  Strong disorder has a crucial effect on the electronic structure in quantum
materials by increasing localization, interactions, and modifying the density
of states. Bi$_x$TeI films grown at room temperature and \SI{230}{K} exhibit
dramatic magnetotransport effects due to disorder, localization and electron
correlation effects, including a MIT at a composition that depends on growth
temperature. The increased disorder caused by growth at 230K causes the
conductivity to decrease by several orders of magnitude, for several
compositions of Bi$_x$TeI. The transition from metal to insulator with
decreasing composition $x$ is accompanied by a decrease in the dephasing length
which leads to the disappearance of the weak-antilocalization effect.
Electron-electron interactions cause low temperature conductivity corrections
on the metallic side and Efros-Shklovskii (ES) variable range hopping on the
insulating side, effects which are absent in single crystalline Bi$_x$TeI. The
observation of a tunable metal-insulator transition and the associated strong
localization and quantum effects in Bi$_x$TeI shows the possibility of tuning
spin transport in quantum materials via disorder.
