Disclosed herein is a copolymer, which may include side chains which may
decrease the surface energy of an insulating layer, thereby improving the
alignment of a semiconductor material, and side chains including
photoreactive functional groups having an increased degree of
cross-linking, thereby improving the characteristics of an organic thin
film transistor manufactured using the same, an organic insulating layer
composition including the copolymer, an organic insulating layer, an
organic thin film transistor, an electronic device including the same and
methods of fabricating the same. According to the copolymer of example
embodiments, the surface energy of an insulating layer may be decreased,
so that the alignment of a semiconductor material may be improved,
thereby improving the threshold voltage and charge mobility and
decreasing the generation of hysteresis at the time of driving the
transistor.