1
|
Zhou M, Zhu W, Bao S, Zhou J, Yu Y, Zhang Q, Ren C, Li Z, Deng Y. Localized Surface Doping Induced Ultralow Contact Resistance between Metal and (Bi,Sb) 2Te 3 Thermoelectric Films. ACS APPLIED MATERIALS & INTERFACES 2024; 16:35815-35824. [PMID: 38935440 DOI: 10.1021/acsami.4c06713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/29/2024]
Abstract
Micro thermoelectric devices are expected to further improve the cooling density for the temperature control of electronic devices; nevertheless, the high contact resistivity between metals and semiconductors critically limits their applications, especially in chip cooling with extremely high heat flux. Herein, based on the calculated results, a low specific contact resistivity of ∼10-7 Ω cm2 at the interface is required to guarantee a desirable cooling power density of micro devices. Thus, we developed a generally applicable interfacial modulation strategy via localized surface doping of thermoelectric films, and the feasibility of such a doping approach for both n/p-type (Bi,Sb)2Te3 films was demonstrated, which can effectively increase the surface-majority carrier concentration explained by the charge transfer mechanism. With a proper doping level, ultralow specific contact resistivities at the interfaces are obtained for n-type (6.71 × 10-8 Ω cm2) and p-type (3.70 × 10-7 Ω cm2) (Bi,Sb)2Te3 layers, respectively, which is mainly attributed to the carrier tunneling enhancement with a narrowed interfacial contact barrier width. This work provides an effective scheme to further reduce the internal resistance of micro thermoelectric coolers, which can also be extended as a kind of universal interfacial modification technique for micro semiconductor devices.
Collapse
Affiliation(s)
- Man Zhou
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Wei Zhu
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
- Key Laboratory of Intelligent Sensing Materials and Chip Integration Technology of Zhejiang Province (2021E10022), Hangzhou Innovation Institute of Beihang University, Hangzhou 310052, China
| | - Shucheng Bao
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Jie Zhou
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Yuedong Yu
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Qingqing Zhang
- Key Laboratory of Intelligent Sensing Materials and Chip Integration Technology of Zhejiang Province (2021E10022), Hangzhou Innovation Institute of Beihang University, Hangzhou 310052, China
| | - Chaojie Ren
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Zhi Li
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
| | - Yuan Deng
- School of Materials Science and Engineering, Beihang University, Beijing 100191, China
- Key Laboratory of Intelligent Sensing Materials and Chip Integration Technology of Zhejiang Province (2021E10022), Hangzhou Innovation Institute of Beihang University, Hangzhou 310052, China
| |
Collapse
|
2
|
Zou F, Cong Y, Song W, Liu H, Li Y, Zhu Y, Zhao Y, Pan Y, Li Q. Interfacial Properties of Anisotropic Monolayer SiAs Transistors. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:238. [PMID: 38334509 PMCID: PMC10856446 DOI: 10.3390/nano14030238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 02/10/2024]
Abstract
The newly prepared monolayer (ML) SiAs is expected to be a candidate channel material for next-generation nano-electronic devices in virtue of its proper bandgap, high carrier mobility, and anisotropic properties. The interfacial properties in ML SiAs field-effect transistors are comprehensively studied with electrodes (graphene, V2CO2, Au, Ag, and Cu) by using ab initio electronic structure calculations and quantum transport simulation. It is found that ML SiAs forms a weak van der Waals interaction with graphene and V2CO2, while it forms a strong interaction with bulk metals (Au, Ag, and Cu). Although ML SiAs has strong anisotropy, it is not reflected in the contact property. Based on the quantum transport simulation, ML SiAs forms n-type lateral Schottky contact with Au, Ag, and Cu electrodes with the Schottky barrier height (SBH) of 0.28 (0.27), 0.40 (0.47), and 0.45 (0.33) eV along the a (b) direction, respectively, while it forms p-type lateral Schottky contact with a graphene electrode with a SBH of 0.34 (0.28) eV. Fortunately, ML SiAs forms an ideal Ohmic contact with the V2CO2 electrode. This study not only gives a deep understanding of the interfacial properties of ML SiAs with electrodes but also provides a guide for the design of ML SiAs devices.
Collapse
Affiliation(s)
- Feihu Zou
- College of Physics, Qingdao University, Qingdao 266071, China
| | - Yao Cong
- State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Weiqi Song
- College of Physics, Qingdao University, Qingdao 266071, China
| | - Haosong Liu
- State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Yanan Li
- State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Yifan Zhu
- State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Yue Zhao
- College of Physics, Qingdao University, Qingdao 266071, China
| | - Yuanyuan Pan
- College of Physics, Qingdao University, Qingdao 266071, China
| | - Qiang Li
- College of Physics, Qingdao University, Qingdao 266071, China
| |
Collapse
|
3
|
Wang X, Hu Y, Kim SY, Addou R, Cho K, Wallace RM. Origins of Fermi Level Pinning for Ni and Ag Metal Contacts on Tungsten Dichalcogenides. ACS NANO 2023; 17:20353-20365. [PMID: 37788682 DOI: 10.1021/acsnano.3c06494] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Tungsten transition metal dichalcogenides (W-TMDs) are intriguing due to their properties and potential for application in next-generation electronic devices. However, strong Fermi level (EF) pinning manifests at the metal/W-TMD interfaces, which could tremendously restrain the carrier injection into the channel. In this work, we illustrate the origins of EF pinning for Ni and Ag contacts on W-TMDs by considering interface chemistry, band alignment, impurities, and imperfections of W-TMDs, contact metal adsorption mechanism, and the resultant electronic structure. We conclude that the origins of EF pinning at a covalent contact metal/W-TMD interface, such as Ni/W-TMDs, can be attributed to defects, impurities, and interface reaction products. In contrast, for a van der Waals contact metal/TMD system such as Ag/W-TMDs, the primary factor responsible for EF pinning is the electronic modification of the TMDs resulting from the defects and impurities with the minor impact of metal-induced gap states. The potential strategies for carefully engineering the metal deposition approach are also discussed. This work unveils the origins of EF pinning at metal/TMD interfaces experimentally and theoretically and provides guidance on further enhancing and improving the device performance.
Collapse
Affiliation(s)
- Xinglu Wang
- Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Yaoqiao Hu
- Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Seong Yeoul Kim
- Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Rafik Addou
- Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Kyeongjae Cho
- Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Robert M Wallace
- Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
| |
Collapse
|
4
|
Zhang D. DFT Simulation of a Gold Electrode Vapor-Deposition Growth Process and the Effect of Defects on the Electrode Work Function. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:5649-5654. [PMID: 37052629 DOI: 10.1021/acs.langmuir.2c02710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
While two-dimensional (2D) semiconductors are explored as field-effect transistor (FET) channel materials for decreasing the short channel effects, electrical contact with 2D semiconductors is a major issue. Many efforts have been made toward this issue. However, the discrepancy in the contact type and the Schottky barrier height from the same contact is present in experiments. This discrepancy supposedly should be associated with the vapor-deposition electrode structures, on which little attention had been focused. Here, the crystal growth of the gold vapor-deposition electrode is simulated by adding gold atoms to the gold substrate one by one in the framework of density functional theory, and for every step, the spontaneously searching adsorption site method is used to find thermodynamically stable adsorption sites and the climbing nudged elastic band method is used to find kinetically stable ones. Simulation shows that the Au(111) face grows according to the ABC sequence packing, and possible defects are interstitial, vacancy, and the partly filled nascent layer (PFNL). These defects have an unequal effect on the electrode work function. The PFNL may be a non-negligible factor responsible for the discrepancy.
Collapse
Affiliation(s)
- Daoyu Zhang
- School of Physics, Southeast University, Nanjing 211189, China
| |
Collapse
|
5
|
Xu H, Hong Q, Zhang ZY, Cai X, Fan Y, Liu Z, Huang W, Yan N, Qu Z, Zhang L. SO 2-Driven In Situ Formation of Superstable Hg 3Se 2Cl 2 for Effective Flue Gas Mercury Removal. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:5424-5432. [PMID: 36939455 DOI: 10.1021/acs.est.2c09640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Flue gas mercury removal is mandatory for decreasing global mercury background concentration and ecosystem protection, but it severely suffers from the instability of traditional demercury products (e.g., HgCl2, HgO, HgS, and HgSe). Herein, we demonstrate a superstable Hg3Se2Cl2 compound, which offers a promising next-generation flue gas mercury removal strategy. Theoretical calculations revealed a superstable Hg bonding structure in Hg3Se2Cl2, with the highest mercury dissociation energy (4.71 eV) among all known mercury compounds. Experiments demonstrate its unprecedentedly high thermal stability (>400 °C) and strong acid resistance (5% H2SO4). The Hg3Se2Cl2 compound could be produced via the reduction of SeO32- to nascent active Se0 by the flue gas component SO2 and the subsequent combination of Se0 with Hg0 and Cl- ions or HgCl2. During a laboratory-simulated experiment, this Hg3Se2Cl2-based strategy achieves >96% removal efficiencies of both Hg0 and HgCl2 enabling nearly zero Hg0 re-emission. As expected, real mercury removal efficiency under Se-rich industrial flue gas conditions is much more efficient than Se-poor counterparts, confirming the feasibility of this Hg3Se2Cl2-based strategy for practical applications. This study sheds light on the importance of stable demercury products in flue gas mercury treatment and also provides a highly efficient and safe flue gas demercury strategy.
Collapse
Affiliation(s)
- Haomiao Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qinyuan Hong
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhao-Yang Zhang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200092, China
| | - Xiangling Cai
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yurui Fan
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhisong Liu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, China
| | - Wenjun Huang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Naiqiang Yan
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Zan Qu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lizhi Zhang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| |
Collapse
|
6
|
Hu Y, Hu X, Wang Y, Lu C, Krasheninnikov AV, Chen Z, Sun L. Suppressed Fermi Level Pinning and Wide-Range Tunable Schottky Barrier in CrX 3 (X = I, Br)/2D Metal Contacts. J Phys Chem Lett 2023; 14:2807-2815. [PMID: 36912604 DOI: 10.1021/acs.jpclett.3c00354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
CrX3 (X = I, Br) monolayers exhibit outstanding performance in spintronic devices. However, the Schottky barrier at the CrX3/electrode interface severely impedes the charge injection efficiency. Herein, we propose two-dimensional (2D) metals as electrodes to form van der Waals (vdW) contact with CrX3 monolayers and systematically explore the contact properties of CrX3/metal by density functional theory (DFT) calculations. The results demonstrate that the strongly suppressed Fermi level pinning (FLP) effect and the wide-range tunable Schottky barrier can be achieved in CrX3/metal contacts. Specifically, the n-type and the p-type Schottky contacts can be realized in CrX3/metal contacts by choosing 2D metal electrodes with different work functions. Importantly, the pinning factors for CrX3/metal contacts are exceptionally larger than other commonly studied 2D semiconductors, indicating the strongly suppressed FLP in CrX3/metal contacts, which leads to the wide-range tunable Schottky barrier. Our findings provide guidance to the choice of electrodes and promote the development of CrX3-based spin devices.
Collapse
Affiliation(s)
- Yanmei Hu
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Xiaohui Hu
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 211816, China
| | - Yifeng Wang
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 211816, China
| | - Chunhua Lu
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 211816, China
| | - Arkady V Krasheninnikov
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
- Department of Applied Physics, Aalto University School of Science, P.O. Box 11100, 00076 Aalto, Finland
| | - Zhongfang Chen
- Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, San Juan, Puerto Rico 00931, United States
| | - Litao Sun
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System, Southeast University, Nanjing 210096, China
| |
Collapse
|