  In this thesis I present a new type of brane - H-brane - where the role of
time in String Theory is considered as a primary concept in the search for
still unknown black hole physics. Using the basic tools of boundary conformal
field theory, we describe the H-branes both in the open and closed string
channels and examine how they fit naturally in the known D-brane moduli space.
In particular we compute their Ishibashi states and quantize the system using
the first order formalism. We find that the geometry associated to the target
null coordinates is non-commutative.
