Tunable ultrafast electron transfer in WSe-graphene heterostructures enabled by atomic stacking order.

Nanoscale

State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-intense Laser Science, Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences (CAS), Shanghai 201800, China.

Published: May 2022


Category Ranking

98%

Total Visits

921

Avg Visit Duration

2 minutes

Citations

20

Article Abstract

Efficient interfacial light-electric interconversion in van der Waals (vdW) heterostructures is crucial for their optoelectronic applications. However, an in-depth understanding of the necessary process for device operation, namely interfacial charge transfer (CT), has thus far remained elusive. In this study, by using photon energy-dependent transient THz spectroscopy, we complementarily investigate the interfacial CT process in heterostructures comprising monolayers of WSe and graphene with varying stacking orders on a sapphire substrate. We observe that the CT mechanism of the sub-A-exciton excitation is different from that of the above-A-exciton excitation. Notably, the CT process occurs a photo-thermionic emission for sub-A-exciton excitations and a direct electron (or hole) transfer for above-A-exciton excitations. Furthermore, we demonstrate that the effective electric field induced by the sapphire substrate could adjust the Schottky barrier from a p-type contact (WSe/Gr/sapphire) to an n-type contact (Gr/WSe/sapphire). Consequently, it is more beneficial for the photo-thermionic electrons to transfer from graphene to WSe over the Schottky barrier in Gr/WSe/sapphire. These results can provide new insights into the CT process in graphene-transition metal dichalcogenide (TMDC) vdW interfaces, which are critical to potential optoelectronic applications of graphene-TMDC heterostructures.

Download full-text PDF

Source
http://dx.doi.org/10.1039/d1nr07698aDOI Listing

Publication Analysis

Top Keywords

optoelectronic applications
8
sapphire substrate
8
schottky barrier
8
tunable ultrafast
4
ultrafast electron
4
transfer
4
electron transfer
4
transfer wse-graphene
4
heterostructures
4
wse-graphene heterostructures
4

Similar Publications

Optoelectronic polymer memristors with dynamic control for power-efficient in-sensor edge computing.

Light Sci Appl

September 2025

State Key Laboratory of Flexible Electronics, Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications (NUPT), Nanjing, 210023, China.

As the demand for edge platforms in artificial intelligence increases, including mobile devices and security applications, the surge in data influx into edge devices often triggers interference and suboptimal decision-making. There is a pressing need for solutions emphasizing low power consumption and cost-effectiveness. In-sensor computing systems employing memristors face challenges in optimizing energy efficiency and streamlining manufacturing due to the necessity for multiple physical processing components.

View Article and Find Full Text PDF

Ether-based electrolytes are widely acknowledged for their potential to form stable solid electrolyte interfaces (SEIs) for stable anode performance. However, conventional ether-based electrolytes have shown a tendency for cation-solvent co-intercalation phenomena on graphite electrodes, resulting in lower capacity and higher voltage platforms compared to those of neat cation insertion in ester-based electrolytes. In response, we propose the development of weakly solvating ether solvents to weaken the interaction between cations and solvents, thereby suppressing co-intercalation behavior.

View Article and Find Full Text PDF

In situ rapid gelation and osmotic dehydration-assisted preparation of graphene aerogel and its application in piezoresistive sensors.

J Colloid Interface Sci

September 2025

State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.. Electronic address:

This study presents a straightforward and rapid method for preparing graphene aerogel by integrating a sodium alginate (SA)-metal ion crosslinking system, a bubble template, and an osmotic dehydration process. Graphene oxide (GO) nanosheets were dispersed into the solution crosslinked by SA and metal ions, leading to rapid gelation of GO under ambient conditions. To minimize structural damage to the porous network caused by water molecules during the drying process, an osmotic dehydration technique was employed as an auxiliary drying method.

View Article and Find Full Text PDF

Ultra-sensitivity real-time water pollution detection based on non-Hermitian topolectrical circuit.

J Hazard Mater

September 2025

Key Laboratory of advanced optoelectronic quantum architecture and measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing 100081, China. Electronic address:

Ultra-sensitivity water pollution detection is the key to ensuring clean and safe management of water resources. However, most existing high-sensitivity water pollution detection systems rely on expensive and bulky laboratory equipment, which makes the systems non-portable. Meanwhile, most reported portable detection systems cannot meet the requirements for sensitivity and robustness in complex environments.

View Article and Find Full Text PDF

Perovskite materials have revolutionized optoelectronics by virtue of their tunable bandgaps, exceptional optoelectronic properties, and structural flexibility. Notably, the state-of-the-art performance of perovskite solar cells has reached 27%, making perovskite materials a promising candidate for next-generation photovoltaic technology. Although numerous reviews regarding perovskite materials have been published, the existing reviews generally focus on individual material systems (e.

View Article and Find Full Text PDF