Inhomogeneity in photoconductors

We undertook a study of resistivity inhomogeneity in semiconductors containing deep impurities to determine (i) its influence in techniques used to characterize such materials, and (ii) what sample preparation and operating conditions minimize inhomogeneity and/or its effect. Zinc-compensated silicon was used as a specific example in both the calculations and the measurements. Several important results are presented which not only demonstrate the pitfalls of neglecting inhomogeneity in materials research, but also propose methods of coping with it.