Fully Transparent p-MoTe2 2D Transistors Using Ultrathin MoOx/Pt Contact Media for Indium-Tin-Oxide Source/Drain

초록

Since transition metal dichalcogenide (TMD) semiconductors are found as 2D van der Waals materials with a discrete energy bandgap, many 2D-like thin field effect transistors (FETs) and PN diodes are reported as prototype electrical and optoelectronic devices. As a potential application of display electronics, transparent 2D FET devices are also reported recently. Such transparent 2D FETs are very few in report, yet no p-type channel 2D-like FETs are seen. Here, 2D-like thin transparent p-channel MoTe2 FETs with oxygen (O-2) plasma-induced MoOx/Pt/indium-tin-oxide (ITO) contact are reported for the first time. For source/drain contact, 60 s short O-2 plasma and ultrathin Pt-deposition processes on MoTe2 surface are sequentially introduced before ITO thin film deposition and patterning. As a result, almost transparent 2D FETs are obtained with a decent mobility of approximate to 5 cm(2) V-1 s(-1), a high ON/OFF current ratio of approximate to 10(5), and 70% transmittance. In particular, for normal MoTe2 FETs without ITO, O-2 plasma process greatly improves the hole injection efficiency and device mobility (approximate to 60 cm(2) V-1 s(-1)), introducing ultrathin MoOx between Pt source/drain and MoTe2. As a final device application, a photovoltaic current modulator, where the transparent FET stably operates as gated by photovoltaic effects, is integrated.

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