Wang Shunfeng, Zhao Weijie, Giustiniano Francesco, Eda Goki
Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542.
Phys Chem Chem Phys. 2016 Feb 14;18(6):4304-9. doi: 10.1039/c5cp07194a.
We report on the p-type doping effect of oxygen and ozone molecules on mono- and few-layer WSe2 and MoSe2 field effect transistors. We show that adsorption of oxygen and ozone under ambient conditions results in subtantial doping and corresponding enhancement in the hole conductivity of the devices. Ozone-induced doping is found to be rapid and efficient, saturating within minutes of exposure whereas oxygen-induced doping occurs over a period of days to reach the equivalent level of doping. Our observations reveal that the water adlayer on the material surface plays a crucial role in solubilizing oxygen and ozone and in forming a redox couple with a large chemical potential.
我们报道了氧分子和臭氧分子对单层及少数层WSe2和MoSe2场效应晶体管的p型掺杂效应。我们表明，在环境条件下吸附氧和臭氧会导致显著的掺杂，并相应提高器件的空穴电导率。发现臭氧诱导的掺杂迅速且有效，在暴露几分钟内就达到饱和，而氧诱导的掺杂则需要几天时间才能达到等效的掺杂水平。我们的观察结果表明，材料表面的水吸附层在溶解氧和臭氧以及形成具有大化学势的氧化还原对方面起着关键作用。
