We propose a simple method of making defects in two-dimensional photon
ic crystals by radius modification and analyzed energy levels of such
defects obtained by the supercell method. In a triangular lattice of t
he semiconductor-rods-in-air structure, it was found that both a singl
e sharp acceptor level and a single sharp donor level can be achieved
with a defect bandwidth of about 5% of the band gap for E-polarized in
-plane waves.