Understanding the electron transport through transition-metal dichalcogenide (TMDC)-based semiconductor/metal junctions is vital for the realization of future TMDC-based (opto-)electronic devices. Despite the bonding in TMDCs being largely constrained within the layers, strong Fermi-level pinning (FLP) was observed in TMDC-based devices, reducing the tunability of the Schottky barrier height. We present evidence that metal-induced gap states (MIGS) are the origin for the large FLP similar to conventional semiconductors. A variety of TMDCs (MoSe, WSe, WS, and MoTe) were investigated using high-spatial-resolution surface characterization techniques, permitting us to distinguish between defected and pristine regions. The Schottky barrier heights on the pristine regions can be explained by MIGS, inducing partial FLP. The FLP strength is further enhanced by disorder-induced gap states induced by transition-metal vacancies or substitutionals at the defected regions. Our findings emphasize the importance of defects on the electron transport properties in TMDC-based devices and confirm the origin of FLP in TMDC-based metal/semiconductor junctions.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6410613 | PMC |
http://dx.doi.org/10.1021/acs.jpcc.8b10971 | DOI Listing |
Nano Lett
December 2024
SKKU Advanced Institute of Nano Technology and Department of Nano Science and Technology, Sungkyunkwan University, Suwon 16419, Republic of Korea.
In two-dimensional (2D) nanomaterial electronics, vertical field-effect transistors (VFETs), where charges flow perpendicular to the channel materials, hold promise due to the ease of forming ultrashort channel lengths by utilizing the thinness of 2D materials. However, the poor performance of p-type VFET arises from the lack of a gate-field-penetrating electrode with suitable work functions, which is essential for VFET operation. This motivated us to replace graphene (work function of ∼4.
View Article and Find Full Text PDFACS Nano
December 2024
Department of Physics, Yonsei University, Seoul 03722, Republic of Korea.
To achieve the commercialization of two-dimensional (2D) semiconductors, the identification of an appropriate combination of 2D semiconductors and three-dimensional (3D) metals is crucial. Furthermore, understanding the van der Waals (vdW) interactions between these materials in thin-film semiconductor processes is essential. Optimizing these interactions requires precise control over the properties of the vdW interface through specific pre- or post-treatment methods.
View Article and Find Full Text PDFMater Horiz
December 2024
School of Electronic and Computer Engineering, Peking University, Shenzhen 518055, China.
The decoupling of electronic states between metals and semiconductors through controlled construction of artificial van der Waals (vdW) heterojunctions enables tailored Schottky barriers. However, the interfacial chemistry, especially involving solid-liquid interfaces, remains unexplored. Here, first principles calculations reveal unexpected strong Fermi-level pinning in various metal/MoS vdW heterojunctions with intercalated ice-like water bilayers.
View Article and Find Full Text PDFJ Chem Phys
December 2024
Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070, China.
The significant open-circuit voltage (VOC) deficit poses a major obstacle to enhancing the efficiency of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells. Interface passivation emerges as a potent strategy to regulate carrier transport and boost performance. Here, we innovatively introduced rare-earth lanthanum (La) to passivate the absorber interface by directly treating the absorption layer surface with an aqueous La3+ ion solution.
View Article and Find Full Text PDFJ Phys Chem Lett
December 2024
Center of Excellence in Materials and Advanced Technologies (CeMAT), Faculty of Engineering and Technology, SRM institute of Science and Technology, Kattankulathur 603 203, India.
We fabricated radially transformed growth of MoS to MoS-MoO by the two-zone chemical vapor transport (CVT) technique. The idea to apply heat, i.e.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!