Abstract: The quantum mechanical method for the asymmetric double-barrier problem is too complicated to calculate,we study quantum tunneling characteristics of electron in both asymmetric single-potential barrier and double-barrier structures by using the transfer matrix method.The simple formula of transmission rate are obtained for two cases.The numerical results show that good conductivity switching effect appears in both single-barrier and double-barrier structures under the appropriate parameters.It is also shown that the transmission coefficient appears quantum oscillation if the incident electron energy is greater than the barrier height.We hope that the present results can provide reference value for R D in electronic devices.

Key words: asymmetric barrier, quantum tunnelig, transfer matrix, coherent transport