  We show that a semiconductor thin film can acquire a non-trivial spin texture
due to the proximity effect induced by a topological insulator. The effect
stems from coupling to the topological surface states and is present even when
the insulator is doped. We propose a semiconductor/topological insulator
heterostructure as a device that allows measuring interface properties and
probing surface states in uncompensated samples. We also find that the
topological insulator surface modes can be significantly broadened and shifted
by the presence of metallic contacts.
