2D and layered semiconductors are considered as promising electronic materials, particularly for applications that require high carrier mobility and efficient field‐effect switching combined with mechanical flexibility. To date, however, the highest mobility has been realized primarily at low carrier concentration. Here, it is shown that few‐layer/multilayer SnSe2 gated by a solution top gate combines very high room‐temperature electron mobility (up to 800 cm2 V−1s−1), along with large on‐off current ratios (>105) and a subthreshold swing below the thermodynamic limit (50 mV per decade) in field‐effect devices, at exceptionally large sheet carrier concentrations of ≈1013 cm−2. Observed mobility enhancements upon partial depletion of the channel point to near‐surface defects or impurities as the mobility‐limiting scattering centers. Under illumination, the resulting gap states give rise to gate‐controlled switching between positive and negative photoconductance. The results qualify SnSe2 as a promising layered semiconductor for flexible and wearable electronics, as well as for the realization of advanced approaches to photodetection.

中文翻译：

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高迁移率、高载流子密度 SnSe2 场效应晶体管，具有超低亚阈值摆幅和栅极控制光电导开关


2D 和多层半导体被认为是很有前途的电子材料，特别是对于需要高载流子迁移率和高效场效应切换以及机械灵活性的应用。然而，迄今为止，最高的迁移率主要是在低载流子浓度下实现的。在这里，表明由溶液顶栅门门控的少层/多层 SnSe2 结合了非常高的室温电子迁移率（高达 800 cm2 V-1s-1），以及大的开关电流比 （>105） 和低于热力学极限的亚阈值摆动（每十倍 50 mV），在场效应器件中，在极大的片状载流子浓度 ≈1013 cm-2 时。在通道部分耗尽时观察到的迁移率增强表明近表面缺陷或杂质是迁移率限制散射中心。在照明下，产生的间隙态会在正负光电导之间产生栅极控制的切换。结果使 SnSe2 成为一种很有前途的多层半导体，适用于柔性和可穿戴电子产品，以及实现先进的光检测方法。