  In this study, the effects of annealing under tellurium vapor have been
investigated for Fe$_{1.03}$Te$_{0.8}$Se$_{0.2}$ single crystals. The as-grown
crystal is not superconducting. After annealing it at 400 $^\circ$C for 250 h
in tellurium (Te) vapor, it shows metallic resistivity temperature dependence
below 150 K and a sharp superconducting transition at 13 K. The sample also
shows a full magnetic shielding effect at low temperatures. The improvement in
superconductivity has been attributed to the removal of excess Fe, which is
inevitably incorporated in the as-grown crystals, by the annealing.
