Strongly correlated oxides, such as vanadium dioxide that undergoes a sharp metal-insulator transition when triggered by different stimuli, are of high relevance for novel electronic devices. In this work, we show the variation in threshold voltage of memristor behavior with systematic doping of tungsten (W) in VO2 crystals grown by the vapor transport method. Chemical doping effects on metal insulator transition are further correlated with Raman spectroscopy studies and differential scanning calorimetry studies. Furthermore, bi-polar threshold switching of VO2 memristor behavior is demonstrated in VO2 microcrystals with different contents of W. Threshold voltage for electrical triggering in W doped VO2 is reduced to about 0.547 V from 2.27 V of undoped VO2.
MoTe2 garnered much attention among 2D materials due to stable polymorphs with distinctive structural and electronic properties. Among the polymorphs, 1T’-MoTe2 in bulk form is type – II Weyl semimetal while, in monolayer form is a quantum spin Hall insulator. Thus, it is suitable for a wide variety of applications. Nevertheless, 1T’-MoTe2 degrades within a few hours when exposed to the atmosphere and causes hindrances in device fabrication. Here the degradation kinetics of CVD-synthesized 1T’-MoTe2 was investigated using Raman spectroscopy, XPS, and microscopic characterizations. The degradation rate of as-grown 1T’-MoTe2 obtained was 9.2 x 10-3 min-1. Further, we prevented the degradation of 1T’-MoTe2 by introducing a thin coating of S that encapsulates the flakes. 1T’-MoTe2 flakes showed stability for several days when covered using Sulphur, indicating 25 times enhanced structural stability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.