1
|
Kang M, Jeong HB, Shim Y, Chai HJ, Kim YS, Choi M, Ham A, Park C, Jo MK, Kim TS, Park H, Lee J, Noh G, Kwak JY, Eom T, Lee CW, Choi SY, Yuk JM, Song S, Jeong HY, Kang K. Layer-Controlled Growth of Single-Crystalline 2D Bi 2O 2Se Film Driven by Interfacial Reconstruction. ACS Nano 2024; 18:819-828. [PMID: 38153349 DOI: 10.1021/acsnano.3c09369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
As semiconductor scaling continues to reach sub-nanometer levels, two-dimensional (2D) semiconductors are emerging as a promising candidate for the post-silicon material. Among these alternatives, Bi2O2Se has risen as an exceptionally promising 2D semiconductor thanks to its excellent electrical properties, attributed to its appropriate bandgap and small effective mass. However, unlike other 2D materials, growth of large-scale Bi2O2Se films with precise layer control is still challenging due to its large surface energy caused by relatively strong interlayer electrostatic interactions. Here, we present the successful growth of a wafer-scale (∼3 cm) Bi2O2Se film with precise thickness control down to the monolayer level on TiO2-terminated SrTiO3 using metal-organic chemical vapor deposition (MOCVD). Scanning transmission electron microscopy (STEM) analysis confirmed the formation of a [BiTiO4]1- interfacial structure, and density functional theory (DFT) calculations revealed that the formation of [BiTiO4]1- significantly reduced the interfacial energy between Bi2O2Se and SrTiO3, thereby promoting 2D growth. Additionally, spectral responsivity measurements of two-terminal devices confirmed a bandgap increase of up to 1.9 eV in monolayer Bi2O2Se, which is consistent with our DFT calculations. Finally, we demonstrated high-performance Bi2O2Se field-effect transistor (FET) arrays, exhibiting an excellent average electron mobility of 56.29 cm2/(V·s). This process is anticipated to enable wafer-scale applications of 2D Bi2O2Se and facilitate exploration of intriguing physical phenomena in confined 2D systems.
Collapse
Affiliation(s)
- Minsoo Kang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Han Beom Jeong
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Yoonsu Shim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Hyun-Jun Chai
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Yong-Sung Kim
- Korea Research Institute of Standards & Science (KRISS), Daejeon 34113, Republic of Korea
| | - Minhyuk Choi
- Opernado Methodology and Measurement Team, Korea Research Institute of Standards & Science (KRISS), Daejeon 34113, Republic of Korea
| | - Ayoung Ham
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Cheolmin Park
- School of Electrical Engineering, Graphene/2D Materials Research Center, Center for Advanced Materials Discovery towards 3D Display, Korea Advanced Institute of Science and Technology (KAIST) 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Min-Kyung Jo
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- Opernado Methodology and Measurement Team, Korea Research Institute of Standards & Science (KRISS), Daejeon 34113, Republic of Korea
| | - Tae Soo Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Hyeonbin Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- Thin Film Materials Research Center, Korea Research Institute of Chemical Technology (KRICT) 141, Gajeong-ro, Daejeon 34114, Republic of Korea
| | - Jaehyun Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Gichang Noh
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- Center for Neuromorphic Engineering, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Joon Young Kwak
- Center for Neuromorphic Engineering, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Taeyong Eom
- Thin Film Materials Research Center, Korea Research Institute of Chemical Technology (KRICT) 141, Gajeong-ro, Daejeon 34114, Republic of Korea
| | - Chan-Woo Lee
- Computational Science & Engineering Laboratory, Korea Institute of Energy Research, Daejeon 34129, Republic of Korea
| | - Sung-Yool Choi
- School of Electrical Engineering, Graphene/2D Materials Research Center, Center for Advanced Materials Discovery towards 3D Display, Korea Advanced Institute of Science and Technology (KAIST) 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jong Min Yuk
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Seungwoo Song
- Opernado Methodology and Measurement Team, Korea Research Institute of Standards & Science (KRISS), Daejeon 34113, Republic of Korea
| | - Hu Young Jeong
- Graduate School of Semiconductor Materials and Devices Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Kibum Kang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- Graduate School of Semiconductor Technology, Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| |
Collapse
|
2
|
Torsi R, Munson KT, Pendurthi R, Marques E, Van Troeye B, Huberich L, Schuler B, Feidler M, Wang K, Pourtois G, Das S, Asbury JB, Lin YC, Robinson JA. Dilute Rhenium Doping and its Impact on Defects in MoS 2. ACS Nano 2023; 17:15629-15640. [PMID: 37534591 DOI: 10.1021/acsnano.3c02626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
Substitutionally doped 2D transition metal dichalcogenides are primed for next-generation device applications such as field effect transistors (FET), sensors, and optoelectronic circuits. In this work, we demonstrate substitutional rhenium (Re) doping of MoS2 monolayers with controllable concentrations down to 500 ppm by metal-organic chemical vapor deposition (MOCVD). Surprisingly, we discover that even trace amounts of Re lead to a reduction in sulfur site defect density by 5-10×. Ab initio models indicate the origin of the reduction is an increase in the free-energy of sulfur-vacancy formation at the MoS2 growth-front when Re is introduced. Defect photoluminescence (PL) commonly seen in undoped MOCVD MoS2 is suppressed by 6× at 0.05 atomic percent (at. %) Re and completely quenched with 1 at. % Re. Furthermore, we find that Re-MoS2 transistors exhibit a 2× increase in drain current and carrier mobility compared to undoped MoS2, indicating that sulfur vacancy reduction improves carrier transport in the Re-MoS2. This work provides important insights on how dopants affect 2D semiconductor growth dynamics, which can lead to improved crystal quality and device performance.
Collapse
Affiliation(s)
- Riccardo Torsi
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kyle T Munson
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Rahul Pendurthi
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Esteban Marques
- Imec, Leuven 3001, Belgium
- Department of Molecular Design and Synthesis, KU Leuven, Celestijnenlaan 200f - Postbox 2404, 3001 Leuven, Belgium
| | | | - Lysander Huberich
- nanotech@surfaces Laboratory, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - Bruno Schuler
- nanotech@surfaces Laboratory, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - Maxwell Feidler
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Ke Wang
- Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | | | - Saptarshi Das
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - John B Asbury
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Yu-Chuan Lin
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu City, 300093, Taiwan
| | - Joshua A Robinson
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| |
Collapse
|
3
|
Kwak HM, Lee JS, Park BI, Baik J, Kim J, Jeong WL, Kim KP, Mun SH, Kim H, Kim J, Lee DS. Stability of Graphene and Influence of AlN Surface Pits on GaN Remote Heteroepitaxy for Exfoliation. ACS Nano 2023. [PMID: 37279113 DOI: 10.1021/acsnano.3c02565] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Remote epitaxy is a promising technology that has recently attracted considerable attention, which enables the growth of thin films that copy the crystallographic characteristics of the substrate through two-dimensional material interlayers. The grown films can be exfoliated to form freestanding membranes, although it is often challenging to apply this technique if the substrate materials are prone to damage under harsh epitaxy conditions. For example, remote epitaxy of GaN thin films on graphene/GaN templates has not been achieved by a standard metal-organic chemical vapor deposition (MOCVD) method due to such damages. Here, we report GaN remote heteroepitaxy on graphene/AlN templates by MOCVD and investigate the influence of surface pits in AlN on the growth and exfoliation of GaN thin films. We first show the thermal stability of graphene before GaN growth, based on which two-step growth of GaN on graphene/AlN is developed. The GaN samples are successfully exfoliated after the first step of the growth at 750 °C, whereas the exfoliation failed after the second step at 1050 °C. In-depth analysis confirms that the pits in AlN templates lead to the degradation of graphene near the area and thus the alteration of growth modes and the failure of exfoliation. These results exemplify the importance of chemical and topographic properties of growth templates for successful remote epitaxy. It is one of the key factors for III-nitride-based remote epitaxy, and these results are expected to be of great help in realizing complete remote epitaxy using only MOCVD.
Collapse
Affiliation(s)
- Hoe-Min Kwak
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Je-Sung Lee
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Bo-In Park
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jaeyoung Baik
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Jeongwoon Kim
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Woo-Lim Jeong
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Kyung-Pil Kim
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Seung-Hyun Mun
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Hyunseok Kim
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jeehwan Kim
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Dong-Seon Lee
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| |
Collapse
|
4
|
Moon S, Chang SJ, Kim Y, Okello OFN, Kim J, Kim J, Jung HW, Ahn HK, Kim DS, Choi SY, Lee J, Lim JW, Kim JK. Van der Waals Heterostructure of Hexagonal Boron Nitride with an AlGaN/GaN Epitaxial Wafer for High-Performance Radio Frequency Applications. ACS Appl Mater Interfaces 2021; 13:59440-59449. [PMID: 34792331 DOI: 10.1021/acsami.1c15970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
While two-dimensional (2D) hexagonal boron nitride (h-BN) is emerging as an atomically thin and dangling bond-free insulating layer for next-generation electronics and optoelectronics, its practical implementation into miniaturized integrated circuits has been significantly limited due to difficulties in large-scale growth directly on epitaxial semiconductor wafers. Herein, the realization of a wafer-scale h-BN van der Waals heterostructure with a 2 in. AlGaN/GaN high-electron mobility transistor (HEMT) wafer using metal-organic chemical vapor deposition is presented. The combination of state-of-the-art microscopic and spectroscopic analyses and theoretical calculations reveals that the heterointerface between ∼2.5 nm-thick h-BN and AlGaN layers is atomically sharp and exhibits a very weak van der Waals interaction without formation of a ternary or quaternary alloy that can induce undesired degradation of device performance. The fabricated AlGaN/GaN HEMT with h-BN shows very promising performance including a cutoff frequency (fT) and maximum oscillation frequency (fMAX) as high as 28 and 88 GHz, respectively, enabled by an effective passivation of surface defects on the HEMT wafer to deliver accurate information with minimized power loss. These findings pave the way for practical implementation of 2D materials integrated with conventional microelectronic devices and the realization of future all-2D electronics.
Collapse
Affiliation(s)
- Seokho Moon
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 37673, Republic of Korea
| | - Sung-Jae Chang
- DMC Convergence Research Department, Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea
| | - Youngjae Kim
- Department of Emerging Materials Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno jungang-daero, Dalseong-gun, Daegu 42988, Republic of Korea
| | - Odongo Francis Ngome Okello
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 37673, Republic of Korea
| | - Jiye Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 37673, Republic of Korea
| | - Jaewon Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 37673, Republic of Korea
| | - Hyun-Wook Jung
- DMC Convergence Research Department, Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea
| | - Ho-Kyun Ahn
- DMC Convergence Research Department, Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea
| | - Dong-Seok Kim
- Korea Multi-Purpose Accelerator Complex, Korea Atomic Energy Research Institute (KAERI), 181 Mirae-ro, Geoncheon-eup, Gyeongju 38180, Republic of Korea
| | - Si-Young Choi
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 37673, Republic of Korea
| | - JaeDong Lee
- Department of Emerging Materials Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno jungang-daero, Dalseong-gun, Daegu 42988, Republic of Korea
| | - Jong-Won Lim
- DMC Convergence Research Department, Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea
| | - Jong Kyu Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 37673, Republic of Korea
| |
Collapse
|
5
|
Shi Y, Groven B, Serron J, Wu X, Nalin Mehta A, Minj A, Sergeant S, Han H, Asselberghs I, Lin D, Brems S, Huyghebaert C, Morin P, Radu I, Caymax M. Engineering Wafer-Scale Epitaxial Two-Dimensional Materials through Sapphire Template Screening for Advanced High-Performance Nanoelectronics. ACS Nano 2021; 15:9482-9494. [PMID: 34042437 DOI: 10.1021/acsnano.0c07761] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In view of its epitaxial seeding capability, c-plane single crystalline sapphire represents one of the most enticing, industry-compatible templates to realize manufacturable deposition of single crystalline two-dimensional transition metal dichalcogenides (MX2) for functional, ultrascaled, nanoelectronic devices beyond silicon. Despite sapphire being atomically flat, the surface topography, structure, and chemical termination vary between sapphire terraces during the fabrication process. To date, it remains poorly understood how these sapphire surface anomalies affect the local epitaxial registry and the intrinsic electrical properties of the deposited MX2 monolayer. Therefore, molybdenum disulfide (MoS2) is deposited by metal-organic chemical vapor deposition (MOCVD) in an industry-standard epitaxial reactor on two types of c-plane sapphire with distinctly different terrace and step dimensions. Complementary scanning probe microscopy techniques reveal an inhomogeneous conductivity profile in the first epitaxial MoS2 monolayer on both sapphire templates. MoS2 regions with poor conductivity correspond to sapphire terraces with uncontrolled topography and surface structure. By intentionally applying a substantial off-axis cut angle (1° in this work), the sapphire terrace width and step height-and thus also surface structure-become more uniform across the substrate and MoS2 conducts the current more homogeneously. Moreover, these effects propagate into the extrinsic MoS2 device performance: the field-effect transistor variability reduces both within and across wafers at higher median electron mobility. Carefully controlling the sapphire surface topography and structure proves an essential prerequisite to systematically study and control the MX2 growth behavior and capture the influence on its structural and electrical properties.
Collapse
Affiliation(s)
| | | | | | - Xiangyu Wu
- IMEC, Kapeldreef 75, 3001 Leuven, Belgium
- Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, 3001 Leuven, Belgium
| | - Ankit Nalin Mehta
- IMEC, Kapeldreef 75, 3001 Leuven, Belgium
- Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200d, 3001 Leuven, Belgium
| | - Albert Minj
- IMEC, Kapeldreef 75, 3001 Leuven, Belgium
- Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200d, 3001 Leuven, Belgium
| | | | - Han Han
- IMEC, Kapeldreef 75, 3001 Leuven, Belgium
| | | | - Dennis Lin
- IMEC, Kapeldreef 75, 3001 Leuven, Belgium
| | | | | | | | | | | |
Collapse
|
6
|
Cohen A, Patsha A, Mohapatra PK, Kazes M, Ranganathan K, Houben L, Oron D, Ismach A. Growth-Etch Metal-Organic Chemical Vapor Deposition Approach of WS 2 Atomic Layers. ACS Nano 2021; 15:526-538. [PMID: 33356120 DOI: 10.1021/acsnano.0c05394] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Metal-organic chemical vapor deposition (MOCVD) is one of the main methodologies used for thin-film fabrication in the semiconductor industry today and is considered one of the most promising routes to achieve large-scale and high-quality 2D transition metal dichalcogenides (TMDCs). However, if special measures are not taken, MOCVD suffers from some serious drawbacks, such as small domain size and carbon contamination, resulting in poor optical and crystal quality, which may inhibit its implementation for the large-scale fabrication of atomic-thin semiconductors. Here we present a growth-etch MOCVD (GE-MOCVD) methodology, in which a small amount of water vapor is introduced during the growth, while the precursors are delivered in pulses. The evolution of the growth as a function of the amount of water vapor, the number and type of cycles, and the gas composition is described. We show a significant domain size increase is achieved relative to our conventional process. The improved crystal quality of WS2 (and WSe2) domains wasis demonstrated by means of Raman spectroscopy, photoluminescence (PL) spectroscopy, and HRTEM studies. Moreover, time-resolved PL studies show very long exciton lifetimes, comparable to those observed in mechanically exfoliated flakes. Thus, the GE-MOCVD approach presented here may facilitate their integration into a wide range of applications.
Collapse
Affiliation(s)
- Assael Cohen
- Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel
| | - Avinash Patsha
- Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel
| | - Pranab K Mohapatra
- Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel
| | | | - Kamalakannan Ranganathan
- Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel
| | | | | | - Ariel Ismach
- Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel
| |
Collapse
|
7
|
Kim D, Oh GH, Kim A, Shin C, Park J, Kim SI, Kim T. Atomic Layer MoS 2xTe 2(1-x) Ternary Alloys: Two-Dimensional van der Waals Growth, Band gap Engineering, and Electrical Transport. ACS Appl Mater Interfaces 2020; 12:40518-40524. [PMID: 32808524 DOI: 10.1021/acsami.0c11154] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Ternary alloys in two-dimensional (2D) transition-metal dichalcogenides allow band gap tuning and phase engineering and change the electrical transport type. A process of 2D van der Waals epitaxial growth of molybdenum sulfide telluride alloys (MoS2xTe2(1-x), 0 ≤ x ≤ 1) is presented for synthesizing few-atomic-layer films on SiO2 substrates using metal-organic chemical vapor deposition. Raman spectra, X-ray photoelectron spectra, photoluminescence (PL), and electrical transport properties of few-atomic-layer MoS2xTe2(1-x) (0 ≤ x ≤ 1) films are systematically investigated. The strong PL peaks at 80 K from MoS2xTe2(1-x) (0.45 ≤ x ≤ 0.93) reveal a composition-controllable optical band gap (Eg = 1.55-1.91 eV at 80 K). Electrical transport properties of MoS2xTe2(1-x) alloys, where 0 ≤ x ≤ 0.8 and 0.93 ≤ x ≤ 1, exhibit p-type and n-type semiconducting behaviors, respectively. Remarkably, an increase in the Te composition of a few-atomic-layer MoS2xTe2(1-x) (0 ≤ x ≤ 1) film left-shifts the threshold voltage of a MoS2xTe2(1-x) (0 ≤ x ≤ 1) field-effect transistor. The narrower band gap energies of MoS2xTe2(1-x) films with higher Te content cause a decrease in the on/off current ratios.
Collapse
Affiliation(s)
- DongHwan Kim
- Materials and Convergence Metrology Institute, Korea Research Institute of Standards and Science, Daejeon 34113, South Korea
| | - Guen Hyung Oh
- Department of Electrical Engineering and Smart Grid Research Center, Jeonbuk National University, Jeonju 54896, South Korea
| | - Ansoon Kim
- Materials and Convergence Metrology Institute, Korea Research Institute of Standards and Science, Daejeon 34113, South Korea
| | - ChaeHo Shin
- Materials and Convergence Metrology Institute, Korea Research Institute of Standards and Science, Daejeon 34113, South Korea
| | - Jonghoo Park
- Department of Electrical Engineering, Kyungpook National University, Daegu 41566, South Korea
| | - Sang-Il Kim
- Department of Materials Science and Engineering, University of Seoul, 163 Seoulsiripdae-ro, Dongdaemun-gu, Seoul 02504, South Korea
| | - TaeWan Kim
- Department of Electrical Engineering and Smart Grid Research Center, Jeonbuk National University, Jeonju 54896, South Korea
| |
Collapse
|
8
|
Bui QC, Ardila G, Sarigiannidou E, Roussel H, Jiménez C, Chaix-Pluchery O, Guerfi Y, Bassani F, Donatini F, Mescot X, Salem B, Consonni V. Morphology Transition of ZnO from Thin Film to Nanowires on Silicon and its Correlated Enhanced Zinc Polarity Uniformity and Piezoelectric Responses. ACS Appl Mater Interfaces 2020; 12:29583-29593. [PMID: 32490666 DOI: 10.1021/acsami.0c04112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
ZnO thin films and nanostructures have received increasing interest in the field of piezoelectricity over the last decade, but their formation mechanisms on silicon when using pulsed-liquid injection metal-organic chemical vapor deposition (PLI-MOCVD) are still open to a large extent. Also, the effects of their morphology, dimensions, polarity, and electrical properties on their piezoelectric properties have not been completely decoupled yet. By only tuning the growth temperature from 400 to 750 °C while fixing the other growth conditions, the morphology transition of ZnO deposits on silicon from stacked thin films to nanowires through columnar thin films is shown. A detailed analysis of their formation mechanisms is further provided. The present transition is associated with strong enhancement of their crystallinity and growth texture along the c-axis together with a massive relaxation of the strain in nanowires. It is also related to a prevailed zinc polarity, for which its uniformity is strongly improved in nanowires. The nucleation of basal-plane stacking faults of I1-type in nanowires is also revealed and related to an emission line at about 3.326 eV in cathodoluminescence spectra, further exhibiting fairly low phonon coupling. Interestingly, the transition is additionally associated with a significant improvement of the piezoelectric amplitude, as determined by piezoresponse force microscopy measurements. The Zn-polar domains exhibit a larger piezoelectric amplitude than the O-polar domains, showing the importance of controlling the polarity in these deposits as a prerequisite to enhance the performances of piezoelectric devices. The present findings demonstrate the high potential in using the PLI-MOCVD system to form ZnO with different morphologies and polarity uniformity on silicon. They further reveal unambiguously the superiority of nanowires over thin films for piezoelectric devices.
Collapse
Affiliation(s)
- Quang Chieu Bui
- Université Grenoble Alpes, CNRS, Grenoble INP, LMGP, F-38000 Grenoble, France
- Université Grenoble Alpes, CNRS, Grenoble INP, IMEP-LAHC, F-38000 Grenoble, France
- Université Grenoble Alpes, CNRS, LTM, F-38054 Grenoble Cedex, France
| | - Gustavo Ardila
- Université Grenoble Alpes, CNRS, Grenoble INP, IMEP-LAHC, F-38000 Grenoble, France
| | | | - Hervé Roussel
- Université Grenoble Alpes, CNRS, Grenoble INP, LMGP, F-38000 Grenoble, France
| | - Carmen Jiménez
- Université Grenoble Alpes, CNRS, Grenoble INP, LMGP, F-38000 Grenoble, France
| | | | - Youssouf Guerfi
- Université Grenoble Alpes, CNRS, LTM, F-38054 Grenoble Cedex, France
| | - Franck Bassani
- Université Grenoble Alpes, CNRS, LTM, F-38054 Grenoble Cedex, France
| | - Fabrice Donatini
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut NEEL, F-38000 Grenoble, France
| | - Xavier Mescot
- Université Grenoble Alpes, CNRS, Grenoble INP, IMEP-LAHC, F-38000 Grenoble, France
| | - Bassem Salem
- Université Grenoble Alpes, CNRS, LTM, F-38054 Grenoble Cedex, France
| | - Vincent Consonni
- Université Grenoble Alpes, CNRS, Grenoble INP, LMGP, F-38000 Grenoble, France
| |
Collapse
|
9
|
Gao H, Suh J, Cao MC, Joe AY, Mujid F, Lee KH, Xie S, Poddar P, Lee JU, Kang K, Kim P, Muller DA, Park J. Tuning Electrical Conductance of MoS 2 Monolayers through Substitutional Doping. Nano Lett 2020; 20:4095-4101. [PMID: 32396734 DOI: 10.1021/acs.nanolett.9b05247] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Tuning electrical conductivity of semiconducting materials through substitutional doping is crucial for fabricating functional devices. This, however, has not been fully realized in two-dimensional (2D) materials due to the difficulty of homogeneously controlling the dopant concentrations and the lack of systematic study of the net impact of substitutional dopants separate from that of the unintentional doping from the device fabrication processes. Here, we grow wafer-scale, continuous MoS2 monolayers with tunable concentrations of Nb and Re and fabricate devices using a polymer-free approach to study the direct electrical impact of substitutional dopants in MoS2 monolayers. In particular, the electrical conductivity of Nb doped MoS2 in the absence of electrostatic gating is reproducibly tuned over 7 orders of magnitude by controlling the Nb concentration. Our study further indicates that the dopant carriers do not fully ionize in the 2D limit, unlike in their three-dimensional analogues, which is explained by weaker charge screening and impurity band conduction. Moreover, we show that the dopants are stable, which enables the doped films to be processed as independent building blocks that can be used as electrodes for functional circuitry.
Collapse
Affiliation(s)
- Hui Gao
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Department of Chemistry, Pritzker School of Molecular Engineering, and James Frank Institute, University of Chicago, Chicago, Illinois 60637, United States
| | - Joonki Suh
- Department of Chemistry, Pritzker School of Molecular Engineering, and James Frank Institute, University of Chicago, Chicago, Illinois 60637, United States
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Michael C Cao
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States
| | - Andrew Y Joe
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Fauzia Mujid
- Department of Chemistry, Pritzker School of Molecular Engineering, and James Frank Institute, University of Chicago, Chicago, Illinois 60637, United States
| | - Kan-Heng Lee
- Department of Chemistry, Pritzker School of Molecular Engineering, and James Frank Institute, University of Chicago, Chicago, Illinois 60637, United States
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States
| | - Saien Xie
- Department of Chemistry, Pritzker School of Molecular Engineering, and James Frank Institute, University of Chicago, Chicago, Illinois 60637, United States
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States
| | - Preeti Poddar
- Department of Chemistry, Pritzker School of Molecular Engineering, and James Frank Institute, University of Chicago, Chicago, Illinois 60637, United States
| | - Jae-Ung Lee
- Department of Chemistry, Pritzker School of Molecular Engineering, and James Frank Institute, University of Chicago, Chicago, Illinois 60637, United States
- Department of Physics, Ajou University, Suwon 16499, Korea
| | - Kibum Kang
- Department of Chemistry, Pritzker School of Molecular Engineering, and James Frank Institute, University of Chicago, Chicago, Illinois 60637, United States
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Philip Kim
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
| | - David A Muller
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States
| | - Jiwoong Park
- Department of Chemistry, Pritzker School of Molecular Engineering, and James Frank Institute, University of Chicago, Chicago, Illinois 60637, United States
| |
Collapse
|
10
|
Kim DY, Jeong H, Kim J, Han N, Kim JK. Defect-Mediated In-Plane Electrical Conduction in Few-Layer sp 2-Hybridized Boron Nitrides. ACS Appl Mater Interfaces 2018; 10:17287-17294. [PMID: 29701455 DOI: 10.1021/acsami.8b04389] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In-plane electrical conduction in sp2-hybridized boron nitride (sp2-BN) is presented to explore a huge potential of sp2-BN as an active material for electronics and ultraviolet optoelectronics. Systematic investigation on temperature-dependent current-voltage ( I- V) characteristics of a few-layer sp2-BN grown by metal-organic vapor-phase epitaxy reveals two types of predominant conduction mechanisms that are Ohmic conduction at the low bias region and space-charge-limited conduction at the high bias region. From the temperature-dependent I- V characteristics, two shallow traps with activation energies of approximately 25 and 185 meV are observed. On the basis of the near-edge X-ray absorption fine-structure spectroscopy, boron-boron (B-B) homoelemental bonding which can be related to grain boundary and nitrogen vacancy (VN) are proposed as the origin of the shallow traps mediating the in-plane conduction in the sp2-BN layer. In addition, a drastic enhancement in the electrical conductivity is observed with the increasing amount of VN that acts as a donor, implying that controlled generation of VN can be an alternative and better approach for the n-type doping of the sp2-BN film rather than ineffective conventional substitutional doping methods.
Collapse
Affiliation(s)
- Dong Yeong Kim
- Department of Materials Science and Engineering , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea
| | - Hokyeong Jeong
- Department of Materials Science and Engineering , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea
| | - Jaewon Kim
- Department of Materials Science and Engineering , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea
| | - Nam Han
- Department of Materials Science and Engineering , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea
| | - Jong Kyu Kim
- Department of Materials Science and Engineering , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea
| |
Collapse
|
11
|
Schipper DE, Zhao Z, Leitner AP, Xie L, Qin F, Alam MK, Chen S, Wang D, Ren Z, Wang Z, Bao J, Whitmire KH. A TiO 2/FeMnP Core/Shell Nanorod Array Photoanode for Efficient Photoelectrochemical Oxygen Evolution. ACS Nano 2017; 11:4051-4059. [PMID: 28333437 DOI: 10.1021/acsnano.7b00704] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A variety of catalysts have recently been developed for electrocatalytic oxygen evolution, but very few of them can be readily integrated with semiconducting light absorbers for photoelectrochemical or photocatalytic water splitting. Here, we demonstrate an efficient core/shell photoanode with a highly active oxygen evolution electrocatalyst shell (FeMnP) and semiconductor core (rutile TiO2) for photoelectrochemical oxygen evolution reaction. Metal-organic chemical vapor deposition from a single-source precursor was used to ensure good contact between the FeMnP and the TiO2. The TiO2/FeMnP core/shell photoanode reaches the theoretical photocurrent density for rutile TiO2 of 1.8 mA cm-2 at 1.23 V vs reversible hydrogen electrode under simulated 100 mW cm-2 (1 sun) irradiation. The dramatic enhancement is a result of the synergistic effects of the high oxygen evolution reaction activity of FeMnP (delivering an overpotential of 300 mV with a Tafel slope of 65 mV dec-1 in 1 M KOH) and the conductive interlayer between the surface active sites and semiconductor core which boosts the interfacial charge transfer and photocarrier collection. The facile fabrication of the TiO2/FeMnP core/shell nanorod array photoanode offers a compelling strategy for preparing highly efficient photoelectrochemical solar energy conversion devices.
Collapse
Affiliation(s)
- Desmond E Schipper
- Department of Chemistry, MS60, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Zhenhuan Zhao
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China , Chengdu 610054, China
| | - Andrew P Leitner
- Department of Chemistry, MS60, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | | | | | | | | | | | | | - Zhiming Wang
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China , Chengdu 610054, China
| | - Jiming Bao
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China , Chengdu 610054, China
| | - Kenton H Whitmire
- Department of Chemistry, MS60, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| |
Collapse
|
12
|
Ji X, Yang X, Du W, Pan H, Yang T. Selective-Area MOCVD Growth and Carrier-Transport-Type Control of InAs(Sb)/GaSb Core-Shell Nanowires. Nano Lett 2016; 16:7580-7587. [PMID: 27960521 DOI: 10.1021/acs.nanolett.6b03429] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report the first selective-area growth of high quality InAs(Sb)/GaSb core-shell nanowires on Si substrates using metal-organic chemical vapor deposition (MOCVD) without foreign catalysts. Transmission electron microscopy (TEM) analysis reveals that the overgrowth of the GaSb shell is highly uniform and coherent with the InAs(Sb) core without any misfit dislocations. To control the structural properties and reduce the planar defect density in the self-catalyzed InAs core nanowires, a trace amount of Sb was introduced during their growth. As the Sb content increases from 0 to 9.4%, the crystal structure of the nanowires changes from a mixed wurtzite (WZ)/zinc-blende (ZB) structure to a perfect ZB phase. Electrical measurements reveal that both the n-type InAsSb core and p-type GaSb shell can work as active carrier transport channels, and the transport type of core-shell nanowires can be tuned by the GaSb shell thickness and back-gate voltage. This study furthers our understanding of the Sb-induced crystal-phase control of nanowires. Furthermore, the high quality InAs(Sb)/GaSb core-shell nanowire arrays obtained here pave the foundation for the fabrication of the vertical nanowire-based devices on a large scale and for the study of fundamental quantum physics.
Collapse
Affiliation(s)
- Xianghai Ji
- Key Laboratory of Semiconductor Materials Science, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences , Beijing 100083, People's Republic of China
| | - Xiaoguang Yang
- Key Laboratory of Semiconductor Materials Science, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences , Beijing 100083, People's Republic of China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| | - Wenna Du
- Key Laboratory of Semiconductor Materials Science, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences , Beijing 100083, People's Republic of China
| | - Huayong Pan
- Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University , Beijing 100871, People's Republic of China
| | - Tao Yang
- Key Laboratory of Semiconductor Materials Science, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences , Beijing 100083, People's Republic of China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| |
Collapse
|