posted on 2012-08-30, 00:00authored byAnup Pramanik, Sunandan Sarkar, Pranab Sarkar
On the basis of density functional theory and nonequilibrium
Green’s
function technique, we have presented theoretical results on transport
properties of B- and N-doped aGNR p–n junction. The current–voltage
characteristic of this system indicates robust negative differential
resistance (NDR) behavior of it. Meanwhile, that p–n junction
diode can be utilized as a highly efficient voltage rectifier. The
calculations also reveal that the voltage rectifying efficiency can
be highly enhanced by forming a tandem diode by connecting two single
diodes in series. The variation of transport properties on the width
of aGNR is also investigated. The NDR phenomena as well as the rectifying
property can be well explained on the basis of relative shifting of
discrete energy states of the conjugate system with applied bias,
which in turn explains very strong coupling between the p and n regions
of the diode.