2D layered heterostructures have attracted intensive interests due to their unique optical, transport, and interfacial properties. The laterally stitched heterojunction based on dissimilar 2D transition metal dichalcogenides forms an intrinsic p–n junction without the necessity of applying an external voltage. However, no scalable processes are reported to construct the devices with such lateral heterostructures. Here, a scalable strategy, two-step and location-selective chemical vapor deposition, is reported to synthesize self-aligned WSe2–MoS2 monolayer lateral heterojunction arrays and demonstrates their light-emitting devices. The proposed fabrication process enables the growth of high-quality interfaces and the first successful observation of electroluminescence at the WSe2–MoS2 lateral heterojunction. The electroluminescence study has confirmed the type-I alignment at the interface rather than commonly believed type-II alignment. This self-aligned growth process paves the way for constructing various 2D lateral heterostructures in a scalable manner, practically important for integrated 2D circuit applications.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: M.-Y.L. and J.P. contributed equally to this work. M.-Y.L., J.-K.H., and L.-J.L. acknowledge support from the King Abdullah University of Science and Technology (KAUST) and Academia Sinica. T.T. acknowledges support from JSPS-KAKENHI (Grant Numbers JP17H01069, JP16K13618, JP15K21721, JP26102012, and JP25000003). J.P. was supported by JSPS-KAKENHI (Grant Number JP17H06736). K.M. was partially supported by JSPS-KAKENHI (Grant Numbers 26107522, JP16H00910, and JP16H06331) and the Asahi glass foundation. Y.M. was partially supported by JSPS-KAKENHI (Grant Numbers JP16H00911, JP15K13337, JP15H05408, and JP17K19055, by JST CREST(Grant Number JPMJCR16F3), and by the Murata Science Foundation.