2D layered van der Waals (vdW) atomic crystals are an emerging class of new materials that are receiving increasing attention owing to their unique properties. In particular, the dangling-bond-free surface of 2D materials enables integration of differently dimensioned materials into mixed-dimensional vdW heterostructures. Such mixed-dimensional heterostructures herald new opportunities for conducting fundamental nanoscience studies and developing nanoscale electronic/optoelectronic applications. This study presents a 1D ZnO nanowire (n-type)–2D WSe2 nanosheet (p-type) vdW heterojunction diode for photodetection and imaging process. After amorphous fluoropolymer passivation, the ZnO–WSe2 diode shows superior performance with a much-enhanced rectification (ON/OFF) ratio of over 106 and an ideality factor of 3.4–3.6 due to the carbon–fluorine (CF) dipole effect. This heterojunction device exhibits spectral photoresponses from ultraviolet (400 nm) to near infrared (950 nm). Furthermore, a prototype visible imager is demonstrated using the ZnO–WSe2 heterojunction diode as an imaging pixel. To the best of our knowledge, this is the first demonstration of an optoelectronic device based on a 1D–2D hybrid vdW heterojunction. This approach using a 1D ZnO–2D WSe2 heterojunction paves the way for the further development of electronic/optoelectronic applications using mixed-dimensional vdW heterostructures.
Bibliographical noteFunding Information:
Y.T.L., P.J.J., and J.H.H. contributed equally to this work. D.K.H. acknowledges the financial support from the Korea Institute of Science and Technology (KIST) Institution Program (Grant Nos. 2E27150 and 2E27160) and the National Research Foundation of Korea (NRF) (Grant No. 2017R1A2B2005640). This work was supported by the Cross-Ministry Giga KOREA Project of the Ministry of Science, ICT and Future Planning, Republic of Korea (GK17D0100, Development of Telecommunications Terminal with Digital Holographic Table-top Display) (M.-C.P.). S.I. acknowledges the financial support from NRF (NRL program: Grant No. 2017R1A2A1A05001278, SRC program: Grant No. 2017R1A5A1014862, vdWMRC center. The title of this manuscript was updated in December 15, 2017, following initial online publication.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics