  1T-TaS$_2$ exhibits several resistivity phases due to the modulation of
charge density wave (CDW). The fact that such phase transition can be driven
electrically has attracted a lot of attention in the recent past towards
\emph{active-metal} based electronics. However, the bias-driven resistivity
switching is not very large ($<$ 5 fold), and an enhancement in the same will
highly impact such phase transition devices. One aspect that is often
overlooked is that such phase transition is also accompanied by a significant
change in the local temperature due to the low thermal conductivity of
1T-TaS$_2$. In this work, we exploit such electrically driven phase transition
induced temperature change to promote carriers over a thermionic barrier in a
1T-TaS$_{2}$/2H-TaSe$_{2}$/2H-MoS$_{2}$ T-Junction, achieving a $964$-fold
abrupt switching in the current through the MoS$_2$ channel. The device is
highly reconfigurable and exhibits an abrupt reduction in current as well when
the biasing configuration changes. The results are promising for several
electronic applications, including neuromorphic chips, switching, nonlinear
devices, and industrial electronics such as current and temperature sensing.
