A highly sensitive chemical gas detecting transistor based on highly crystalline CVD-grown MoSe2 films

• Published in: Nano research 2017-06, Vol.10 (6), p.1861-1871
• Main Authors: Baek, Jongyeol, Yin, Demin, Liu, Na, Omkaram, Inturu, Jung, Chulseung, Im, Healin, Hong, Seongin, Kim, Seung Min, Hong, Young Ki, Hur, Jaehyun, Yoon, Youngki, Kim, Sunkook
• Format: Article
• Language: English
• Subjects: Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Carrier transport; Chemical sensors; Chemical vapor deposition; Chemistry and Materials Science; Computer simulation; Condensed Matter Physics; CVD; Electronic devices; Electronic equipment; Fabrication; Field effect transistors; Gas sensors; Materials Science; Nanotechnology; Nitrogen dioxide; Quantum transport; Research Article; Semiconductor devices; Sensitivity; Sensors; Surface chemistry; Time response; Transistors; Valence band; 化学气相沉积; 敏感; 材料生长; 气体传感器; 气体检测; 薄膜晶体管; 超高灵敏度
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-016-1291-7

Layered semiconductors with atomic thicknesses are becoming increasingly important as active elements in high-performance electronic devices owing to their high carrier mobilities, large surface-to-volume ratios, and rapid electrical responses to their surrounding environments. Here, we report the first implementation of a highly sensitive chemical-vapor-deposition-grown multilayer MoSe2 field-effect transistor （FET） in a NO2 gas sensor. This sensor exhibited ultra-high sensitivity （S = ca. 1,907 for NO2 at 300 ppm）, real-time response, and rapid on-off switching. The high sensitivity of our MoSe2 gas sensor is attributed to changes in the gap states near the valence band induced by the NO2 gas absorbed in the MoSe2, which leads to a significant increase in hole current in the off-state regime. Device modeling and quantum transport simulations revealed that the variation of gap states with NO2 concentration is the key mechanism in a MoSe2 FET-based NO2 gas sensor. This comprehensive study, which addresses material growth, device fabrication, characterization, and device simulations, not only indicates the utility of MoSe2 FETs for high-performance chemical sensors, but also establishes a fundamental understanding of how surface chemistry influences carrier transport in layered semiconductor devices.