隨著電子元件製作的不斷縮小，奈米導電通道僅由少數個原子所構成，因此訊號對於環境雜訊比更顯得重要。探索元件低頻雜訊(Low-frequency noise)的研究成為介觀尺度下重要的議題。林彥甫教授與日本合作者成為全球第一個探索新穎二維MoTe2材料低頻雜訊的研究團隊，此成果已發表於重要材料科學研究期刊，詳見Adv. Mater. 27, 6612 (2015)。
With the continuing shrinkage of transistor size and the development of nanotechnology, local interface imperfection and conducting channel defect can dramatically alter device performances and applications. Low-frequency noise is ubiquitous and dominates the signal-to-noise performance.
It is known that measurement of low frequency noise is taken as a non-destructive and highly sensitive indicator for exploring the fluctuation mechanism of defect trapping processes in solid-state devices, especially for nanoscale electronics. In this study, we investigated the low-frequency current fluctuations and determined the mechanism of electronic noise in layered MoTe2 transistors. Through a scrupulous analysis of the normalized dynamic-response signals, the 1/f dependence of the noise was observed in layered MoTe2 transistors in vacuum and followed the carrier number fluctuation model. In ambient conditions, the noise spectrum changed to a Lorentzian, possibly because of a large number of gas molecules absorbed at the chalcogen vacancies, enhancing the trapping and emission of carriers between two discrete energy states. Our study attempts to give a basic understanding of the charge transport mechanism of electric noise in atomically thin transition metal dichalcogenides under different environments and may stimulate the development of a new method of noise reduction via suitable surface passivation. This is the first report of the low-frequency noise characteristics of layered MoTe2 conducting channels.
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