Environmental Effects on Hysteresis of Transfer Characteristics in Molybdenum Disulfide Field-Effect Transistors.
Environmental Effects on Hysteresis of Transfer Characteristics in Molybdenum Disulfide Field-Effect Transistors.
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DOI：
10.1038/srep30084
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发表时间：
2016-07-20
影响因子：
4.6
通讯作者：
Takahashi M
中科院分区：
文献类型：
--
作者：
Shimazu Y;Tashiro M;Sonobe S;Takahashi M
二硫化钼（MoS 2）在纳米级电子和光子学应用中受到广泛关注。为了探索MoS 2基场效应晶体管的本征特性并提高其性能，需要深入了解环境气体和电极接触电阻等非本征效应。在这里，我们报告的背栅多层二硫化钼场效应晶体管的传输特性的环境气体的影响。不同的气体（氧气，氮气，空气和氮气与不同的相对湿度）之间的比较表明，水分子作为电荷捕获中心的传输特性的滞后的主要原因。虽然滞后持续，即使在室温下抽出的环境气体超过10小时后，它消失时，该设备被冷却到240 K，这表明在这些适度的低温度下的电荷捕获/脱陷的时间常数相当大的增加。在没有表面钝化的情况下，在容易达到的温度范围内抑制滞后或不稳定性对于该系统的器件应用是非常有利的。在转移曲线中阈值电压的湿度依赖性表明，水分子主要作为空穴捕获中心。还观察到的通态电流对氧压的强烈依赖性。
Molybdenum disulfide (MoS2) has recently received much attention for nanoscale electronic and photonic applications. To explore the intrinsic properties and enhance the performance of MoS2-based field-effect transistors, thorough understanding of extrinsic effects such as environmental gas and contact resistance of the electrodes is required. Here, we report the effects of environmental gases on the transport properties of back-gated multilayered MoS2 field-effect transistors. Comparisons between different gases (oxygen, nitrogen, and air and nitrogen with varying relative humidities) revealed that water molecules acting as charge-trapping centers are the main cause of hysteresis in the transfer characteristics. While the hysteresis persisted even after pumping out the environmental gas for longer than 10 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. The suppression of the hysteresis or instability in the easily attainable temperature range without surface passivation is highly advantageous for the device application of this system. The humidity dependence of the threshold voltages in the transfer curves indicates that the water molecules dominantly act as hole-trapping centers. A strong dependence of the on-state current on oxygen pressure was also observed.