  We report the growth of high quality Bi$_{2-x}$Sb$_x$Te$_{3-y}$Se$_y$
ultrathin nanoplates (BSTS-NPs) on an electrically insulating fluorophlogopite
mica substrate using a catalyst-free vapor solid method. Under an optimized
pressure and suitable Ar gas flow rate, we control the thickness, the size and
the composition of BSTS-NPs. Raman spectra showing systematic change indicate
that the thicknesses and compositions of BSTS-NPs are indeed accurately
controlled. Electrical transport demonstrates that a robust Dirac cone carrier
transport in BSTS-NPs. Since BSTS-NPs provide superior dominant surface
transport of the tunable Dirac cone surface states with negligible contribution
of the conduction of the bulk states, BSTS-NPs provide an ideal platform to
explore intrinsic physical phenomena as well as technological applications of
3-dimensional topological insulators in the future.
