Article
Engineering, Environmental
Gaoshuang He, Jie Li, Weixin Qiu, Long Chen, Keke Wang, Yang Liu, Min Liu, Wenzhang Li
Summary: To improve the PEC performance of α-SnWO4 photoanode, the atomic ratio of Sn and W on the surface is adjusted by exposing the photoanode to a Sn2+ or H+-rich microenvironment. Increasing the tin content on the surface facilitates charge separation and improves water oxidation reaction compared to the W atom. The tin-rich SnWO4 photoanode shows a 2-fold increase in photocurrent density compared to the tin-poor SnWO4 material, making it the state-of-the-art photocurrent density.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Shankara S. Kalanur, Young Jae Lee, Hyungtak Seo
Summary: The study introduces a versatile BiVO4 thin film synthesis strategy that allows for morphology tunability, feasibility of doping, and heterojunction formation in a single step. This strategy can be extended to fabricate different nanostructures by changing capping agents, and has shown the feasibility of Al doping and heterojunction formation with WO3 nanostructure for enhanced PEC activity. The proposed strategy could be exploited using new capping agents and dopants for simultaneously obtaining doped BiVO4 in heterojunction systems with unique morphology.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Fatma Zakaria Salem, M. A. Ahmed, M. A. Sadek, Maryam G. Elmahgary
Summary: This study investigates the controllable properties of SrSnO3 perovskite as a catalyst for photocatalytic water splitting using computational analysis. The synergistic effect of hydrogen doping and oxygen vacancies on the optoelectronic properties is discussed. The results show that interstitial hydrogen defects introduce shallow defect states and increase the dielectric constant, while the HOV-OV structural configuration significantly enhances optical absorption and permittivity at high concentrations of oxygen vacancies, making it an ideal catalyst for photocatalytic water splitting.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Nanoscience & Nanotechnology
Long Chen, Wenzhang Li, Weixin Qiu, Gaoshuang He, Keke Wang, Yang Liu, Qing Wu, Jie Li
Summary: Modulating the exposed facets of copper tungstate films can enhance the photoelectrochemical properties, resulting in improved charge transport, reduced recombination of electrons and holes, promoted oxygen evolution reaction, and better stability.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Wen Lei, Yingjie Yu, Haijun Zhang, Quanli Jia, Shaowei Zhang
Summary: This paper summarizes recent developments in using various techniques to introduce, characterize, and regulate defects in defect engineering. The important role of defects in high-performance defect engineered photoelectrodes for PEC water splitting application is highlighted. Current challenges and future perspectives in the field of defect engineering of nanostructures for photoelectrodes are also discussed.
Article
Chemistry, Physical
Jihun Kang, Ki-Yong Yoon, Jae-Eun Lee, Juhyung Park, Sourav Chaule, Ji-Hyun Jang
Summary: For the first time, a simple in-situ phosphorus (P) doping strategy was used to improve the photoelectrochemical water splitting (PEC) performance of hematite. The introduction of FePO4 regions on the Ti-doped FeOOH surface and subsequent high-temperature annealing resulted in the fabrication of mesoporous P,Ti co-doped Fe2O3 nanorods. The resulting P,Ti-Fe2O3 photoanode exhibited significantly improved photo-current density, and with the deposition of the NiFeOx cocatalyst, it achieved excellent photocurrent density with a remarkable cathodic shift of the onset potential.
Article
Chemistry, Physical
Shrinath Dattatray Ghadge, Moni K. Datta, Oleg Velikokhatnyi, Prashant N. Kumta
Summary: This study presents a simple and effective Mo doping approach for generating high-performance photoanodes for PEC water splitting. Mo doping can enhance light absorption ability, reduce band gap, increase carrier density and photocurrent density, while also decreasing charge transfer resistance and improving PEC stability.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Weiwei Xu, Wei Tian, Linxing Meng, Fengren Cao, Liang Li
Summary: Introducing In-O-Cd bond at the interface of ZnIn2S4/CdS heterojunction successfully converts the band structure and accelerates surface reaction kinetics, resulting in enhanced PEC performance.
ADVANCED ENERGY MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Ahmed Chnani, Steffen Strehle
Summary: Hematite, a low-cost, nontoxic, and earth-abundant semiconductor, is still a promising photoanode material for PEC water splitting, but its PEC performance is hindered by fast charge carrier recombination rates and short diffusion lengths. Nanostructure implementation has been proposed to overcome this limitation and improve photon harvesting efficiency, but unmodified nanostructures may actually decrease the performance of PEC electrodes due to lack of internal electrical splitting fields.
ACS APPLIED NANO MATERIALS
(2022)
Review
Energy & Fuels
Caihong Cheng, Weiying Zhang, Xiaoming Chen, Shaoqin Peng, Yuexiang Li
Summary: Silicon, as a narrow bandgap semiconductor with broad absorption for sunlight, is considered a competitive material for solar-driven photoelectrochemical water splitting. However, major barriers such as low photovoltage, sluggish kinetics, and poor stability exist in constructing efficient and stable Si-based PEC cells. Strategies to enhance Si-based photoelectrode performance include regulating surface morphology, engineering band structure, and modifying protection layers. Issues of Si-based photoelectrode materials for future research are also highlighted in this review.
ENERGY SCIENCE & ENGINEERING
(2022)
Article
Chemistry, Physical
Burcu Oral, Elif Can, Ramazan Yildirim
Summary: In this study, machine learning techniques were used to analyze an extensive dataset on photoelectrochemical water splitting over n-type semiconductors. The results showed that association rule mining, decision tree, and random forest could identify patterns and establish relations between photocurrent density and various descriptors.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Xiaoqian Huang, Ruikang Zhang, Xiaoru Gao, Borong Yu, Yuanzhe Gao, Zhan-gang Han
Summary: TiO2-R/A homojunction photoanode, fabricated by in situ growth of anatase TiO2 on TiO2-R surface, displays higher photocurrent density compared to TiO2-R/R photoanode. The intense band bending and enhanced surface area of TiO2-R/A homojunction facilitate charge separation and transmission, providing novel insights for designing and fabricating semiconductor photoanodes for highly efficient photocatalytic reactions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
D. Amaranatha Reddy, Yujin Kim, Pooja Varma, Madhusudana Gopannagari, K. Arun Joshi Reddy, Da Hye Hong, Inae Song, D. Praveen Kumar, Tae Kyu Kim
Summary: This paper introduces an inverse opal-like structured photocathode fabricated using a layered self-assembly approach for photoelectrochemical water-splitting cells. The photocathode has an interconnected macroporous structure that enhances visible-light-harvesting capabilities and improves charge-carrier transport properties. The optimized photocathodes showed high photocurrent density and stability, as well as exceptional photon harvesting and quantum yields.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Physical
Jiachao Wu, Jun Wei, Bing Lv, Mingjun Wang, Xiaolu Wang, Wenzhong Wang
Summary: One-dimensional/zero-dimensional CdS/In2S3 nanorod arrays were successfully constructed by depositing In2S3 nanoparticles on 1D CdS nanorod arrays. The constructed CdS/In2S3 nanorod arrays show significantly enhanced photocurrent density under simulated solar light.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Pannan Kyesmen, Nolwazi Nombona, Mmantsae Diale
Summary: This research focused on preparing nanostructured heterojunction of alpha-Fe2O3 and porous CuO composites as photoanodes for PEC water splitting. The formations of heterojunction and porous surface morphology facilitated charge separation and enhanced PEC efficiency. The reduced bandgap and increased photon absorption in the visible spectrum were key factors in improving photocurrent density.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Ceramics
Thi Kim Thoa Huynh, Youngjae Lee, Shankara S. Kalanur, Hyungtak Seo
Summary: The study demonstrated the use of sputtering technique to coat 1-D TiO2 with a SnO2 nanolayer for surface engineering, enhancing solar water splitting activity. The optimized SnO2/TiO2 system exhibited high photocurrent, incident photon to current efficiency, and hydrogen and oxygen production efficiency.
CERAMICS INTERNATIONAL
(2022)
Article
Nanoscience & Nanotechnology
Hojun Seo, Sang Yeon Lee, Jeongsu Lee, Sunjin Kim, Onejae Sul, Hyungtak Seo, Seung-Beck Lee
Summary: A low-temperature process is demonstrated to transform insulating In2O3 thin-films into n-type semiconductors, enabling the development of high-performance In2O3 thin-film transistors. The H-plasma assisted annealing process, compared to thermal annealing, not only reduces processing time but also maintains the insulating nature of the untreated area.
Article
Chemistry, Multidisciplinary
Mohit Kumar, Yeong Hwan Ahn, Shahid Iqbal, Unjeong Kim, Hyungtak Seo
Summary: Emerging nonvolatile resistive switching, or memristors, rely on the composition change of active materials rather than storing charge. By stabilizing the conduction channel through manipulation of oxygen defects using electron-beam irradiation, high-performance memristor devices with adjustable switching ratios are fabricated, showcasing broad modulation of neural activities.
Article
Nanoscience & Nanotechnology
Qadeer Akbar Sial, Mohit Kumar, Shahid Iqbal, Shankara S. Kalanur, Hyungtak Seo
Summary: In this study, an acid-sensitive artificial nociceptor device is developed for electronic nose application, which can detect acid concentration and generate synaptic signals, demonstrating memory storage ability and tunability.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Le Thai Duy, Qadeer Akbar Sial, Hyungtak Seo
Summary: The study focused on utilizing a stretchable composite based on carbon nanotubes and polydimethylsiloxane for textile-based supercapacitors, exploring the positive and negative effects of washing. Strategies utilizing molybdenum trioxide nanoflakes were designed to enhance the composite's performance, showing potential for improved energy and power densities. Additionally, chemical treatment with a liquid detergent was found to significantly enhance the performance of supercapacitor electrodes.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Chemistry, Multidisciplinary
Eunji Ji, Jong Hun Kim, Wanggon Lee, June-Chul Shin, Hyungtak Seo, Kyuwook Ihm, Jin-Woo Park, Gwan-Hyoung Lee
Summary: Transition metal dichalcogenides (TMDs) are promising candidates for the semiconductor industry due to their superior electrical properties. This study demonstrates the XeF2-mediated surface oxidation of 2H-MoTe2 to form a thin and uniform oxidized layer, which helps reduce contact resistance and improve field-effect hole mobility. The work provides a straightforward and effective method for 2D electronics.
NANOSCALE ADVANCES
(2022)
Article
Chemistry, Multidisciplinary
Sang Eun Yoon, Bomi Kim, So Yeon Chun, Sang Yeon Lee, Dohyeon Jeon, Minju Kim, Solin Lee, Bo Eun Seo, Kang Suh Choi, Felix Sunjoo Kim, Taekyeong Kim, Hyungtak Seo, Kyungwon Kwak, Jong H. Kim, BongSoo Kim
Summary: The study investigated the impact of molecular weight of conjugated polymers (CPs) on doping efficiency, electrical conductivity, and thermoelectric properties. Findings indicated that high molecular weight CPs tend to have higher carrier mobility and potential for maximal power generation.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Mohit Kumar, Unjeong Kim, WangGon Lee, Hyungtak Seo
Summary: This study presents a novel ReTFT memory that achieves high-speed and programmable multilevel storage, providing a solution for hardware implementation of in-memory computing. Additionally, various signal memory-processing operations are explored, offering potential applications in neuromorphic hardware.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Ranveer Singh, Hyunwoo Kang, Heechul Shin, Ji-Yong Park, Hyungtak Seo
Summary: The study investigated the 2DEG phenomenon at the interface of an amorphous-Al2O3-In2O3-amorphous-Al2O3 (AIA) heterostructure on a flexible substrate, showing promising opportunities for flexible oxide electronics. The AIA device exhibited a high stability with outstanding performance, and maintained good flexibility even after bending tests.
APPLIED SURFACE SCIENCE
(2022)
Article
Engineering, Environmental
Ji Min Han, Sang Eun Yoon, Ku Hyun Jung, Onyu Bae, Donguk Kim, Unjeong Kim, Hyungtak Seo, Felix Sunjoo Kim, Ki Chul Kim, Jong H. Kim, Bong-Gi Kim
Summary: This study synthesized a new conjugated polymer with efficient doping using both electron acceptor and Lewis acid type dopants, achieving high electrical conductivities. The interaction between the electron-donating atoms in the doped polymer and the dopants influenced the conductive properties and stability.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Shankara S. Kalanur, Hyungtak Seo
Summary: The influence of Nb doping on the photoelectrochemical water splitting activity of BiVO4 photoanode is explored. Experimental and theoretical studies show that Nb doping enhances the photocurrent density, charge separation efficiency, and charge transfer capability of BiVO4, leading to efficient H-2/O-2 evolution.
JOURNAL OF CATALYSIS
(2022)
Article
Materials Science, Multidisciplinary
Mohit Kumar, Ji-Yong Park, Hyungtak Seo
Summary: This study demonstrates an enhancement in the self-power UV photoresponse of the silver nanowires/TiO2 Schottky photodetector by utilizing the flexoelectric phenomenon. The device shows measurable photocurrent under low-intensity UV illumination by integrating the photovoltaic and flexo-phototronic effects, resulting in improved rise/fall times and remarkable responsivity and detectivity under self-biased conditions. Microscopic evidence of the flexoelectric effect modulated photoresponse is provided by photoconductive atomic force microscopy measurements.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Materials Science, Ceramics
Heecheol Shin, Hyobin Choi, Jaeseong Lim, Wanggon Lee, Kumar Mohit, Younsoo Kim, Hyung-Suk Jung, Hanjin Lim, Hyungtak Seo
Summary: The shrinkage and leakage current suppression of MIM capacitors are crucial for maintaining desired charge storage and retention levels in DRAM. This study uses ARXPS, SE, and temperature dependent I-V analysis to analyze a ZrO2-based dielectric film and its interface with a TiO2/Al2O3 buffer layer, demonstrating the importance of the buffer layer in controlling leakage current.
JOURNAL OF ASIAN CERAMIC SOCIETIES
(2022)
Article
Chemistry, Multidisciplinary
Shankara S. Kalanur, Young Jae Lee, Hyungtak Seo
Summary: In this study, a multijunction strategy with stoichiometrically engineered hole extraction layer and efficient, non-toxic MoOx catalyst layer sandwiched in Cu2O photocathode was proposed for enhanced charge separation and stable H2 production. The optimized multijunction system achieved high photocurrent and significant anodic shift in noble metal-free Cu2O photocathodes.
MATERIALS TODAY CHEMISTRY
(2022)
Article
Engineering, Electrical & Electronic
Mohit Kumar, Hyungtak Seo
Summary: This study presents a solid-state copper oxide-based device capable of adjustable optical transmittance through fine-tuning electric pulses. The device demonstrates nonvolatile multilevel memory and its working mechanism is explained by the change in stoichiometry of copper oxide induced by oxygen vacancy migration. This research offers a new avenue for the development of reconfigurable thin-film optical devices.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
