Growth and characterization of α-Sn thin films on In- and Sb-rich reconstructions of InSb(001)

alpha -Sn thin films can exhibit a variety of topologically nontrivial phases. Both studying the transitions between these phases and making use of these phases in eventual applications requires good control over the electronic and structural quality of alpha -Sn thin films. alpha -Sn growth on InSb often results in out -diffusion of indium, a ptype dopant. By growing alpha - Sn via molecular beam epitaxy on the Sb-rich c(4 x 4) surface reconstruction of InSb(001) rather than the In -rich c(8 x 2), we demonstrate a route to substantially decrease and minimize this indium incorporation. The reduction in indium concentration allows for the study of the surface and bulk Dirac nodes in alpha -Sn via angle -resolved photoelectron spectroscopy without the common approaches of bulk doping or surface dosing, simplifying topological phase identification. The lack of indium incorporation is verified in angle -resolved and angle -integrated ultraviolet photoelectron spectroscopy as well as in clear changes in the Hall response.