  We demonstrate electron cooling in silicon using platinum silicide as a
superconductor contact to selectively remove the highest energy electrons. The
superconducting critical temperature of bulk PtSi is reduced from around 1 K to
0.79 K using a thin film (10 nm) of PtSi, which enhances cooling performance at
lower temperatures and enables electron cooling to be demonstrated from 100 mK
to 50 mK.
