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High transmittance contrast in amorphous to hexagonal phase of Ge2Sb2Te5: Reversible NIR-window

IR@NPL: CSIR-National Physical Laboratory, New Delhi


Field	Value

Title	High transmittance contrast in amorphous to hexagonal phase of Ge2Sb2Te5: Reversible NIR-window

Creator	Singh, Palwinder Singh, A. P. Kanda, Neetu Mishra, Monu Gupta, Govind Thakur, Anup

Subject	Applied Physics/Condensed Matter

Description	Ge2Sb2Te5 (GST) is one of the best phase change materials because of its splendid set of properties, viz., high thermal stability, fast crystallization speed, good endurance, scalability, and reliability. Phase transition [amorphous -> face centered cubic (fcc) -> hexagonal close packed (hcp)] of GST thin films with annealing was studied using X-ray diffraction. Thin films in amorphous, fcc, and hcp phases are highly, medium, and negligible transparent in the near infra-red region, respectively. The optical transmission in amorphous, fcc, and hcp phases is similar to 92%, similar to 46%, and similar to 2%, respectively, at the wavelength of 2740 nm. At 2740 nm, a high transmission contrast (similar to 90%) is observed with phase transition from the amorphous to hcp phase. By utilizing large transmission contrast, it is demonstrated that GST can be availed as a potential candidate for reversible near infra-red-window. The sharp change in optical transmission with phase transition can be understood from the change in density of states in the valence band.

Publisher	AIP Publishing

Date	2017-12-25

Type	Article PeerReviewed

Format	application/pdf

Identifier	http://npl.csircentral.net/2739/1/High%20transmittance%20contrast.pdf Singh, Palwinder and Singh, A. P. and Kanda, Neetu and Mishra, Monu and Gupta, Govind and Thakur, Anup (2017) High transmittance contrast in amorphous to hexagonal phase of Ge2Sb2Te5: Reversible NIR-window. Applied Physics Letters, 111 (26). 261102-1-261102-4. ISSN 0003-6951

Relation	http://npl.csircentral.net/2739/