  In this article, we present our results on bilayers assembled upon strategic
placement of Cd$_6$Se$_6$ clusters. These bilayers are studied for their
stability and electronic structure with the help of density functional theory
and are further analyzed using Bardeen, Tersoff and Hamann formalism for their
tunneling properties. Our calculations show that the hexagonal arrangement of
these clusters prevails as the most stable geometry showing all real phonon
modes. First-principles molecular dynamics studies on this 2D structure show
that it remains intact even at room temperature. This bilayer shows an indirect
semiconducting band gap of 1.28~eV with the current-voltage (I-V)
characteristics similar to a tunnel diode. Further, we functionalized this
bilayer using transition metal atoms, Co and Cr. The aim was to seek whether
the bilayer sustains magnetism and how the concentration affects its electronic
and magnetic properties. Co functionalization brings ferromagnetic ordering in
the bilayer which turns near half-metallic upon increasing the concentration.
On the other hand, Cr functionalization shows a transition from antiferro- to
ferromagnetic ordering upon increasing the concentration. The I-V
characteristics of all these functionalized bilayers show negative differential
conductance similar to a tunnel diode.
