We demonstrate improved terahertz (THz) modulation using thermally crystallized telluride (GeTe) GeTe is a that exhibits a nonvolatile, amorphous to crystalline at approximately 200 °C, as well as six orders of magnitude decreased In this study, amorphous GeTe were on substrates and then tested using THz time-domain The test samples, heated while collecting measurements, exhibited a gradual absorbance increase, an abrupt nonvolatile reduction at the transition temperature, followed by another gradual increase in absorbance. The transition temperature was verified by conducting similar thermal tests while monitoring THz transmittance modulation data were investigated between 10 and 110 cm−1 (0.3–3.3 THz). A peak modulation of approximately 99% was achieved at 2.3 THz with a 100 nm GeTe on a substrate. After isolating the and the crystalline GeTe (GeTe) absorbance contributions, the results showed THz modulations ranging from 88.5% to 91.5% that were attributed solely to the single layer of transitioned GeTe. These results strongly motivate using GeTe or other in THz filters, and metamaterial applications.
The measurments in this paper were collected with a TeraView THz-TDS
spectroscopy system equipped with a variable temperature sample holder.