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 (O2) plasma-induced MoOx/Pt/indium-tin-oxide (ITO) contact are reported for the first time. For source/drain contact, 60 s short O2 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 ≈5 cm2 V−1 s−1, a high ON/OFF current ratio of ≈105, and 70% transmittance. In particular, for normal MoTe2 FETs without ITO, O2 plasma process greatly improves the hole injection efficiency and device mobility (≈60 cm2 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.
Bibliographical noteFunding Information:
Y.C. and J.H.P. contributed equally to this work. The authors acknowledge the financial support from NRF (NRL program: Grant No. 2017R1A2A1A05001278, SRC program: Grant No. 2017R1A5A1014862, vdWMRC Center), and Ministry of Trade, Industry and Energy (the Global Leading Technology Program: Grant No. 10042433-2012-11). J.H.P. acknowledges this research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1A6A3A11035872).
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics