Visualized charge transfer processes in monolayer composition-graded WS2xSe2(1-x) lateral heterojunctions via ultrafast microscopy mapping

Published on 2018-06-08T14:58:33Z (GMT) by
Two-dimensional transitional metal dichalcogenides (TMDCs) based lateral heterojunctions have emerged as appealing and intriguing materials for applications in the next generation flexible nanoelectronics. Though it is hard to be fabricated with mechanical exfoliation, lateral heterojunctions can be synthetized by the chemical vapor deposition (CVD) process. The construction of depletion region near the in-plane interline brings rich opto-electrical dynamics, which is essential for future applications. Due to the synchronous requirement of spatial and time resolution, the study of lateral heterojunction dynamics remains a challenging issue. Herein, we have synthetized monolayer spatial composition-graded WS2xSe2(1-x) lateral heterojunctions and investigated the ultrafast photocarrier dynamics after laser excitation. By means of the spatiotemporal femtosecond transient absorption (TAS) spectroscopy platform, we have visualized the charge transfer (CT) processes across the depletion reigon, which results in not only the space modulation of the interline, but also significant broadening of rising edge on the outer ring region. More importantly, the carrier lifetime is extraordinarily extended by over 3 times near the interline. All these results unveil its great potential in designing future low cost logic devices and ultrafast optical applications.

Cite this collection

Hao, Hao; Xu, Zhongjie; Jiang, Tian; We, Ke; Li, Han; Zheng, Xin; et al. (2018): Visualized charge transfer processes in monolayer composition-graded WS2xSe2(1-x) lateral heterojunctions via ultrafast microscopy mapping. The Optical Society. Collection.