We present a model and results of self-consistent calculation of current–voltage (I–V) characteristics of the InAs/AlSb/InAs, InAs/AlSb/GaSb resonant tunneling structures with type II heterojunctions. The different current components, charge accumulation in the quantum well and quasi-Fermi level variation in contacts and spacers due to the drift-diffusion processes, are taken into account. The kp band model is used to describe the interband and intraband tunneling processes. The transfer Hamiltonian approach is employed to obtain the resonant tunneling current density and charge density in the quantum well. A good quantitative agreement with the experiment is obtained for both structures including the agreement for the values of peak-to-valley (P/V) current ratio. © 1997 American Institute of Physics.