Mixed-Phase Crystallization and Resonance Tuning in Sn-Incorporated GST Thin Films: Experimental Study with THz...

Area of Science:

• Materials Science
• Nanotechnology
• Photonics

Background:

• Germanium-Antimony-Tellurium (GST) is a phase-change material with tunable optical properties.
• Terahertz (THz) sensing requires materials with significant dielectric contrast between amorphous and crystalline states.

Purpose of the Study:

• To investigate the effect of tin (Sn) incorporation on the properties of Ge₂Sb₂Te₅ (GST) thin films.
• To evaluate the potential of Sn-incorporated GST for reconfigurable terahertz (THz) device applications.

Main Methods:

• Thin films prepared using DC magnetron cosputtering.
• Composition and phase analyzed by energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS).
• Terahertz time-domain spectroscopy (THz-TDS) used to measure optical properties and dielectric contrast.

Main Results:

• Sn incorporation modifies GST crystallization, forming mixed SnTe and SnSb phases.
• Phase transformation occurs at lower thermal energy in Sn-incorporated GST.
• Enhanced dielectric contrast and improved modulation efficiency observed in Sn-GST films compared to pure GST.
• Simulations of split-ring resonator (SRR) metasurfaces showed improved performance with Sn-GST.

Conclusions:

• Sn-incorporated GST offers a tunable platform for terahertz (THz) sensing.
• This material enables more energy-efficient and reconfigurable THz devices.
• Sn-GST is a promising candidate for next-generation THz technologies.