Electrical properties of multicrystalline silicon produced by electromagnetic casting process: Degradation and improvement

The electrical properties of boron-doped multicrystalline silicon for photo voltaic applications, elaborated by the cold crucible pulling process, are studied by the photoconductivity decay method and the electron beam-induced current measurement technique. The bulk lifetime mapping of the minority c arriers in the as-grown silicon wafers is drawn up using both the technique s. Moreover, the consequence of phosphorus doping on the recombination prop erties of extended defects are studied using the EBIC measurements. Two dif ferent treatments are investigated in order to improve the electrical prope rties of the as-grown silicon wafers: (a) thermal phosphorus diffusion, for which the gettering efficiency is determined by the different treatment pa rameters; (b) remote plasma hydrogen passivation which leads to increase of the minority carrier lifetime. (C) 2001 Published by Elsevier Science B.V. All rights reserved.