Junpeng Zeng, Daowei He, Jingsi Qiao, Yating Li, Li Sun, Weisheng Li, Jiacheng Xie, Si Gao, Lijia Pan, Peng Wang, Yong Xu, Yun Li, Hao Qiu, Yi Shi, Jian-Bin Xu, Wei Ji & Xinran Wang
Abstract:
Organic field-effect transistors (OFETs) are of interest in unconventional form of electronics. However, high-performance OFETs are currently contact-limited, which represent a major challenge toward operation in the gigahertz regime. Here, we realize ultralow total contact resistance (Rc) down to 14.0 Ω ∙ cm in C10-DNTT OFETs by using transferred platinum (Pt) as contact. We observe evidence of Pt-catalyzed dehydrogenation of side alkyl chains which effectively reduces the metal-semiconductor van der Waals gap and promotes orbital hybridization. We report the ultrahigh performance OFETs, including hole mobility of 18 cm2 V−1 s−1, saturation current of 28.8 μA/μm, subthreshold swing of 60 mV/dec, and intrinsic cutoff frequency of 0.36 GHz. We further develop resist-free transfer and patterning strategies to fabricate large-area OFET arrays, showing 100% yield and excellent variability in the transistor metrics. As alkyl chains widely exist in conjugated molecules and polymers, our strategy can potentially enhance the performance of a broad range of organic optoelectronic devices.
The aim of atom electronics, i.e. the final scale of electronics, is to make use of specific individual atoms as active electronic components. Here, we review recent researches on atom electronics in single-molecule transistors (SMTs) through single-atom access and manipulation. We begin by describing the basic concepts and characteristics of atom electronics in SMTs, before discussing some of the most recent examples, including atomic transistors and atomic storage. In our concluding remarks, we discuss some perspectives on fabrication, integration, and other potential atomic devices in which high precision access to, and manipulation of single atoms could be of great significance. This will affect integrated circuits, quantum computing, and other devices that will drive the electronics of the future.
Abstract: High-capacity electrochemical energy storage systems are more urgently needed than ever before with the rapid development of electric vehicles and the smart grid. The most efficient way to increase capacity is to develop electrode materials with low molecular weights. The low-cost metal halides are theoretically ideal cathode materials due to their advantages of high capacity and redox potential. However, their cubic structure and large energy barrier for deionization impede their rechargeability. Here, the reversibility of potassium halides, lithium halides, sodium halides, and zinc halides is achieved through decreasing their dimensionality by the strong π–cation interactions between metal cations and reduced graphene oxide (rGO). Especially, the energy densities of KI-, KBr-, and KCl-based materials are 722.2, 635.0, and 739.4 Wh kg−1, respectively, which are higher than those of other cathode materials for potassium-ion batteries. In addition, the full-cell with 2D KI/rGO as cathode and graphite as anode demonstrates a lifespan of over 150 cycles with a considerable capacity retention of 57.5%. The metal halides-based electrode materials possess promising application prospects and are worthy of more in-depth researches.
Grain boundaries in two-dimensional (2D) semiconductors generally induce distorted band alignment and interfacial charge, which impair their electronic properties for device applications. Here, we report the improvement of band alignment at the grain boundaries of PtSe2, a 2D semiconductor, with selective adsorption of a presentative organic acceptor, tetracyanoquinodimethane (TCNQ). TCNQ molecules show selective adsorption at the PtSe2 grain boundary with strong interfacial charge. The adsorption of TCNQ distinctly improves the band alignment at the PtSe2 grain boundaries. With the charge transfer between the grain boundary and TCNQ, the local charge is inhibited, and the band bending at the grain boundary is suppressed, as revealed by the scanning tunneling microscopy and spectroscopy (STM/S) results. Our finding provides an effective method for the advancement of the band alignment at the grain boundary by functional molecules, improving the electronic properties of 2D semiconductors for their future applications.
主要工作成果 Selected Publications (代表性年度论文) Ferroelectricity in untwisted heterobilayers of transition metal dichalcogenides Lukas ROGÉE#, Lvjin WANG#,…, Manish CHHOWALLA*, Wei JI*, and Shu Ping LAU* Science 376(6596) pp.973-978 (2022)
Van der Waals epitaxial growth of air-stable CrSe2 nanosheets with thickness-tunable magnetic order Bo Li#, Zhong Wang#, Cong Wang#, Peng Chen#, Xidong Duan*, Wei Ji*, Xiangfeng Duan*, et al. Nature Materials 20, 818-825 (2021)
Universal mechanical exfoliation of large-area 2D crystals Yuan Huang, Yu-Hao Pan, Rong Yang … Peter Sutter*, Wei Ji*, Xing-Jiang Zhou* and Hong-Jun Gao* Nature Communications 11, 2453 (2020)
Stacking tunable interlayer magnetism in bilayer CrI3 Peiheng Jiang, Cong Wang … Zhicheng Zhong* and Wei Ji* Phys. Rev. B 99, 144401 (2019) arXiv:1806.09274 PRB Editors’ Suggestion
Few-layer Tellurium: one-dimensional-like layered elementary semiconductor with striking physical properties Jingsi Qiao, Yuhao Pan, Feng Yang, Cong Wang, Yang Chai and Wei Ji* Sci. Bull. 63(3), 159-168 (2018)
