1
|
Kwon DS, Bizindavyi J, De G, Belmonte A, Delabie A, Nyns L, Kar GS, Van Houdt J, Popovici MI. Improvement of the Ferroelectric Response of La-Doped Hafnium Zirconium Oxide Employing Tungsten Oxide Interfacial Layer with Back-End-of-Line Compatibility. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 39056583 DOI: 10.1021/acsami.4c08988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
In this work, the impact of a tungsten oxide (WO3) seed and capping layer for ferroelectric La-doped (Hf, Zr)O2 (La:HZO) based capacitors, designed with back-end-of-line (BEOL) compatibility, is systematically investigated. The WO3 capping layer supplies oxygen to the La:HZO layer throughout the fabrication process and during device cycling. This facilitates the annihilation of oxygen vacancies (Vo) within the La:HZO layer, thereby stabilizing its ferroelectric orthorhombic phase and resulting in an increase of the remanent polarization (Pr) value in the capacitor. Moreover, the effectiveness of the WO3 capping layer depends on the seed layer of the HZO film, suggesting that proper combination of the seed and capping layers should be employed to maximize the ferroelectric response. Finally, a TiN/TiO2 seed layer/La:HZO/WO3 capping layer/TiN capacitor is successfully fabricated and optimized by a complete set of atomic layer deposition (ALD) processes, achieving a superior 2Pr value and endurance value of more than 109 cycles at an electric field of 2.5 MV/cm. The WO3 capping layer is anticipated to offer a viable solution for doped HZO capacitors with reduced thickness, addressing the challenge of elevated Vo levels that favor the tetragonal phase and result in low 2Pr values.
Collapse
Affiliation(s)
| | | | - Gourab De
- imec, Kapeldreef 75, 3001 Leuven, Belgium
- KU Leuven, Celestijnenlaan 200, 3001 Leuven, Belgium
| | | | - Annelies Delabie
- imec, Kapeldreef 75, 3001 Leuven, Belgium
- KU Leuven, Celestijnenlaan 200, 3001 Leuven, Belgium
| | - Laura Nyns
- imec, Kapeldreef 75, 3001 Leuven, Belgium
| | | | - Jan Van Houdt
- imec, Kapeldreef 75, 3001 Leuven, Belgium
- KU Leuven, Celestijnenlaan 200, 3001 Leuven, Belgium
| | | |
Collapse
|
2
|
Pujar P, Cho H, Kim YH, Zagni N, Oh J, Lee E, Gandla S, Nukala P, Kim YM, Alam MA, Kim S. An Aqueous Route to Oxygen-Deficient Wake-Up-Free La-Doped HfO 2 Ferroelectrics for Negative Capacitance Field Effect Transistors. ACS NANO 2023; 17:19076-19086. [PMID: 37772990 DOI: 10.1021/acsnano.3c04983] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
The crucial role of nanocrystalline morphology in stabilizing the ferroelectric orthorhombic (o)-phase in doped-hafnia films is achieved via chemical solution deposition (CSD) by intentionally retaining carbonaceous impurities to inhibit grain growth. However, in the present study, large-grained (>100 nm) La-doped HfO2 (HLO) films are grown directly on silicon by adopting engineered water-diluted precursors with a minimum carbonaceous load and excellent shelf life. The o-phase stabilization is accomplished through a well-distributed La dopant, which generates uniformly populated oxygen vacancies, eliminating the need for oxygen-scavenging electrodes. These oxygen-deficient HLOs show a maximum remnant polarization of 37.6 μC/cm2 (2Pr) without wake-up and withstand large fields (>6.2 MV/cm). Furthermore, CSD-HLO in series with Al2O3 improves switching of MOSFETs (with an amorphous oxide channel) based on the negative capacitance effect. Thus, uniformly distributed oxygen vacancies serve as a standalone factor in stabilizing the o-phase, enabling efficient wake-up-free ferroelectricity without the need for nanostructuring, capping stresses, or oxygen-reactive electrodes.
Collapse
Affiliation(s)
- Pavan Pujar
- Department of Ceramic Engineering, Indian Institute of Technology (IIT-BHU), Varanasi, Uttar Pradesh 221005, India
| | - Haewon Cho
- Multifunctional Nano Bio Electronics Lab, School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, Gyeonggi-do, Republic of Korea
| | - Young-Hoon Kim
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Nicolò Zagni
- Department of Engineering "Enzo Ferrari" (DIEF), University of Modena and Reggio Emilia, Modena 41125, Italy
| | - Jeonghyeon Oh
- Multifunctional Nano Bio Electronics Lab, School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, Gyeonggi-do, Republic of Korea
| | - Eunha Lee
- Analytical Engineering Group, Samsung Advanced Institute of Technology (SAIT), Samsung Electronics, Suwon 16678 Republic of Korea
| | - Srinivas Gandla
- Multifunctional Nano Bio Electronics Lab, School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, Gyeonggi-do, Republic of Korea
| | - Pavan Nukala
- Centre for Nano Science and Engineering, Indian Institute of Science, Bengaluru 560012, India
| | - Young-Min Kim
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Muhammad Ashraful Alam
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Sunkook Kim
- Multifunctional Nano Bio Electronics Lab, School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, Gyeonggi-do, Republic of Korea
| |
Collapse
|
3
|
Kim MK, Kim IJ, Lee JS. Defect Engineering of Hafnia-Based Ferroelectric Materials for High-Endurance Memory Applications. ACS OMEGA 2023; 8:18180-18185. [PMID: 37251138 PMCID: PMC10210041 DOI: 10.1021/acsomega.3c01561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 04/24/2023] [Indexed: 05/31/2023]
Abstract
Zirconium-doped hafnium oxide (HfZrOx) is one of the promising ferroelectric materials for next-generation memory applications. To realize high-performance HfZrOx for next-generation memory applications, the formation of defects in HfZrOx, including oxygen vacancies and interstitials, needs to be optimized, as it can affect the polarization and endurance characteristics of HfZrOx. In this study, we investigated the effects of ozone exposure time during the atomic layer deposition (ALD) process on the polarization and endurance characteristics of 16-nm-thick HfZrOx. HfZrOx films showed different polarization and endurance characteristics depending on the ozone exposure time. HfZrOx deposited using the ozone exposure time of 1 s showed small polarization and large defect concentration. The increase of the ozone exposure time to 2.5 s could reduce the defect concentration and improve the polarization characteristics of HfZrOx. When the ozone exposure time further increased to 4 s, a reduction of polarization was observed in HfZrOx due to the formation of oxygen interstitials and non-ferroelectric monoclinic phases. HfZrOx, with an ozone exposure time of 2.5 s, exhibited the most stable endurance characteristics because of the low initial defect concentration in HfZrOx, which was confirmed by the leakage current analysis. This study shows that the ozone exposure time of ALD needs to be controlled to optimize the formation of defects in HfZrOx films for the improvement of polarization and endurance characteristics.
Collapse
|
4
|
Park JY, Lee DH, Park GH, Lee J, Lee Y, Park MH. A perspective on the physical scaling down of hafnia-based ferroelectrics. NANOTECHNOLOGY 2023; 34:202001. [PMID: 36745914 DOI: 10.1088/1361-6528/acb945] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 02/05/2023] [Indexed: 06/18/2023]
Abstract
HfO2-based ferroelectric thin films have attracted significant interest for semiconductor device applications due to their compatibility with complementary metal oxide semiconductor (CMOS) technology. One of the benefits of HfO2-based ferroelectric thin films is their ability to be scaled to thicknesses as low as 10 nm while retaining their ferroelectric properties; a feat that has been difficult to accomplish with conventional perovskite-based ferroelectrics using CMOS-compatible processes. However, reducing the thickness limit of HfO2-based ferroelectric thin films below the sub 5 nm thickness regime while preserving their ferroelectric property remains a formidable challenge. This is because both the structural factors of HfO2, including polymorphism and orientation, and the electrical factors of HfO2-based devices, such as the depolarization field, are known to be highly dependent on the HfO2thickness. Accordingly, when the thickness of HfO2drops below 5 nm, these factors will become even more crucial. In this regard, the size effect of HfO2-based ferroelectric thin films is thoroughly discussed in the present review. The impact of thickness on the ferroelectric property of HfO2-based thin films and the electrical performance of HfO2-based ferroelectric semiconductor devices, such as ferroelectric random-access-memory, ferroelectric field-effect-transistor, and ferroelectric tunnel junction, is extensively discussed from the perspective of fundamental theory and experimental results. Finally, recent developments and reports on achieving ferroelectric HfO2at sub-5 nm thickness regime and their applications are discussed.
Collapse
Affiliation(s)
- Ju Yong Park
- Department of Materials Science and Engineering & Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Dong Hyun Lee
- Department of Materials Science and Engineering & Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Geun Hyeong Park
- Department of Materials Science and Engineering & Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Jaewook Lee
- Department of Materials Science and Engineering & Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Younghwan Lee
- Research Institute of Advanced Materials, College of Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Min Hyuk Park
- Department of Materials Science and Engineering & Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
- Research Institute of Advanced Materials, College of Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Republic of Korea
| |
Collapse
|
5
|
Nguyen AHT, Nguyen MC, Nguyen AD, Yim JY, Kim JH, Park NH, Jeon SJ, Kwon D, Choi R. Impact of Pt grain size on ferroelectric properties of zirconium hafnium oxide by chemical solution deposition. NANO CONVERGENCE 2022; 9:45. [PMID: 36197530 PMCID: PMC9535072 DOI: 10.1186/s40580-022-00334-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
The effects of the grain size of Pt bottom electrodes on the ferroelectricity of hafnium zirconium oxide (HZO) were studied in terms of the orthorhombic phase transformation. HZO thin films were deposited by chemical solution deposition on the Pt bottom electrodes with various grain sizes which had been deposited by direct current sputtering. All the samples were crystallized by rapid thermal annealing at 700 °C to allow a phase transformation. The crystallographic phases were determined by grazing incidence X-ray diffraction, which showed that the bottom electrode with smaller Pt grains resulted in a larger orthorhombic phase composition in the HZO film. As a result, capacitors with smaller Pt grains for the bottom electrode showed greater ferroelectric polarization. The smaller grains produced larger in-plane stress which led to more orthorhombic phase transformation and higher ferroelectric polarization.
Collapse
Affiliation(s)
- An Hoang-Thuy Nguyen
- Department of Materials Science and Engineering, Inha University, Incheon, 22212, South Korea
| | - Manh-Cuong Nguyen
- Department of Electrical Engineering at, Inha University, Incheon, 22212, South Korea
| | - Anh-Duy Nguyen
- Department of Materials Science and Engineering, Inha University, Incheon, 22212, South Korea
| | - Ji-Yong Yim
- Department of Electrical Engineering at, Inha University, Incheon, 22212, South Korea
| | - Jeong-Han Kim
- Department of Electrical Engineering at, Inha University, Incheon, 22212, South Korea
| | - No-Hwal Park
- 3D Convergence Center at Inha University, Incheon, 22212, South Korea
| | - Seung-Joon Jeon
- 3D Convergence Center at Inha University, Incheon, 22212, South Korea
| | - Daewoong Kwon
- Department of Electrical Engineering at, Inha University, Incheon, 22212, South Korea.
| | - Rino Choi
- Department of Materials Science and Engineering, Inha University, Incheon, 22212, South Korea.
| |
Collapse
|
6
|
Liao CY, Hsiang KY, Lou ZF, Lin CY, Tseng YJ, Tseng HC, Li ZX, Ray WC, Chang FS, Wang CC, Chen TC, Chang CS, Lee MH. Multipeak Coercive Electric-Field-Based Multilevel Cell Nonvolatile Memory With Antiferroelectric-Ferroelectric Field-Effect Transistors (FETs). IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:2214-2221. [PMID: 35380960 DOI: 10.1109/tuffc.2022.3165047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
An ultralow program/erase voltage ( |VP/E| = 4 V) is demonstrated by using an antiferroelectric-ferroelectric field-effect transistor (AFE-FE-FET) through a multipeak coercive E -field ( EC ) concept for a four-level stable state with outstanding endurance (>105 cycles) and data retention (>104 s at 65 °C). The mixture of ferroelectric (FE) and AFE domains can provide stable multistate and data storage with zero bias for multilevel cell (MLC) applications. HfZrO2 (HZO) with AFE-FE assembles an orthorhombic/tetragonal (o/t) phase composition and is achieved by [Zr] modulation in an HZO system. MLC characteristics not only improve high-density nonvolatile memory (NVM) but are also beneficial to neuromorphic device applications.
Collapse
|
7
|
Banerjee W, Kashir A, Kamba S. Hafnium Oxide (HfO 2 ) - A Multifunctional Oxide: A Review on the Prospect and Challenges of Hafnium Oxide in Resistive Switching and Ferroelectric Memories. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2107575. [PMID: 35510954 DOI: 10.1002/smll.202107575] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 03/24/2022] [Indexed: 06/14/2023]
Abstract
Hafnium oxide (HfO2 ) is one of the mature high-k dielectrics that has been standing strong in the memory arena over the last two decades. Its dielectric properties have been researched rigorously for the development of flash memory devices. In this review, the application of HfO2 in two main emerging nonvolatile memory technologies is surveyed, namely resistive random access memory and ferroelectric memory. How the properties of HfO2 equip the former to achieve superlative performance with high-speed reliable switching, excellent endurance, and retention is discussed. The parameters to control HfO2 domains are further discussed, which can unleash the ferroelectric properties in memory applications. Finally, the prospect of HfO2 materials in emerging applications, such as high-density memory and neuromorphic devices are examined, and the various challenges of HfO2 -based resistive random access memory and ferroelectric memory devices are addressed with a future outlook.
Collapse
Affiliation(s)
- Writam Banerjee
- Center for Single Atom-based Semiconductor Device, Department of Material Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Alireza Kashir
- Institute of Physics of the Czech Academy of Sciences, Na Slovance 2, Prague 8, 182 21, Czech Republic
| | - Stanislav Kamba
- Institute of Physics of the Czech Academy of Sciences, Na Slovance 2, Prague 8, 182 21, Czech Republic
| |
Collapse
|
8
|
Choi Y, Han C, Shin J, Moon S, Min J, Park H, Eom D, Lee J, Shin C. Impact of Chamber/Annealing Temperature on the Endurance Characteristic of Zr:HfO 2 Ferroelectric Capacitor. SENSORS (BASEL, SWITZERLAND) 2022; 22:s22114087. [PMID: 35684705 PMCID: PMC9185304 DOI: 10.3390/s22114087] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/20/2022] [Accepted: 05/24/2022] [Indexed: 06/01/2023]
Abstract
The endurance characteristic of Zr-doped HfO2 (HZO)-based metal-ferroelectric-metal (MFM) capacitors fabricated under various deposition/annealing temperatures in the atomic layer deposition (ALD) process was investigated. The chamber temperature in the ALD process was set to 120 °C, 200 °C, or 250 °C, and the annealing temperature was set to 400 °C, 500 °C, 600 °C, or 700 °C. For the given annealing temperature of 700 °C, the remnant polarization (2Pr) was 17.21 µC/cm2, 26.37 µC/cm2, and 31.8 µC/cm2 at the chamber temperatures of 120 °C, 200 °C, and 250 °C, respectively. For the given/identical annealing temperature, the largest remnant polarization (Pr) was achieved when using the chamber temperature of 250 °C. At a higher annealing temperature, the grain size in the HZO layer becomes smaller, and thereby, it enables to boost up Pr. It was observed that the endurance characteristics for the capacitors fabricated under various annealing/chamber temperatures were quite different. The different endurance characteristics are due to the oxygen and oxygen vacancies in ferroelectric films, which affects the wakeup/fatigue behaviors. However, in common, all the capacitors showed no breakdown for an externally applied pulse (up to 108 cycles of the pulse).
Collapse
Affiliation(s)
- Yejoo Choi
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea; (Y.C.); (C.H.); (S.M.); (H.P.)
| | - Changwoo Han
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea; (Y.C.); (C.H.); (S.M.); (H.P.)
| | - Jaemin Shin
- Department of Electrical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA;
| | - Seungjun Moon
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea; (Y.C.); (C.H.); (S.M.); (H.P.)
| | - Jinhong Min
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Hyeonjung Park
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea; (Y.C.); (C.H.); (S.M.); (H.P.)
| | - Deokjoon Eom
- School of Advanced Materials Sciences and Engineering, Sungkyunkwan University, Suwon 16419, Korea; (D.E.); (J.L.)
| | - Jehoon Lee
- School of Advanced Materials Sciences and Engineering, Sungkyunkwan University, Suwon 16419, Korea; (D.E.); (J.L.)
| | - Changhwan Shin
- School of Electrical Engineering, Korea University, Seoul 02841, Korea
| |
Collapse
|
9
|
Unipolar Parity of Ferroelectric-Antiferroelectric Characterized by Junction Current in Crystalline Phase Hf 1-xZr xO 2 Diodes. NANOMATERIALS 2021; 11:nano11102685. [PMID: 34685126 PMCID: PMC8541604 DOI: 10.3390/nano11102685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/04/2021] [Accepted: 10/06/2021] [Indexed: 11/21/2022]
Abstract
Ferroelectric (FE) Hf1−xZrxO2 is a potential candidate for emerging memory in artificial intelligence (AI) and neuromorphic computation due to its non-volatility for data storage with natural bi-stable characteristics. This study experimentally characterizes and demonstrates the FE and antiferroelectric (AFE) material properties, which are modulated from doped Zr incorporated in the HfO2-system, with a diode-junction current for memory operations. Unipolar operations on one of the two hysteretic polarization branch loops of the mixed FE and AFE material give a low program voltage of 3 V with an ON/OFF ratio >100. This also benefits the switching endurance, which reaches >109 cycles. A model based on the polarization switching and tunneling mechanisms is revealed in the (A)FE diode to explain the bipolar and unipolar sweeps. In addition, the proposed FE-AFE diode with Hf1−xZrxO2 has a superior cycling endurance and lower stimulation voltage compared to perovskite FE-diodes due to its scaling capability for resistive FE memory devices.
Collapse
|
10
|
Kim HB, Jung M, Oh Y, Lee SW, Suh D, Ahn JH. Superior and stable ferroelectric properties of hafnium-zirconium-oxide thin films deposited via atomic layer deposition using cyclopentadienyl-based precursors without annealing. NANOSCALE 2021; 13:8524-8530. [PMID: 33908540 DOI: 10.1039/d1nr01535d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
HfO2-based ferroelectric thin films deposited via atomic layer deposition have been extensively studied as promising candidates for next-generation ferroelectric devices. The conversion of an amorphous Hf1-xZrxO2 film to the ferroelectric phase (non-centrosymmetric orthorhombic phase) has been achieved through annealing using a post-thermal process. However, in this study, we present the first report of ferroelectricity of hafnium-zirconium-oxide (HZO) thin films deposited via atomic layer deposition using cyclopentadienyl-based precursors without additional post-thermal processing. By increasing the deposition temperature using a cyclopentadienyl-based cocktail precursor, the conditions of the as-deposited HZO thin film to crystallize well with an orthorhombic phase were secured, and excellent ferroelectric properties with a large remanent polarization (2Pr ∼ 47.6 μC cm-2) were implemented without crystallization annealing. The as-deposited HZO thin film possessed very stable ferroelectric properties without a wake-up effect or significant fatigue up to 106 cycles. Futhermore, we demonstrated the applicability to devices using negative capacitance and non-volatile memory characteristics. This result suggests that a new strategy can be applied to ferroelectric devices where subsequent processing temperature constraints are required, such as back-end-of-line processes and ferroelectric-based flexible device applications.
Collapse
Affiliation(s)
- Hyo-Bae Kim
- Department of Materials Science and Chemical Engineering, Hanyang University, Ansan 15588, Republic of Korea.
| | - Moonyoung Jung
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea.
| | - Youkyoung Oh
- Department of Materials Science and Chemical Engineering, Hanyang University, Ansan 15588, Republic of Korea.
| | - Seung Won Lee
- Department of Materials Science and Chemical Engineering, Hanyang University, Ansan 15588, Republic of Korea.
| | - Dongseok Suh
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea.
| | - Ji-Hoon Ahn
- Department of Materials Science and Chemical Engineering, Hanyang University, Ansan 15588, Republic of Korea.
| |
Collapse
|