Stable and scalable 1T MoS2 with low temperature-coefficient of resistance

Abstract

Monolithic realization of metallic 1T and semiconducting 2H phases makes MoS2 a potential candidate for future microelectronic circuits. A method for engineering a stable 1T phase from the 2H phase in a scalable manner and an in-depth electrical characterization of the 1T phase is wanting at large. Here we demonstrate a controllable and scalable 2H to 1T phase engineering technique for MoS2 using microwave plasma. Our method allows lithographically defining 1T regions on a 2H sample. The 1T samples show excellent temporal and thermal stability making it suitable for standard device fabrication techniques. We conduct both two-probe and four-probe electrical transport measurements on devices with back-gated field effect transistor geometry in a temperature range of 4 K to 300 K. The 1T samples exhibit Ohmic current-voltage characteristics in all temperature ranges without any dependence to the gate voltage, a signature of a metallic state. The sheet resistance of our 1T MoS2 sample is considerably lower and the carrier concentration is a few orders of magnitude higher than that of the 2H samples. In addition, our samples show negligible temperature dependence of resistance from 4 K to 300 K ruling out any hoping mediated or activated electrical transport.

Longitudinal unzipping of 2D transition metal dichalcogenides

“…10A, B). The resistivity of MoS 2 NRs is comparable to the 1T′ MoS 2 nanosheets prepared by hydrothermal synthesis (10 −1 Ωcm) and chemical exfoliation (10 1 -10 −2 Ωcm) but higher than those prepared by solid-state reaction (10 −3 Ωcm) and exfoliation with high-power forminggas microwave plasma (8.6 × 10 −5 Ωcm) [24][25][26][27][28] . The relatively low electron mobility of MoS 2 NRs (2.7 × 10 −2 cm 2 V −1 s −1 ) suggests the presence of defects and vacancies as well as edge sites 6,29 .…”

Molybdenum Dichalcogenide Cathodes for Aluminum‐Ion Batteries

“…In addition, we compared the Raman spectra of pristine and charged cathodes to detect shifts in vibrational modes shown in Figure . Yang et al and Sharma et al have reported that and are the most intense vibrational modes for molybdenum dichalcogenides . Peaks corresponding to and modes for (Figure a) are prominent at 384.6 and 410.2 cm −1 , respectively.…”

The Stability of Metallic MoS2 Nanosheets and Their Property Change by Annealing

“…It provides one of the easy and nondestructive ways to directly monitor the transition process of MoS 2 . Several groups have confirmed the formation of 1T MoS 2 from the emergence of new Raman shifts associated with the phonon modes of 1T MoS 2 [21,24,28,29,30]. Therefore, the Raman data clearly provide the key evidence of phase transition in MoS 2 nanosheets.…”