Bose et al. [9] subjected powdered silicon obtained by magnesium reduction of rice husk ash at a temperature of 600-650 oC to melting and directional solidification and found that boron was the active impurity in the polycrystalline silicon ingot obtained. They determined the minority carrier life time of their polycrystalline silicon material to be of the order of 1-5μs and concluded that to be promising for photovoltaic applications. A minimum carrier lifetime requirement for efficient solar cells fabricated from multicrystalline silicon wafers is however estimated as 25 μs [11].