On Tassicker´s measurement formula in the boundary biased-probe method

When using the boundary biased-probe method, the nonlinear curve attained in experiments is contradictory to the linearity expected when Tassicker´s formula is applied to this method. In this paper, the authors analyze the probe model theoretically and obtain a nonlinear relation. Their analysis shows that the space charge near by the biased probe is the main cause of this nonlinearity. This space-charge effect was ignored in Tassicker´s formula. Their theoretical analysis and experimental results show that Tassicker´s formula can be improved, in particular, when the electric field region is rich in space charge. In this paper, the authors propose a way to improve Tassicker´s formula