Solution Processing for Lateral Transition Metal Dichalcogenides Homojunction from Polymorphic Crystal

J. Wu, J. Peng, Y. Zhou, Y. Lin, X. Wen, J. Wu, Y. Zhao, Y. Guo, C. Wu and Y. Xie

J. Am. Chem. Soc., Just Accepted (2018)
Homojunctions comprised of transition metal dichalcogenides (TMD) polymorphs are attractive building blocks for next-generation two-dimensional (2D) electronic circuitry. However, the synthesis of such homojunctions, which usually involves elaborate manipulation at nanoscale, still remains a great challenge. Herein, we demonstrated a solution-processing strategy to successfully harvest lateral semiconductor-metal homojunctions with high yield. Specially, through precisely controlled lithiation process, precursors of polymorphic crystal arranged with 1T-2H domains were successfully achieved. A programmed exfoliation procedure was further employed to orderly laminate each phase in the polymorphic crystal, thus leading to 1T-2H TMD homojunction monolayers with size up to tens of micrometers. Moreover, the atomically sharp boundaries and superior band alignment improved the device based on the semiconductor-metal homojunction with 50% decrease of electric field strength required in the derivation of state transition. We anticipate that solution processing based on programmed exfoliation would be a powerful tool to produce new configurations of 2D nanomaterials.