Window Layer Thickness Effect on Amorphous Silicon Oxide Solar Cell Performances

The recent research and developments of a-Si:H based solar cells have greatly promoted its position as low cost solar cell. Unfortunately, a-Si:H solar cells suffer appreciable light induced degradation for thickness greater than 200nm. It has been reported that boron doped hydrogenated amorphous silicon oxide (p-a-SiOx:H) films have a low temperature coefficient compared to those based on hydrogenated amorphous silicon (p-a-Si:H) . Moreover, the solar cells with a p-a-SiOx: H generate more electricity than the solar cells with p-a-Si: H window layer due to the wider band gap (Eg) of these films. We present in this paper a computer simulation on the effects of window layer thickness on the performances of single junction amorphous silicon oxide solar cells. We varied the thickness of the window layer from 5 nm to 25 nm and our simulation results showed that cells parameters are significantly affected window layer thickness. However, the film thickness of the p-a-SiOx:H window layer increased from 5 nm to 25 nm, the power conversion efficiency (PCE) of the solar cells respectively decreased in the ranges of 5.733% to 5.271% .the simulation data are in good agreement with the literature

Recovery of Sulfur-Alkaline Waste by Processing into Cellular Silicate Material

The formation of cellular silicate glasses from sulfide-alkaline solutions and amorphous silicon oxide has been studied. The mechanism of formation of silicates from sodium hydroxide and amorphous silicon oxide and processes of gasification with the participation of the organic component of waste are considered. Technological solutions for recovery of sulfide-alkaline solutions are proposed. At the same time, the process of recovery consists in mixing sulfuralkaline waste with natural amorphous silicon oxide, tripoli, and further roasting the resulting composition at glass formation temperatures. As a result of heat treatment, sulfur from organosulfur compounds is oxidized to sulfur (IV), and sodium hydroxide, after dehydration, enters in composition of the resulting vitreous silicate cellular material.