▎ 摘　　要

We have investigated the electron tunneling through a trapezoidal barrier in graphene The dependence of the transmission on the applied bias is obtained The trapezoidal barrier removes the negative differential resistance in the current voltage characteristics Furthermore the slope of the trapezoidal barrier can also be used as a parameter to control the angular distribution of the transmitted electrons The result can be used to design graphene-based tunneling devices such as an energy filter (C) 2010 The Japan Society of Applied Physics