Few-layered α-MoTe2 Schottky junction for a high sensitivity chemical-vapour sensor

Iman Shackery, Atiye Pezeshki, Jae Young Park, Umadevi Palanivel, Hyeok Jae Kwon, Hyong Seo Yoon, Seongil Im, Jin Soo Cho, Seong Chan Jun

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7 Citations (Scopus)

Abstract

For the first time, we connect in series two α-MoTe2-based Schottky diodes (SDs) to form a back-to-back diode using the micromechanical exfoliation method. The α-MoTe2 SD exhibits an excellent ON/OFF current ratio of ∼103 and low-voltage operation at 5 V. Although various studies of α-MoTe2 field-effect transistors (FETs), phototransistors, and p-n diodes have been reported, there are no reported theoretical or experimental studies of α-MoTe2 for chemical sensing. Here, we experimentally assess the SD and a FET for gas sensing with exposure to different concentrations of NO2 and NH3. Interestingly, the α-MoTe2 SD showed a faster response and recovery time to NH3 and NO2 than the α-MoTe2 FET owing to its Schottky junction, which is favorable for detecting the Schottky-barrier height change due to gas exposure. The SD showed a fast response of 15 s when exposed to 70-ppb NO2 and ∼1 s when exposed to 70 ppb NH3 with a relative resistance change of 13% and 101%, respectively, and this was attributed to its physisorption process. In addition, our results are confirmed by density functional theory. The α-MoTe2-based SD is shown to be promising as an electrical rectifier or as a gas sensor owing to its simple and inexpensive electrical circuitry and excellent performance, including its low voltage, high ON/OFF current ratio and good sensitivity to toxic gases at room temperature. Further, it may be suitable for diverse uses, such as chemical and biosensing applications.

Original languageEnglish
Pages (from-to)10714-10722
Number of pages9
JournalJournal of Materials Chemistry C
Volume6
Issue number40
DOIs
Publication statusPublished - 2018

Bibliographical note

Funding Information:
This research was supported by Nano-Material Technology Development Program (NRF-2017M3A7B4041987) and the Korean Government (MSIP) (No. 2015R1A5A1037668) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning.

Publisher Copyright:
© The Royal Society of Chemistry.

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Chemistry

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