Transient Behaviour of Space‐Charge‐Limited Currents in p‐Type Silicon

Calculation of the leading transients of space‐charge‐limited currents, neglecting diffusion, predict a “cusp”‐type behaviour which until now has only been confirmed on low mobility materials under optical excitation. On Si samples with p+‐contacts and on Pt‐contacted uncompensated (trap‐free) 60 kωcm crystals it is possible to obtain quantitative agreement at least after the first few ns. This provides a good method for measuring majority carrier mobilities. The origin of an order of magnitude deviation for times small compared with the transit time seems uncertain.