Reply to the previous comments by Shibamuraetal.

摘要

It is pointed out that in the case of high fields the Townsend method discussed in the previous letter does not give a direct measure of the averege carrier because the electron distribution is anisotropic. An estimate of the rms depth of traps originating from density fluctuations is given based on the recent calculation of the electron mobility by Basak and Cohen. This value is in excellent agreement with those of the present author based on a completely different type of reasoning.