Kim Sun Jun, Park Jae Young, Yoo SangHyuk, Umadevi Palanivel, Lee Hyunpyo, Cho Jinsoo, Kang Keonwook, Jun Seong Chan
Department of Mechanical Engineering, Yonsei University, Seoul, 120-749, Republic of Korea.
Department of Computer Engineering, Gachon University, Gyeonggi-do, 461-701, Republic of Korea.
Nanoscale Res Lett. 2018 Sep 4;13(1):265. doi: 10.1186/s11671-018-2652-9.
Over the past few years, two-dimensional materials have gained immense attention for next-generation electric sensing devices because of their unique properties. Here, we report the carrier transport properties of MoS Schottky diodes under ambient as well as gas exposure conditions. MoS field-effect transistors (FETs) were fabricated using Pt and Al electrodes. The work function of Pt is higher than that of MoS while that of Al is lower than that of MoS. The MoS device with Al contacts showed much higher current than that with Pt contacts because of its lower Schottky barrier height (SBH). The electrical characteristics and gas responses of the MoS Schottky diodes with Al and Pt contacts were measured electrically and were simulated by density functional theory calculations. The theoretically calculated SBH of the diode (under gas absorption) showed that NO molecules had strong interaction with the diode and induced a negative charge transfer. However, an opposite trend was observed in the case of NH molecules. We also investigated the effect of metal contacts on the gas sensing performance of MoS FETs both experimentally and theoretically.
在过去几年中，二维材料因其独特性能而在下一代电传感设备方面受到了极大关注。在此，我们报告了在环境条件以及气体暴露条件下MoS肖特基二极管的载流子输运特性。使用Pt和Al电极制造了MoS场效应晶体管（FET）。Pt的功函数高于MoS，而Al的功函数低于MoS。具有Al接触的MoS器件由于其较低的肖特基势垒高度（SBH）而显示出比具有Pt接触的器件高得多的电流。对具有Al和Pt接触的MoS肖特基二极管的电学特性和气体响应进行了电学测量，并通过密度泛函理论计算进行了模拟。二极管（在气体吸收下）的理论计算SBH表明，NO分子与二极管有强烈相互作用并诱导负电荷转移。然而，在NH分子的情况下观察到相反的趋势。我们还通过实验和理论研究了金属接触对MoS FET气体传感性能的影响。
