2020年第67回応用物理学会春季学術講演会

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一般セッション(口頭講演)

17 ナノカーボン » 17.3 層状物質

[12p-A401-1~6] 17.3 層状物質

2020年3月12日(木) 16:15 〜 17:45 A401 (6-401)

佐藤 信太郎(富士通研)

16:30 〜 16:45

[12p-A401-2] [Highlight]Chemically tuned p- and n-type WSe2 monolayers with higher carrier mobility for advanced electronics

〇(D)HyunGoo Ji1、Pablo Solis-Fernandez2、Daisuke Yoshimura3、Mina Maruyama4、Takahiko Endo5、Yasumitsu Miyata5、Susumu Okada4、Hiroki Ago1,2 (1.Interdisciplinary Graduate School of Engineering Sciences, Kyushu University、2.Global Innovation Center, Kyushu University、3.Kyushu Synchrotron Light Research Center、4.Graduate School of Pure and Applied Sciences, University of Tsukuba、5.Department of Physics, Tokyo Metropolitan University)

キーワード:Chemical doping, Complementary inverter, p-n junction

Semiconducting transition metal dichalcogenides (TMDCs), such as WSe2 and MoS2, have been attracting great interest due to their superior and unique properties. Although both p- and n-type materials are required for their application in advanced electronics, most of semiconducting TMDCs exhibit n-type or ambipolar behavior. Therefore, several approaches have been reported to control the electrical polarity of semiconducting TMDCs, such as substitutional doping of transition metals and metal nanoparticle deposition. However, these methods have critical disadvantages, such as carrier scattering and photoluminescence quenching. As an alternative, chemical doping can be a promising method. Although the usefulness of chemical doping has been demonstrated, the controlled p- and n-type doping with a single TMDC material has not been reported so far.
In this work, we demonstrate the doping of CVD grown-WSe2 for selective conversion from ambipolar to p- or n-type semiconductors. This was done by using 4-nitrobenzenediazonium tetrafluoroborate (4-NBD) and diethylene triamine (DETA) molecules as p- or n-type dopants, respectively. After the doping process, WSe2 showed clear p- or n-type transport properties and the effective carrier mobility showed significant increase up to 103~104 times (Fig. 1). To demonstrate utilization of our chemically doped p- and n-type WSe2, a complementary metal-oxide-semiconductor inverter was fabricated which showed extremely low power consumption and high voltage gain (~10) (Fig. 2). Moreover, a p-n junction was fabricated within single WSe2 grain by spatially controlled doping technique, and it showed clear rectification behavior as well as optical response under laser illumination (Fig. 3).