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Yoon H, Lee S, Seo J, Sohn I, Jun S, Hong S, Im S, Nam Y, Kim HJ, Lee Y, Chung SM, Kim H. Investigation on Contact Properties of 2D van der Waals Semimetallic 1T-TiS 2/MoS 2 Heterojunctions. ACS APPLIED MATERIALS & INTERFACES 2024; 16:12095-12105. [PMID: 38384197 DOI: 10.1021/acsami.3c18982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Two-dimensional transition metal dichalcogenides (2D TMDCs) are considered promising alternatives to Si as channel materials because of the possibility of retaining their superior electronic transport properties even at atomic body thicknesses. However, the realization of high-performance 2D TMDC field-effect transistors remains a challenge owing to Fermi-level pinning (FLP) caused by gap states and the inherent high Schottky barrier height (SBH) within the metal contact and channel layer. This study demonstrates that high-quality van der Waals (vdW) heterojunction-based contacts can be formed by depositing semimetallic TiS2 onto monolayer (ML) MoS2. After confirming the successful formation of a TiS2/ML MoS2 heterojunction, the contact properties of vdW semimetal TiS2 were thoroughly investigated. With clean interfaces of the TiS2/ML MoS2 heterojunctions, atomic-layer-deposited TiS2 can induce gap-state saturation and suppress FLP. Consequently, compared with conventional evaporated metal electrodes, the TiS2/ML MoS2 heterojunctions exhibit a lower SBH of 8.54 meV and better contact properties. This, in turn, substantially improves the overall performance of the device, including its on-current, subthreshold swing, and threshold voltage. Furthermore, we believe that our proposed strategy for vdW-based contact formation will contribute to the development of 2D materials used in next-generation electronics.
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Affiliation(s)
- Hwi Yoon
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Sangyoon Lee
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Jeongwoo Seo
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Inkyu Sohn
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Sukhwan Jun
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Sungjae Hong
- van der Waals Materials Research Center, Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
| | - Seongil Im
- van der Waals Materials Research Center, Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
| | - Yunyong Nam
- Samsung Display Co., Ltd, Yongin-si, Gyeonggi-do 17113, Republic of Korea
| | - Hyung-Jun Kim
- Samsung Display Co., Ltd, Yongin-si, Gyeonggi-do 17113, Republic of Korea
| | - Yujin Lee
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Seung-Min Chung
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Hyungjun Kim
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
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2
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Yadav AK, Ma W, Abi Younes P, Ciatto G, Gauthier N, Skopin E, Quadrelli EA, Schneider N, Renevier H. Quantitative in situ synchrotron X-ray analysis of the ALD/MLD growth of transition metal dichalcogenide TiS 2 ultrathin films. NANOSCALE 2024; 16:1853-1864. [PMID: 38167682 DOI: 10.1039/d3nr04222g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
We present the results of a full quantitative analysis of X-ray absorption spectroscopy (XAS) performed in situ during the growth of ultrathin titanium disulfide (TiS2) films via an innovative two-step process, i.e. atomic layer deposition/molecular layer deposition (ALD/MLD) followed by annealing. This growth strategy aims at separating the growth process from the crystallization process by first creating an amorphous Ti-thiolate that is converted later to crystalline TiS2via thermal annealing. The simultaneous analysis of Ti and S K-edge XAS spectra, exploiting the insights from density functional theory calculations, allows us to shed light on the chemical and structural mechanisms underlying the main steps of growth. The nature of the bonding at the base of the interface creation with the SiO2 substrate is disclosed in this study. Evidence of a progressive incorporation of S in the amorphous Ti-thiolate is given. Finally, it is shown that the annealing step plays a critical role since the transformation of the Ti-thiolate into nanocrystalline TiS2 and the loss of S are simultaneously induced, validating the two-step synthesis approach, which entails distinct growth and crystallization steps. These observations contribute to a deeper understanding of the bonding mechanism at the interface and provide insights for future research in this field and the generation of ultra-thin layered materials.
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Affiliation(s)
- Ashok-Kumar Yadav
- Synchrotron SOLEIL, Beamline SIRIUS, Saint-Aubin, F-91192, Gif sur Yvette, France.
| | - Weiliang Ma
- IPVF (UMR 9006), Institut Photovoltaïque d'Ile-de-France, F-91120 Palaiseau, France
| | - Petros Abi Younes
- Univ. Grenoble Alpes, CNRS, Grenoble-INP, LMGP, F-38000 Grenoble, France
- Univ. Grenoble Alpes, CEA, LETI, F-38000 Grenoble, France
| | - Gianluca Ciatto
- Synchrotron SOLEIL, Beamline SIRIUS, Saint-Aubin, F-91192, Gif sur Yvette, France.
| | | | - Evgeniy Skopin
- Univ. Grenoble Alpes, CNRS, Grenoble-INP, LMGP, F-38000 Grenoble, France
| | | | | | - Hubert Renevier
- Univ. Grenoble Alpes, CNRS, Grenoble-INP, LMGP, F-38000 Grenoble, France
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3
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Brune V, Hegemann C, Wilhelm M, Ates N, Mathur S. Molecular Precursors to Group IV Dichalcogenides MS2 (M = Ti, Zr, Hf). Z Anorg Allg Chem 2022. [DOI: 10.1002/zaac.202200049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Veronika Brune
- University of Cologne: Universitat zu Koln Chemie Greinstraße 6 50939 Cologne GERMANY
| | | | | | | | - Sanjay Mathur
- Institut für Anorganische Chemie Universität zu Köln Anorganische Chemie Greinstr. 6 50939 Köln GERMANY
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4
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Tanwar S, Arya A, Gaur A, Sharma AL. Transition metal dichalcogenide (TMDs) electrodes for supercapacitors: a comprehensive review. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:303002. [PMID: 33892487 DOI: 10.1088/1361-648x/abfb3c] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 04/23/2021] [Indexed: 06/12/2023]
Abstract
As globally, the main focus of the researchers is to develop novel electrode materials that exhibit high energy and power density for efficient performance energy storage devices. This review covers the up-to-date progress achieved in transition metal dichalcogenides (TMDs) (e.g. MoS2, WS2, MoSe2,and WSe2) as electrode material for supercapacitors (SCs). The TMDs have remarkable properties like large surface area, high electrical conductivity with variable oxidation states. These properties enable the TMDs as the most promising candidates to store electrical energy via hybrid charge storage mechanisms. Consequently, this review article provides a detailed study of TMDs structure, properties, and evolution. The characteristics technique and electrochemical performances of all the efficient TMDs are highlighted meticulously. In brief, the present review article shines a light on the structural and electrochemical properties of TMD electrodes. Furthermore, the latest fabricated TMDs based symmetric/asymmetric SCs have also been reported.
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Affiliation(s)
- Shweta Tanwar
- Department of Physics, Central University of Punjab, Bathinda-151401, Punjab, India
| | - Anil Arya
- Department of Physics, Central University of Punjab, Bathinda-151401, Punjab, India
| | - Anurag Gaur
- Department of Physics, National Institute of Technology, Kurukshetra-136119, Haryana, India
| | - A L Sharma
- Department of Physics, Central University of Punjab, Bathinda-151401, Punjab, India
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5
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Basuvalingam SB, Zhang Y, Bloodgood MA, Godiksen RH, Curto AG, Hofmann JP, Verheijen MA, Kessels WMM, Bol AA. Low-Temperature Phase-Controlled Synthesis of Titanium Di- and Tri-sulfide by Atomic Layer Deposition. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2019; 31:9354-9362. [PMID: 31806923 PMCID: PMC6883357 DOI: 10.1021/acs.chemmater.9b02895] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 10/25/2019] [Indexed: 06/01/2023]
Abstract
Phase-controlled synthesis of two-dimensional (2D) transition-metal chalcogenides (TMCs) at low temperatures with a precise thickness control has to date been rarely reported. Here, we report on a process for the phase-controlled synthesis of TiS2 (metallic) and TiS3 (semiconducting) nanolayers by atomic layer deposition (ALD) with precise thickness control. The phase control has been obtained by carefully tuning the deposition temperature and coreactant composition during ALD. In all cases, characteristic self-limiting ALD growth behavior with a growth per cycle (GPC) of ∼0.16 nm per cycle was observed. TiS2 was prepared at 100 °C using H2S gas as coreactant and was also observed using H2S plasma as a coreactant at growth temperatures between 150 and 200 °C. TiS3 was synthesized only at 100 °C using H2S plasma as the coreactant. The S2 species in the H2S plasma, as observed by optical emission spectroscopy, has been speculated to lead to the formation of the TiS3 phase at low temperatures. The control between the synthesis of TiS2 and TiS3 was elucidated by Raman spectroscopy, X-ray photoelectron spectroscopy, high-resolution electron microscopy, and Rutherford backscattering study. Electrical transport measurements showed the low resistive nature of ALD grown 2D-TiS2 (1T-phase). Postdeposition annealing of the TiS3 layers at 400 °C in a sulfur-rich atmosphere improved the crystallinity of the film and yielded photoluminescence at ∼0.9 eV, indicating the semiconducting (direct band gap) nature of TiS3. The current study opens up a new ALD-based synthesis route for controlled, scalable growth of transition-metal di- and tri-chalcogenides at low temperatures.
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Affiliation(s)
- Saravana Balaji Basuvalingam
- Department
of Applied Physics and Laboratory for Inorganic Materials and Catalysis,
Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | | | - Matthew A. Bloodgood
- Department
of Applied Physics and Laboratory for Inorganic Materials and Catalysis,
Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Rasmus H. Godiksen
- Department
of Applied Physics and Laboratory for Inorganic Materials and Catalysis,
Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Alberto G. Curto
- Department
of Applied Physics and Laboratory for Inorganic Materials and Catalysis,
Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Jan P. Hofmann
- Department
of Applied Physics and Laboratory for Inorganic Materials and Catalysis,
Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Marcel A. Verheijen
- Department
of Applied Physics and Laboratory for Inorganic Materials and Catalysis,
Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Eurofins
Materials Science, High
Tech Campus 11, 5656 AE Eindhoven, The Netherlands
| | - Wilhelmus M. M. Kessels
- Department
of Applied Physics and Laboratory for Inorganic Materials and Catalysis,
Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Ageeth A. Bol
- Department
of Applied Physics and Laboratory for Inorganic Materials and Catalysis,
Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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6
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Aljabour A, Coskun H, Zheng X, Kibria MG, Strobel M, Hild S, Kehrer M, Stifter D, Sargent EH, Stadler P. Active Sulfur Sites in Semimetallic Titanium Disulfide Enable CO2 Electroreduction. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02872] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
| | | | - Xueli Zheng
- Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King’s College Road, Toronto, Ontario M5S 3G4, Canada
| | - Md Golam Kibria
- Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King’s College Road, Toronto, Ontario M5S 3G4, Canada
| | | | | | | | | | - Edward H. Sargent
- Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King’s College Road, Toronto, Ontario M5S 3G4, Canada
| | - Philipp Stadler
- Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King’s College Road, Toronto, Ontario M5S 3G4, Canada
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7
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Zang X, Shen C, Kao E, Warren R, Zhang R, Teh KS, Zhong J, Wei M, Li B, Chu Y, Sanghadasa M, Schwartzberg A, Lin L. Titanium Disulfide Coated Carbon Nanotube Hybrid Electrodes Enable High Energy Density Symmetric Pseudocapacitors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:1704754. [PMID: 29227556 DOI: 10.1002/adma.201704754] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/20/2017] [Indexed: 05/26/2023]
Abstract
While electrochemical supercapacitors often show high power density and long operation lifetimes, they are plagued by limited energy density. Pseudocapacitive materials, in contrast, operate by fast surface redox reactions and are shown to enhance energy storage of supercapacitors. Furthermore, several reported systems exhibit high capacitance but restricted electrochemical voltage windows, usually no more than 1 V in aqueous electrolytes. Here, it is demonstrated that vertically aligned carbon nanotubes (VACNTs) with uniformly coated, pseudocapacitive titanium disulfide (TiS2 ) composite electrodes can extend the stable working range to over 3 V to achieve a high capacitance of 195 F g-1 in an Li-rich electrolyte. A symmetric cell demonstrates an energy density of 60.9 Wh kg-1 -the highest among symmetric pseudocapacitors using metal oxides, conducting polymers, 2D transition metal carbides (MXene), and other transition metal dichalcogenides. Nanostructures prepared by an atomic layer deposition/sulfurization process facilitate ion transportation and surface reactions to result in a high power density of 1250 W kg-1 with stable operation over 10 000 cycles. A flexible solid-state supercapacitor prepared by transferring the TiS2 -VACNT composite film onto Kapton tape is demonstrated to power a 2.2 V light emitting diode (LED) for 1 min.
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Affiliation(s)
- Xining Zang
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Caiwei Shen
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Emmeline Kao
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Roseanne Warren
- Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Ruopeng Zhang
- National Center for Electron Microscopy, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA
| | - Kwok Siong Teh
- School of Engineering, San Francisco State University, San Francisco, CA, 94132, USA
| | - Junwen Zhong
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Minsong Wei
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Buxuan Li
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Yao Chu
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | | | - Adam Schwartzberg
- Molecular Foundry, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA
| | - Liwei Lin
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
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8
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Kalanyan B, Beams R, Katz MB, Davydov AV, Maslar JE, Kanjolia RK. MoS 2 thin films from a (N t Bu) 2(NMe 2) 2Mo and 1-propanethiol atomic layer deposition process. JOURNAL OF VACUUM SCIENCE & TECHNOLOGY. A, VACUUM, SURFACES, AND FILMS : AN OFFICIAL JOURNAL OF THE AMERICAN VACUUM SOCIETY 2018; 37:10.1116/1.5059424. [PMID: 33281278 PMCID: PMC7713506 DOI: 10.1116/1.5059424] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 11/26/2018] [Indexed: 06/12/2023]
Abstract
Potential commercial applications for transition metal dichalcogenide (TMD) semiconductors such as MoS2 rely on unique material properties that are only accessible at monolayer to few-layer thickness regimes. Therefore, production methods that lend themselves to scalable and controllable formation of TMD films on surfaces are desirable for high volume manufacturing of devices based on these materials. We have developed a new thermal atomic layer deposition (ALD) process using bis(tert-butylimido)-bis(dimethylamido)molybdenum and 1-propanethiol to produce MoS2-containing amorphous films. We observe self-limiting reaction behavior with respect to both the Mo and S precursors at a substrate temperature of 350 °C. Film thickness scales linearly with precursor cycling, with growth per cycle values of ≈0.1 nm/cycle. As-deposited films are smooth and contain nitrogen and carbon impurities attributed to poor ligand elimination from the Mo source. Upon high-temperature annealing, a large portion of the impurities are removed, and we obtain few-layer crystalline 2H-MoS2 films.
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Affiliation(s)
- Berc Kalanyan
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
| | - Ryan Beams
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
| | - Michael B. Katz
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
| | - Albert V. Davydov
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
| | - James E. Maslar
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899
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9
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Ovanesyan RA, Hausmann DM, Agarwal S. Low-Temperature Conformal Atomic Layer Deposition of SiNx Films Using Si₂Cl₆ and NH₃ Plasma. ACS APPLIED MATERIALS & INTERFACES 2015; 7:10806-10813. [PMID: 25927250 DOI: 10.1021/acsami.5b01531] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A plasma-enhanced atomic layer deposition (ALD) process was developed for the growth of SiNx thin films using Si2Cl6 and NH3 plasma. At substrate temperatures ≤400 °C, we show that this ALD process leads to films with >95% conformality over high aspect ratio nanostructures with a growth per cycle of ∼1.2 Å. The film growth mechanism was studied using in situ attenuated total reflection Fourier transform infrared spectroscopy. Our data show that on the SiNx growth surface, Si2Cl6 reacts with surface -NH2 groups to form surface -NH species, which are incorporated into the growing film. In the subsequent half cycle, radicals generated in the NH3 plasma abstract surface Cl atoms, and restore an NHx (x = 1,2)-terminated surface. Surface Si-N-Si bonds are also primarily formed during the NH3 plasma half-cycle. The infrared data and Rutherford backscattering combined with hydrogen forward scattering shows that the films contain ∼23% H atoms primarily incorporated as -NH groups.
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Affiliation(s)
- Rafaiel A Ovanesyan
- †Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Dennis M Hausmann
- ‡Lam Research Corporation, 11155 SW Leveton Drive, Tualatin, Oregon 97062, United States
| | - Sumit Agarwal
- †Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
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10
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Dasgupta NP, Meng X, Elam JW, Martinson ABF. Atomic layer deposition of metal sulfide materials. Acc Chem Res 2015; 48:341-8. [PMID: 25581295 DOI: 10.1021/ar500360d] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
CONSPECTUS: The field of nanoscience is delivering increasingly intricate yet elegant geometric structures incorporating an ever-expanding palette of materials. Atomic layer deposition (ALD) is a powerful driver of this field, providing exceptionally conformal coatings spanning the periodic table and atomic-scale precision independent of substrate geometry. This versatility is intrinsic to ALD and results from sequential and self-limiting surface reactions. This characteristic facilitates digital synthesis, in which the film grows linearly with the number of reaction cycles. While the majority of ALD processes identified to date produce metal oxides, novel applications in areas such as energy storage, catalysis, and nanophotonics are motivating interest in sulfide materials. Recent progress in ALD of sulfides has expanded the diversity of accessible materials as well as a more complete understanding of the unique chalcogenide surface chemistry. ALD of sulfide materials typically uses metalorganic precursors and hydrogen sulfide (H2S). As in oxide ALD, the precursor chemistry is critical to controlling both the film growth and properties including roughness, crystallinity, and impurity levels. By modification of the precursor sequence, multicomponent sulfides have been deposited, although challenges remain because of the higher propensity for cation exchange reactions, greater diffusion rates, and unintentional annealing of this more labile class of materials. A deeper understanding of these surface chemical reactions has been achieved through a combination of in situ studies and quantum-chemical calculations. As this understanding matures, so does our ability to deterministically tailor film properties to new applications and more sophisticated devices. This Account highlights the attributes of ALD chemistry that are unique to metal sulfides and surveys recent applications of these materials in photovoltaics, energy storage, and photonics. Within each application space, the benefits and challenges of novel ALD processes are emphasized and common trends are summarized. We conclude with a perspective on potential future directions for metal chalcogenide ALD as well as untapped opportunities. Finally, we consider challenges that must be addressed prior to implementing ALD metal sulfides into future device architectures.
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Affiliation(s)
- Neil P. Dasgupta
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 41809, United States
| | - Xiangbo Meng
- Energy Systems Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Jeffrey W. Elam
- Energy Systems Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Alex B. F. Martinson
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
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