Informatics Publishing Limited

A. Bag ¹, S. Mallik ¹, C. K. Maiti ¹

Affiliations
1 VLSI Engineering Laboratory, Dept. of Electronics and ECE, Indian Institute of Technology, Kharagpur, IN

Abstract

Active layer thickness dependence of photovoltaic (PV) properties of heterojunction solar cells fabricated using Al-alloyed polycrystalline p-type β-iron disilicide [p-β-FeSi₂(Al)]/n-Si(100) is reported. Rapid thermal annealing (RTA) at 650°C was used for the formation of polycrystalline β phase of FeSi₂ which was confirmed by x-ray diffraction (XRD). Prior to deposition of active β-FeSi₂(Al) layer, a thin Al interlayer (~8 nm) was deposited, which got dissolved in underlying Si layer during RTA and formed a heavy Al-doped epitaxial-Si (p+-Si) interfacial layer. Indium-tin-oxide (ITO) was used as top electrode. The current density-voltage and photo response characteristics of the solar cells with different active layer thicknesses (~ 50 to 135 nm) measured at room temperature are reported. Under air mass (AM) 1.5 illumination, the maximum conversion efficiency was found to be 2.18% with a short circuit current density of ~18.28 mA/cm² and open-circuit voltage of ~425 mV. The solar cells showed a series resistance of 213.6 Ω and a shunt resistance of 481.5 Ω which resulted in a fill factor of 28.05%.

Keywords

β-FeSi₂, Solar Cell, Efficiency, Open-Circuit Voltage, Short Circuit Current.

Full Text

     

S. Mallik ¹, D. K. Roy ¹

Affiliations
1 Indian Oxygen Ltd., Calcutta, IN

Abstract

The techno-economic possibility of rebuilding Steel Mill Rolls by submerged arc welding process is well-known. It has been adopted as a regular practice in U.K., U.S.A., U.S.S.R. and continental countries. Initiative has also been taken by some Steel Plants in India in this respect and welding procedures have been successfully established for a few types of rolls. It is felt, however, that there is considerable scope to enlarge the reclamation activities to cover a wider range of rolls and also in developing the technique for manufacture of "Weld Surfaced" duplex rolls, a relatively new concept in the manufacture of rolls.

Full Text