Minority-carrier extraction and accumulation near metal-semiconductor interfaces

Abstract

Solution to the transport equations in the realm of ’’small signal theory’’ results in expressions for the electric field, and the excess minority-and majority-carrier densities as functions of distance from an injecting boundary. Two situations are examined for ’’lifetime’’ semiconductors, the ’’trap-free’’ case and the case with monoenergetic traps. With different boundary conditions, the new expressions apply equally to all four nonequilibrium processes: injection, exclusion, accumulation, and extraction. Results on extraction are supported by measurements on single-crystal Ge, before and after neutron bombardment (to introduce traps).