• Title/Summary/Keyword: Wacker process

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Fabrication and Characterization of Solar Cells Using Cast Polycrystalline Silicon (Cast Poly-Si을 이용한 태양전지 제작 및 특성)

  • 구경완;소원욱;문상진;김희영;홍봉식
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.2
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    • pp.55-62
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    • 1992
  • Polycrystalline silicon ingots were manufactured using the casting method for polycrystalline silicon solar cells. These ingots were cut into wafers and ten n$^{+}$p type solar cells were made through the following simple process` surface etching, n$^{+}$p junction formation, metalization and annealing. For the grain boundary passivation, the samples were oxidized in O$_2$ for 5 min. at 80$0^{\circ}C$ prior to diffusion in Ar for 100 min. at 95$0^{\circ}C$. The conversion efficiency of polycrystalline silicon solar cells made from these wafers showed about 70-80% of those of the single crystalline silicon solar cell and superior conversion efficiency, compared to those of commercial polycrystalline wafers of Wacker Chemie. The maximum conversion efficiency of our wafers was indicated about 8%(without AR coating) in spite of such a simple fabrication method.

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Study on the Graft Effect in Emulsion Polymerization of Poly(vinyl acetate-co-ethylene) Using Poly(vinyl alcohol) as Emulsifier (Poly(vinyl alcohol)를 이용한 Poly(vinyl acetate-co-ethylene) 에멀젼 중합에서 그라프트 연구)

  • Choi, Yong-Hae
    • Journal of Adhesion and Interface
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    • v.12 no.1
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    • pp.1-10
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    • 2011
  • An automated reaction calorimeter was used to directly monitor the rate of emulsion polymerization of vinyl acetate using poly(vinyl alcohol) (PVAs) having different degrees of blockiness. By using this technique in conjunction with other off-line measurements of the evolution of particle size distributions, important details of the process were observed. No constant graft rate period was observed for both low and high initial monomer-water ratios. The gel effect was observed for the low monomer-water ratio recipe. The particle size distributions were broad (particle diameter 40~100 nm) and bimodal. Continuous nucleation was observed to be accompanied by 'limited aggregation' and flocculation during the particle growth stages. It was speculated to be due to the occurrence of the extensive 'limited aggregation' and chain transfer to PVA leading to grafting.