A gate-free MoS2 phototransistor assisted by ferroelectrics
A gate-free MoS2 phototransistor assisted by ferroelectrics
复制标题
铁电体辅助的无栅MoS_2光电晶体管
DOI：
10.1088/1674-4926/40/9/092002
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发表时间：
2019-09-01
影响因子：
5.1
通讯作者：
Chu, Junhao
中科院分区：
文献类型：
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作者：
Wu, Shuaiqin;Wu, Guangjian;Chu, Junhao
在过去的几十年里，过渡金属二卤代化合物(TMD)以其独特的性质在光电检测中受到了特别的关注。作为TMDs的重要成员之一，MoS2已被单独或与石墨烯、离子液体、铁电材料等材料复合制成光电探测器。在这里，我们报道了一种与有机铁电材料聚(偏氟乙烯-三氟乙烯)(P(VDF-TrFE))相结合的无栅MoS_2光电晶体管。在该装置中，P(VDF-TrFE)中的剩余极化场是通过压电力显微镜(PFM)的正偏压或负偏压获得的，可以使偶极子从无序变为同向。然后，可以将MoS2通道维持在具有向下极化场调制的累加状态和具有向上极化场调制的耗尽状态。此外，P(VDF-TrFE)将MoS2与周围环境中的氧气和水分子分离，从而实现了更清洁的表面状态。作为光电探测器，获得了10~(-11)A的超低暗电流、大于10~4的通断比和120μ的快速光响应时间S。这项工作提供了一种新的方法来制作铁电域辅助的高性能光电晶体管，它可以在不需要栅极的情况下工作，并在超低功耗应用中显示出巨大的潜力。
During the past decades, transition metal dichalcogenides (TMDs) have received special focus for their unique properties in photoelectric detection. As one important member of TMDs, MoS2 has been made into photodetector purely or combined with other materials, such as graphene, ionic liquid, and ferroelectric materials. Here, we report a gate-free MoS2 phototransistor combined with organic ferroelectric material poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)). In this device, the remnant polarization field in P(VDF-TrFE) is obtained from the piezoelectric force microscope (PFM) probe with a positive or negative bias, which can turn the dipoles from disorder to be the same direction. Then, the MoS2 channel can be maintained at an accumulated state with downward polarization field modulation and a depleted state with upward polarization field modulation. Moreover, the P(VDF-TrFE) segregates MoS2 from oxygen and water molecules around surroundings, which enables a cleaner surface state. As a photodetector, an ultra-low dark current of 10–11 A, on/off ration of more than 104 and a fast photoresponse time of 120 μs are achieved. This work provides a new method to make high-performance phototransistors assisted by the ferroelectric domain which can operate without a gate electrode and demonstrates great potential for ultra-low power consumption applications.