Hysteresis of Transfer Characteristics in Field-Effect Transistors with a Molybdenum Disulfide Channel
Hysteresis of Transfer Characteristics in Field-Effect Transistors with a Molybdenum Disulfide Channel
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DOI：
10.11605/j.pnrs.201701008
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发表时间：
2017-10
期刊：
影响因子：
--
通讯作者：
Y. Shimazu
中科院分区：
文献类型：
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作者：
Y. Shimazu
近年来对单层和多层二硫化钼（MoS2）器件的研究揭示了其作为新型半导体器件的良好特性。本文报道了环境气体对MoS2背门多层场效应晶体管传输特性中迟滞的影响，并观察到在1K以下存在异常大的迟滞。不同气体（氧、氮、空气和不同相对湿度的氮）之间的比较表明，水分子作为电荷捕获（主要是空穴捕获）中心是迟滞的主要原因。尽管在室温下抽出环境气体超过24小时后，滞后仍然存在，但当器件冷却到240 K时，滞后消失，这表明在这些适度低温下电荷捕获/脱陷的时间常数有相当大的增加。在1k以下，我们首次观察到一个异常大的滞后，这不是归因于电荷捕获。我们假设这种迟滞是由于电子在接触处通过肖特基势垒的量子隧穿缓慢注入造成的。磁滞的大小随栅极电压扫描速率的增加而增大，这与极慢注入电子的可能性是一致的。
Recent studies on singleand multilayer molybdenum disulfide (MoS2) devices have revealed their promising characteristics as novel semiconductor devices. Here, we report the effects of environmental gases on the hysteresis in the transfer characteristics and observation of an anomalously large hysteresis below 1K for back-gated multilayered MoS2 field-effect transistors. Comparisons between different gases (oxygen, nitrogen, air, and nitrogen with varying relative humidities) revealed that water molecules acting as charge-trapping (dominantly hole-trapping) centers are the main cause of hysteresis. While the hysteresis persisted even after pumping out the environmental gas for longer than 24 h at room temperature, it disappeared when the device was cooled to 240 K, suggesting a considerable increase in the time constant of the charge trapping/detrapping at these modestly low temperatures. Below 1 K, we observed for the first time an anomalously large hysteresis, which is not attributed to charge trapping. We hypothesize that this hysteresis results from the slow injection of electrons via quantum tunneling through the Schottky barrier at the contacts. The size of the hysteresis increased with increase in the scan rate of the gate voltage, which is consistent with the possibility of very slow injection of electrons.