Recently, two-dimensional (2D) transition metal dichalcogenide (TMDC) semiconductors as van der Waals (vdW) materials have attracted much attention from researchers. Among many 2D TMDC materials, a few layer-thin molybdenum disulfide (MoS2) and tungsten diselenide (WSe2) have been most intensively studied respectively as 2D n- and p-type semiconductors. Here, we have fabricated vertical vdW heterojunction n-MoS2/p-WSe2 diode with a few tens nm-thick layers by using vertically-sandwiched ohmic terminals, so that no quasi neutral region may exist between two terminals. As a result, we obtained high photo responsivity at zero volt without any electric power, and it appears comparable to those of commercially-optimized SiPN diode. Photo-voltage output of 0.3 V was easily obtained from our vdWPN diode as open circuit voltage, and can be doubled up to 0.6 Vby using two PN diodes. These beneficial photovoltaic results from vdWPN diode were directly applied to PV switching dynamics and transistor photo gating, for the first time. We regard that our vdW n-MoS2/p-WSe2 heterojunction diode could maximize its photovoltaic energy benefits with optimized TMDC thicknesses.
Bibliographical noteFunding Information:
J A and P J J have contributed equally to this research. The authors were supported by NRF (NRL program, Grant No. 2014R1A2A1A01004815), Creative Materials Discovery Program through NRF funded by the Ministry of Science, ICT and Future Planning (Grant No. 2015M3D1A1068061), the Korea Evaluation Institute of Industrial Technology (Grant No. 10042433-2012-11), the Yonsei University (Futureleading Research Initiative of 2014, Grant No. 2014-22-0168), and Brain Korea 21 plus Program.
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All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering