  This article reviews recent experimental investigations on two binary
Fe-chalcogenides: FeSe and Fe$_{1+y}$Te. The main focus is on synthesis, single
crystal growth, chemical composition, as well as on the effect of excess iron
on structural, magnetic, and transport properties of these materials. The
structurally simplest Fe-based superconductor Fe$_{1+x}$Se with a critical
temperature $T_c \approx$ 8.5 K undergoes a tetragonal to orthorhombic phase
transition at a temperature $T_s \approx$ 87 K. No long-range magnetic order is
observed down to the lowest measured temperature in Fe$_{1+x}$Se. On the other
hand, isostructural Fe$_{1+y}$Te displays a complex interplay of magnetic and
structural phase transitions in dependence on the tuning parameter such as
excess amount of Fe or pressure, but it becomes a superconductor only when Te
is substituted by a sufficient amount of Se. We summarize experimental evidence
for different competing interactions and discuss related open questions.
