A Te precursor containing Te, a 15-group compound (for example, N) and/or a 14-group compound (for example, Si), a method of preparing the Te precursor, a Te-containing chalcogenide thin layer including the Te precursor, a method of preparing the thin layer; and a phase-change memory device. The Te precursor may be deposited at lower temperatures for forming a Te-containing chalcogenide thin layer doped with a 15-group compound (for example, N) and/or a 14-group compound (for example, Si). For example, the Te precursor may employ plasma enhanced chemical vapor deposition (PECVD) or plasma enhanced atomic layer deposition (PEALD) at lower deposition temperatures. The GST phase-change layer doped with a 15-group compound (for example, N) and/or a 14-group compound (for example, Si) formed by employing the Te precursor may have a decreased reset current, and thus when a memory device including the same is employed, its integration may be possible, and operation with higher capacity and/or higher speed may be possible.