Chalcogen-containing compound, its preparation method and thermoelectric element comprising the same

A chalcogen-containing compound represented by the following Chemical Formula 1:

• V1-xMxSn4-yPbyBi2Se7-zTez [Chemical Formula 1]
• wherein, in the above Formula 1, V is a vacancy, M is an alkali metal, x is greater than 0 and less than 1, y is greater than 0 and less than 4, and z is greater than 0 and less than or equal to 1,
• wherein the chalcogen-containing compound has a face-centered cubic crystal lattice structure,
• the Se is filled in an anion site of the face-centered cubic lattice structure,
• the Sn, Pb, and Bi are filled in a cation site of the face-centered cubic lattice structure,
• the Pb is substituted by replacing a part of the Sn,
• the Te is substituted by replacing a part of the Se,
• the M is filled in at least some of vacant sites excluding the sites filled with Sn, Pb, Bi, Se, and Te in the face-centered cubic lattice structure, and
• the V is a vacant site of the remaining cationic sites.