Simulation analysis on impurity distribution in mc-Si grown by directional solidification for solar cell applications

Abstract

Abstract We carried out global transient simulation of impurity distribution in multi-crystalline silicon grown by directional solidification using appropriate software. Non-metallic impurities such as carbon, nitrogen and oxygen originate from the furnace parts and each impurity atom was segregated into the mc-Si ingot based on their solubility in the crystal. During the solidification process the temperature distribution causes melt fluctuation in the Si melt, which is controlled by applying an external body force that leads to a uniform distribution of impurity atoms. Here the uniform distribution of impurity atoms was obtained by rotating the crucible at 10 rpm and the investigations were also carried out without crucible rotation and with a crucible rotation rate of 3 rpm. In this paper we have analyzed the segregation of non-metallic impurity atoms and chemical reactions between the impurity atoms, wherein three types of simulations were carried out and their results analyzed.