A high performance electroformed single-crystallite VO threshold switch

• Published in: Nanoscale Vol. 11; no. 45; pp. 227 - 2278
• Main Authors: Zhou, Xin, Gu, Deen, Li, Yatao, Qin, Haoxin, Jiang, Yadong, Xu, Jimmy
• Format: Journal Article
• Language: English
• Published: 21.11.2019
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c9nr08364b

Threshold switches (TSs) are an effective approach for resolving the sneak path problem within a memristor array. VO 2 is a promising material for fabricating high-performance TSs. Here we report a single crystal VO 2 -based TS device with high switching performance. The single crystal monoclinic VO 2 channel is obtained by electroforming in a composite vanadium oxide film consisting of VO 2 , V 2 O 5 and V 3 O 7 . The formation mechanism on single crystal VO 2 is thoroughly investigated by means of X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. The single crystal VO 2 -based TS device exhibits better switching performance than the polycrystalline monoclinic VO 2 counterpart. The TS device based on a single crystal channel with the (2&cmb.macr;11) orientation exhibits a steep turn-on voltage slope of <0.5 mV dec −1 , a fast switching speed of 23 ns, an excellent endurance over 10 9 cycles, a high I on / I off ratio of 143 and a low sample-to-sample variance. The enhanced switching performance originates from the single crystal feature and specified crystal orientation. We investigated the threshold switching characteristics of an electroformed single crystal VO 2 channel, it exhibits a high I on / I off ratio of 143, a steep turn-on voltage slope of <0.5 mV dec −1 and a fast switching speed of 23 ns.