  We report on a systematic study of electronic transport in tetracene single
crystals by means of space charge limited current spectroscopy and time of
flight measurements. Both $I$-$V$ and time of flight measurements show that the
room-temperature effective hole-mobility reaches values close to $\mu \simeq 1$
cm$^2$/Vs and show that, within a range of temperatures, the mobility increases
with decreasing temperature. The experimental results further allow the
characterization of different aspects of the tetracene crystals. In particular,
the effects of both deep and shallow traps are clearly visible and can be used
to estimate their densities and characteristic energies. The results presented
in this paper show that the combination of $I$-$V$ measurements and time of
flight spectroscopy is very effective in characterizing several different
aspects of electronic transport through organic crystals.
