Bipolar resistive switching behavior of an amorphous Ge2Sb2Te5 thin films with a Te layer. Issue 14 (18th March 2015)

• Record Type: Journal Article
• Authors: Yoo, Sijung; Eom, Taeyong; Gwon, Taehong; Hwang, Cheol Seong
• Is Part Of: Nanoscale. Volume 7:Issue 14(2015)
• Page Start: 6340
• Page End: 6347
• Publication Date: 2015-03-18
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c5nr01361e
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : The mechanism of bipolar resistive switching (BRS) of amorphous Ge2 Sb2 Te5 (GST) thin films sandwiched between inert electrodes (Ti and Pt) was examined. Abstract : The mechanism of bipolar resistive switching (BRS) of amorphous Ge2 Sb2 Te5 (GST) thin films sandwiched between inert electrodes (Ti and Pt) was examined. Typical bipolar resistive switching behavior with a high resistance ratio (∼10 3 ) and reliable switching characteristics was achieved. High-resolution transmission electron microscopy revealed the presence of a conductive Te-filament bridging between the top and bottom electrodes through an amorphous GST matrix. The conduction mechanism analysis showed that the low-resistance state was semiconducting and dominated by band transport, whereas Poole–Frenkel conduction governed the carrier transport in the high-resistance state. Thus, the BRS behavior can be attributed to the formation and rupture of the semiconducting conductive Te bridge through the migration of the Te ions in the amorphous GST matrix under a high electric field. The Te ions are provided by the thin (∼5 nm) Te-rich layer formed at the bottom electrode interface.