intensity of solar radiation varies with time and the temperature of water produced depended on the amount of solar radiation and the time of the day as observed from the graphs plotted. We obtained boiling water at 100 degrees Celsius with the device at Covenant University, Ota, Ogun State. Nigeria

The Interconnectivity of Weather System and Ozone Concentration Over West Africa

The relationship between some meteorological parameters and ozone distributions as revealed by satellite EPTOM over four West African stations namely, Lagos (Nigeria), Dakar (Senegal) Lamto (Ivory Coast) and Ekona (Cameroon) was studied for the period 1997 to 2002. The mean ozone concentration over these stations for the period were 270.8±0.3DU at Lagos, 264.9±0.3DU at Dakar, 269.8±0.3DU and 269.0±03DU at Lamto and Ekona respectively. The average monthly maximum ozone concentration of 288.6DU and 285.1DU respectively were observed for Lagos and Dakar, between July and August, which coincided with the period of tropical summer rain-fall over the West African region. This coincidence could be attributed to reduction in the effect of the extra-tropical suction pump (ETSP) action responsible for the transportation of ozone concentration from the tropical stratosphere into the mid and high latitudinal region. This re-duction may be due to decrease in the atmospheric heat engine expected to drive the ETSP, as the tropical surface temperature and evaporation are at their minimum during the raining sea-son. The surface temperature and evaporation at Lagos-Nigeria both had significant negative correlation values of -0.73 and -0.68 with the ozone concentration respectively

POWER TRANSISTOR AND PHOTODIODE AS A SOLAR CELL DEVICE

Novel solar panel using BPW41N Photodiode have been developed. The panel produced current of 714μA at 6.17V and 375μA at 8.60V using type A and B respectively. The combination of type A and B produced current of 395μA at 13.80V which is a 5.45mW solar panel

Effect of Processing Methods on Nutritive and Antinutritive Properties of Seeds of Brachystegia eurycoma and Detarium microcarpum from Nigeria

Proximate analysis of the seeds of Brachystegia eurycoma and Detrarium microcarpum were carried out on both the dehulled and undehulled samples of the flour. The protein content of the seeds are quite low 9.1;7.2 and 11.4;8.2 for undehulled and dehulled Brachystegia eurycoma and Detarium microcarpum, respectively. Crude fibre is less than 3% in each, while ash was less than 5% each per 100gm dry weight of sample. Detarium microcarpum has a higher crude fat composition 18.5±0.03, 15.5±0.02 while Brachystegia eurycoma 15.5±0.04, 14.0±0.01 for the undehulled and dehulled samples respectively. Moisture content is higher in dehulled samples 14.3±0.01 and 16.7±0.03 for both seed types. The available carbohydrate is equally higher in the dehulled samples 59.0±0.01 and 57.0±0.01, respectively for both seeds. The sodium, potassium, calcium and magnesium contents were less than 1% each, with calcium having the highest concentration, followed by phosphorous. The phytochemical analysis showed the presence of alkaloids, tannins, saponins and flavonoids. Brachystegia eurcoma showed no presence of tannin. The findings are of nutritional relevance since these seeds are used for soup thickening by many homes in the southeastern Nigeria

Phytochemical Analysis of Leaf-Extracts from Eight Tropical Trees: Prospects for Environmentally-Friendly Dye Compounds for Smart Windows

The crude extract of eight specimen leaf samples were studied by phytochemical analysis for investigating prospects of the extracts for environmentally-friendly dye compounds that could be useful for smart windows. The phytochemical analysis reveals the presence of phytoconstituents such as flavonoids, anthraquinones, tannins, saponins, thus suggesting presence of compounds that could be useful as dye for smart windows in the chromophore of the plant. As a preliminary test, dye pigment grown on glass from the extracts, using the Solution Growth Technique, exhibited low absorbance and high reflectance at transmittance set at 400 nm when studied using UV/VIS spectroscopy between 190 nm and 1100 nm wavelength i.e. within the visible range of light in the electromagnetic spectrum. These indicated suitability of the leaf-extracts from the studied plants for growing environmentally-friendly dye compounds that could be used for smart windows

GROWTH AND CHARACTERIZATION OF TERNARY CHALCOGENIDE THIN FILMS FOR EFFICIENT SOLAR CELLS AND POSSIBLE INDUSTRIAL APPLICATIONS

Ternary thin films of Iron Copper Sulphide (FeCuS), Iron Zinc Sulphide (FeZnS), Lead Silver Sulphide (PbAgS), Copper Silver Sulphide (CuAgS) and Copper Zinc Sulphide (CuZnS) were grown using cheap and simple solution growth technique with EDTA, TEA and NH3 as complexing agents. The deposited films were characterized using PYE-UNICO-UV-2102 PC spectrophotometer, and optical microscopy. The results suggest that some of the films have crystal structures. From the spectral analysis of absorbance/transmittance, the optical and solid state properties were deduced. The other optical properties so obtained include the reflectance, absorption coefficient, refractive index, extinction coefficient, optical conductivity and thickness, while the solid state properties are dielectric constant and band gap energy. For all the five categories of thin films grown (i.e. FeCuS, FeZnS, PbAgS, CuAgS and CuZnS), absorbance was high in UV and low in VIS-NIR-regions, while the transmittance were low in UV-region and high in VIS-NIR-regions. The reflectances were high in UV-region and low in the VIS-NIR-regions. For FeCuS, FeZnS, PbAgS, CuAgS and CuZnS, the absorption coefficient ranged from 0.1x106 m-1 to 1.65x106 m-1, 0.2x106 m-1 to 2.3x106 m-1, 0.5x106 m-1 to 0.9x106 m-1, 0.5x106 m-1 to 1.28x106 m-1 and 0.24x106 m-1 to 1.6x106 m-1, respectively. The real part of the refractive index ranged from 1.2 to 2.3, 0.72 to 2.3, 0.1 to 2.3, 1.94 to 2.28 and 1.6 to 2.3, respectively. The corresponding values of optical conductivity ranged from 0.03x1014 s-1 to 0.6x1014 s-1, 0.07x1014 s-1, 0.06x1014 s-1 to 0.6x1014 s-1, 0.24x1014 s-1 to 0.6x1014 s-1 and 0.12x1014 s-1 to 0.6x1014 s-1, respectively. The extinction coefficient, ranged from 0.005 to 0.038, 0.004 to 0.056, 0.010 to 0.140, 0.025 to 0.064 and 0.008 to 0.082, respectively. The direct band gap ranged from 2.4eV to2.8eV for FeCuS, 2.9eV for FeZnS, 1.5eV to 2.1eV for PbAgS, 2.3eV for CuAgS and 2.2eV to 2.4eV for CuZnS. The values of the indirect band gap were in the range 0.6eV to 1.0eV for FeCuS, 1.9eV for FeZnS, 0.3eV to 0.8eV for PbAgS, 1.1eV for CuAgS and 0.4eV to 0.9eV for CuZnS. The real part of the dielectric constant ranged from 1.4 to 5.2, 0.7 to 5.2, 0.4 to 5.2, 3.8 to 5.2 and 2.2 to 5.2, respectively, while the corresponding imaginary part of the dielectric constant ranged from 0.008 to 0.136, 0.008 to 0.164, 0.010 to 0.390, 0.100 to 0.290 and 0.030 to 0.360, respectively. The range of band gaps, 1.5eV to 2.9eV makes the films suitable for solar cells fabrication; this is in agreement with the finding for the film FeCdS