  Reducing the contact resistance of field-effect transistors based on
two-dimensional materials is one of the key improvements required to to enable
the integration of such transistors in an industrially relevant process.
Suitably designed lateral heterojunctions provide an opportunity to
independently tailor the contact and channel properties and to mitigate the
problem of high contact resistance. Inspired by the recent experimental
demonstration of a two-dimensional $p$-type Schottky barrier, here we use
quantum transport simulations to estimate the performance of $p$-type
transistors in which the channel consists of a lateral heterostructure of
NbS$_2$/MoS$_2$/NbS$_2$ (semimetal-semiconductor-semimetal). We find that the
gate alignment with the channel is a critical design parameter, strongly
influencing the capability of the gate to modulate the Schottky barrier at the
MoS$_2$/NbS$_2$ interfaces. This effect is also found to significantly affect
the scaling behavior of the device.
