  SrxBi2Se3 is a candidate topological superconductor but its superconductivity
requires the intercalation of Sr by into the van-der-Waals gaps of Bi2Se3. We
report the synthesis of SrxBi2Se3 thin films by molecular beam epitaxy, and we
characterize their structural, vibrational and electrical properties. X-ray
diffraction and Raman spectroscopy show evidence of substitutional Sr alloying
into the structure, while transport measurements allow us to correlate the
increasing Sr content with an increased n-type doping, but do not reveal
superconductivity down to 1.5K. Our results suggest that Sr predominantly
occupies sites within a quintuple layer, simultaneously substituting for Bi and
as an interstitial. Our results motivate future density functional studies to
further investigate the energetics of Sr substitution into Bi2Se3.
