Autor: |
Shackery, Iman, Pezeshki, Atiye, Park, Jae Young, Palanivel, Umadevi, Kwon, Hyeok Jae, Yoon, Hyong Seo, Im, Seongil, Cho, Jin Soo, Jun, Seong Chan |
Zdroj: |
Journal of Materials Chemistry C; 10/28/2018, Vol. 6 Issue 40, p10714-10722, 9p |
Abstrakt: |
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. [ABSTRACT FROM AUTHOR] |
Databáze: |
Complementary Index |
Externí odkaz: |
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