Relationship between net doping density and resistivity of compensated mc-Si ingots

The total concentration of doping species in both p- and n-type crystalline Si materials can be easily estimated by resistivity measurements. However, to use this relation for estimating the net doping density for compensated materials can be questioned due to the interaction between doping species. This study was undertaken in order to elucidate if resistivity measurements can be used to estimate the net doping density in materials with dopant densities characteristic for compensated solar cell silicon. The net doping density, N-A-N-D, of several p-type compensated mc-Si ingots with different contents of B and P has been independently measured by chemical analyses (GDMS) and resistivity measurements (FPP). N-A is assumed to be equal to the sum of B and Al atomic concentrations, whereas N-D is assumed to be equal to the P concentration. The net doping densities obtained by the two methods are in agreement within the uncertainty limits for the GDMS measurements, indicating that resistivity measurements give a good estimate of the net doping densities investigated here. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim