  In this article, we review recent progress in angle-resolved photoemission
(ARPES) studies of the Mott-Hubbard-type correlated electron systems SrVO3. It
has the d1 electron configuration and is an ideal model compound to study
electron correlation effects in normal metal. ARPES studies of bulk
single-crystal SrVO3 and CaVO3 have revealed the difference in the mass
renormalization of electrons between them. In-situ ARPES studies of thin films
fabricated by the pulsed laser deposition method have clarified not only
quasi-particle dispersions, which show a kink like high-Tc cuprates, but also
finite dispersions in the incoherent part. Self-energy in a wide energy range
has been deduced from the ARPES spectral weight using Kramers-Kronig
transformation. The obtained self-energy has several structures which yield the
incoherent feature and a pseudogap-like dip similar to the high-Tc cuprates.
Quantum-well states in ultrathin films of SrVO3 have revealed sub-bands with
correlated electrons. These findings of electron correlation effects outlined
in the present article would provide a starting point not only for fundamental
condensed-matter physics but also for the development of new devices with
correlated electrons.
