  Using angle-resolved photoemission spectroscopy (ARPES), we studied bulk and
surface electronic band structures of narrow-gap semiconductor lead telluride
(PbTe) thin films grown by molecular beam epitaxy both perpendicular and
parallel to the {\Gamma}-L direction. The comparison of ARPES data with the
first-principles calculation reveals the details of band structures, orbital
characters, spin-orbit splitting energies, and surface states. The
photon-energy-dependent spectra show the bulk character. Both the L and
{\Sigma} valence bands are observed and their energy difference is determined.
The spin-orbit splitting energies at L and {\Gamma} points are 0.62 eV and 0.88
eV, respectively. The surface states below and close to the valence band
maximum are identified. The valence bands are composed of a mixture of Pb 6s
and Te $5p_z$ orbitals with dominant in-plane even parity, which is attributed
to the layered distortion in the vicinity of PbTe (111) surface. These findings
provide insights into PbTe fundamental properties and shall benefit relevant
thermoelectric and optoelectronic applications.
