Nonlinear behavior of InP:Fe under high electric field

The I-V characteristics were investigated on both long liquid encapsulated Czochralski (LEC) and short epitaxial semi-insulating (SI) InP:Fe samples. These characteristics show a linear regime at low voltages followed for higher voltages by a nonlinear one and a current breakdown. This has been widely explained by the single injection theory of Lampert and Mark (1970). The authors show that these characteristics are more complicated than previously recognized and exhibit three further features: (1) The nonlinear behavior occurs at a field of 10 kV/cm independent of the temperature, the nature of the contacts, and the sample thickness. (2) A current transient occurs for LEC long samples from this critical field affecting the I-V characteristics. (3) A S-type negative differential conductivity takes place at a higher field. This behavior is explained by a field-enhancement of the deep-level capture cross section and impact-ionization of deep levels