Article
Chemistry, Multidisciplinary
Bin Liu, Shujie Wang, Shijia Feng, He Li, Lifei Yang, Tuo Wang, Jinlong Gong
Summary: This study presents a Si photoelectrode passivated by an amorphous Si layer with an ultra-long minority carrier diffusion length, enabling applications in photoelectrochemical water reduction and oxidation. The chemically passivated Si photoelectrode breaks the trade-off between carrier transport and surface passivation in conventional Si photoelectrodes, achieving high photocurrent and stability. A monolithic unbiased artificial leaf with efficient solar to hydrogen conversion efficiency is constructed using this technology.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Physical
Gihun Jung, Choongman Moon, Filipe Martinho, Yonghoon Jung, Jinwoo Chu, Hyewon Park, Alireza Hajijafarassar, Rasmus Nielsen, Jorgen Schou, Jeongyoung Park, Peter Christian Kjaergaard Vesborg, Ole Hansen, Yunseog Lee, Stela Canulescu, Byungha Shin
Summary: A photoelectrochemical water splitting device based on a dual-junction monolithic tandem cell with high performance was developed. The device achieved the highest photocurrent density and solar-to-hydrogen conversion efficiency among dual-junction monolithic photoelectrochemical cells, except for III-V materials. The use of TOPCon Si, TTO and SnO2 in the device contributed to its stability and high efficiency.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Reza Keshavarzi, Mahlasadat Mousavian, MirKazem Omrani, Valiollah Mirkhani, Niloufar Afzali, Camilo A. Mesa, Iraj Mohammadpoor-Baltork, Sixto Gimenez
Summary: The research focuses on developing heterostructured BiVO4/WO3 and TiO2/PANi photoanodes for efficient photoelectrochemical (PEC) water splitting. Through optical modeling of the PEC cell, the spectral activity and light harvesting efficiency are optimized. Tandem and parallel dual-photoelectrode configurations are implemented to improve the collection efficiency. The obtained photocurrents are 1.68 and 2.29 mA/cm(2) at 1.23 V vs RHE for the tandem and parallel configurations, respectively, demonstrating a 4-6-fold enhancement factor.
SURFACES AND INTERFACES
(2023)
Article
Energy & Fuels
Lipin Chen, Mahdi Alqahtani, Christophe Levallois, Antoine Letoublon, Julie Stervinou, Rozenn Piron, Soline Boyer-Richard, Jean-Marc Jancu, Tony Rohel, Rozenn Bernard, Yoan Leger, Nicolas Bertru, Jiang Wu, Ivan P. Parkin, Charles Cornet
Summary: The study focuses on determining the structural, electronic, and optical properties of the GaP1-xSbx/Si tandem materials for solar water splitting applications. By growing GaPSb crystalline layer on Si with different Sb contents, the direct bandgap of 1.7eV is achieved at 32% Sb content, enabling efficient sunlight absorption in combination with Si's 1.1 eV bandgap. Furthermore, the band alignment analysis suggests the potential application of GaPSb/Si association for both hydrogen and oxygen evolution reactions.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2021)
Article
Chemistry, Physical
Yinguo Zhou, Lei Zhang, Kai Zhou
Summary: In this study, a commercially available perylene dye, PTCDA, was introduced between the halide perovskite layer and the TiO2 layer to improve the photoelectrochemical properties of the CH3NH3PbI3/TiO2 film in aqueous solution. The addition of the perylene dye led to a doubling of the photocurrent value compared to the bare perovskite-based film in aqueous solution. First-principles calculations revealed stable adsorption of the dye molecule on the perovskite substrate and different interactions depending on the surface terminations of the perovskite, providing insights for dye-sensitized halide perovskite materials in optoelectronic applications.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Analytical
Jing Sun, Hemeiling Cai, Zhichang Ma, Junwei Di
Summary: In this study, a photoelectrochemical sensor for trace detection of Cu2+ was developed using an ITO electrode modified with BiVO4, a semiconductor material. The adsorption of Cu2+ on the surface of the ITO/BiVO4 electrode led to a doping effect, which inhibited the photogenerated electron complex and increased the photocurrent. Furthermore, the addition of EDTA to the system allowed for desorption of Cu2+ from the electrode surface, resulting in the photocurrent returning to its blank value and enabling electrode reuse.
Article
Materials Science, Ceramics
Nguyen Manh Hung, Vu Thi Bich, Nguyen Duc Quang, Nguyen Tien Hiep, Chuang Nguyen, Sutripto Majumder, Pham Tien Hung, Phung Dinh Hoat, Nguyen Van Hoang, Nguyen Minh Hieu, Tien Dai Nguyen
Summary: A three-dimensional hierarchical CuS-CdS@TiO2 multi-heterostructure with a CuS semiconductor, CdS branches and TiO2 nanorods was designed as a highly efficient photoanode for PEC water splitting. The enhanced PEC performance was attributed to the wide range of solar spectrum absorption in CdS branches, the efficient electron transfer pathway provided by TiO2 nanorods, and the improved separation of electron-hole on the surface of the photoanode facilitated by the p-n junction formed between CuS and CdS@TiO2 heterostructure.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Analytical
Ziling Zhang, Bo Peng, Xilian Ouyang, Xu Zhu, Li Chen, Xinya Fan, Zheping Zhou, Jiajia Wang, Lin Tang
Summary: Inspired by the power generation mechanism of photofuel cell, a sensitive chloramphenicol detection method was developed through the dual-photoelectrode photoelectrochemical aptasensor. The method utilized 3D graphite carbon nitride as the photoanode and porous metal organic framework and Cu2O as the photocathode, achieving high and stable photocurrent output. The oxidation-reduction reaction completed the power supply capability, while ensuring selectivity, stability, and repeatability.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Chemistry, Physical
Chi Wing Lee, Feng-Wu Lin, Po-Hsun Liao, Ming-Lun Lee, Jinn-Kong Sheu
Summary: The study employed nickel oxide decoration on a p-n junction GaN photoanode prepared using a thermally annealed nickel film on a p-GaN surface layer, leading to increased photocurrent density and reduced photocorrosion.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Xiaoran Zhang, Yanhong Lyu, Huaijuan Zhou, Jianyun Zheng, Aibin Huang, Jingjing Ding, Chao Xie, Roland De Marco, Nataliya Tsud, Viacheslav Kalinovych, San Ping Jiang, Liming Dai, Shuangyin Wang
Summary: A Si-based hierarchically-structured PdCu/TiO2/Si photocathode with trifluoroethanol as the proton source was reported for lithium-mediated photoelectrochemical nitrogen reduction reaction (PEC NRR), achieving a record high NH3 yield of 43.09 mu g cm(-2) h(-1) and an excellent faradaic efficiency of 46.15%. The PEC measurements coupled with operando characterization revealed that the PdCu/TiO2/Si photocathode under N-2 pressures facilitated the reduction of N-2 to form lithium nitride, which reacted with active protons to produce NH3. The Li-mediated PEC NRR process was further enhanced by introducing small amounts of O-2 or CO2 to accelerate the decomposition of Li3N.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Zhihe Wei, Yanhui Su, Weiyi Pan, Junxia Shen, Ronglei Fan, Wenjun Yang, Zhao Deng, Mingrong Shen, Yang Peng
Summary: Silicon semiconductor functionalized with graphene layer and catalyst immobilization improves the performance and stability of the photocathode. Altering the stacking configuration of the immobilized catalyst further enhances the electron transfer rate and the photoelectrochemical (PEC) performance. The graphene-coated Si cathode immobilized with catalyst demonstrates remarkable PEC CO2RR performance in neutral solution.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Calton J. Kong, Emily L. Warren, Ann L. Greenaway, Rajiv Ramanujam Prabhakar, Adele C. Tamboli, Joel W. Ager
Summary: Cascade photoelectrocatalysis involves coupling different CO2 reduction catalysts to different branches to enhance the selectivity of solar-driven CO2 reduction. Design principles include tuning photocurrents and photovoltages to facilitate the target reaction.
SUSTAINABLE ENERGY & FUELS
(2021)
Article
Chemistry, Multidisciplinary
Esther Edwardes Moore, Virgil Andrei, Ana Rita Oliveira, Ana Margarida Coito, Ines A. C. Pereira, Erwin Reisner
Summary: By tuning the electrolyte constituents and utilizing a hierarchically structured TiO2 scaffold, an integrated biophotoelectrochemical device with high photocurrent density and energy conversion efficiency has been developed.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Chengjin Li, Xiaoxia Zhou, Qingming Zhang, Yi Xue, Zhaoyu Kuang, Han Zhao, Chung-Yuan Mou, Hangrong Chen
Summary: By synthesizing a novel photocathode Sn/TiO2/Si, the light absorption performance and electron transfer efficiency can be improved, promoting efficient photoelectrochemical reduction of CO2 to produce liquid products, with great potential.
Article
Chemistry, Analytical
Ruifang Yuan, Xue Zhang, Xiaodong Xue, Rui Feng, Yanxia Zhao, Meng Sun, Liangguo Yan, Tao Yan, Qin Wei
Summary: A self-powered photoelectrochemical aptasensor was developed for sensitive detection of 17 beta-estradiol (E-2). The aptasensor exhibited admirable selectivity, high sensitivity, and a wide linear range, making it a promising tool for environmental endocrine disruptor detection.
Review
Physics, Applied
Zhe Zhuang, Daisuke Iida, Kazuhiro Ohkawa
Summary: InGaN-based LEDs are efficient light sources in the blue-green range, but their efficiency decreases when extending to the red region, posing a challenge for integrating red, green, and blue LEDs for full-color micro-LED displays. This review summarizes the recent progress in InGaN-based red LEDs of various chip sizes, including epitaxial structures, device fabrication, and optical performance.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2022)
Review
Engineering, Electrical & Electronic
Daisuke Iida, Kazuhiro Ohkawa
Summary: GaN-based light-emitting devices have the potential to achieve all visible emissions, and they play an important role in micro-LED displays. This review focuses on the development of III-nitride red LEDs and highlights key techniques, such as growth and doping.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Artem Shushanian, Daisuke Iida, Zhe Zhuang, Yu Han, Kazuhiro Ohkawa
Summary: In this study, we investigated the wet electrochemical etching of n-GaN films in oxalic acid. By observing microphotographs and analyzing product data, we revealed the electrochemical oxidation mechanism of n-GaN in oxalic acid and the formation of porous structures.
Article
Crystallography
Martin Velazquez-Rizo, Pavel Kirilenko, Daisuke Iida, Zhe Zhuang, Kazuhiro Ohkawa
Summary: In this study, GaN and NiO/GaN electrodes were characterized under alkaline conditions using impedance spectroscopy. It was found that NiO modification of the surface states of GaN suppressed the surface states capacitance. This suggests that the carriers involved in the photocorrosion of GaN in alkaline conditions originate from its surface states. Additionally, the epitaxial relationship between NiO particles deposited on GaN was characterized using transmission electron microscopy, revealing symmetry constraints of NiO{111}||GaN{0002} and NiO[220] ||GaN[112 over bar 0].
Article
Physics, Applied
Martin Velazquez-Rizo, Mohammed A. Najmi, Daisuke Iida, Pavel Kirilenko, Kazuhiro Ohkawa
Summary: The characteristics of a N-polar InGaN layer grown on a SAM substrate without a low-temperature buffer layer were reported, showing tensile strain and a stoichiometry of In0.13Ga0.87N. Microstructural observation of the InGaN/SAM interface revealed that it occurs between the O atoms of the O-Sc SAM surface and the (Ga,In) atoms of InGaN.
APPLIED PHYSICS EXPRESS
(2022)
Article
Physics, Applied
Pavel Kirilenko, Daisuke Iida, Zhe Zhuang, Kazuhiro Ohkawa
Summary: The effect of sidewall passivation by hydrogen plasma on the performance of InGaN green micro-LEDs was investigated. Hydrogen passivation deactivates the surface region of p-GaN around the device mesa perimeter, suppressing hole injection and reducing leakage current caused by material degradation. The hydrogen passivation was found to significantly improve device efficiency, reducing reverse leakage current and enhancing external quantum efficiency.
APPLIED PHYSICS EXPRESS
(2022)
Article
Physics, Applied
Xin Hou, Shao-Sheng Fan, Huan Xu, Daisuke Iida, Yue-Jun Liu, Yang Mei, Guo-En Weng, Shao-Qiang Chen, Bao-Ping Zhang, Kazuhiro Ohkawa
Summary: In this study, the characterization of red InGaN/GaN multiple-quantum-well (MQW) structures is presented. The optical properties of two MQW structures with different n-GaN underlayer thicknesses are studied. The results show that a thicker n-GaN layer is beneficial for obtaining higher In content, but it also leads to stronger In-content fluctuations and more defects. Red MQWs with higher In content exhibit more deep localized states. Therefore, improving the uniformity of In-content distribution and reducing nonradiative recombination centers are critical challenges for achieving high-efficiency red InGaN MQWs.
APPLIED PHYSICS LETTERS
(2022)
Article
Optics
Xin Hou, Tao Yang, Shao-Sheng Fan, Haun Xu, Daisuke Iida, Yue-Jun Liu, Yang Mei, Guo-En Weng, Shao-Qiang Chen, Bao-Ping Zhang, Kazuhiro Ohkawa
Summary: The realization of red-emitting InGaN quantum well (QW) is a hot issue in current nitride semiconductor research. Low-Indium-content pre-well layer has been proven to improve the crystal quality of red QWs, while achieving uniform composition distribution at higher In content in red QWs remains a challenge. This study investigates the optical properties of blue pre-QW and red QWs with different well widths and growth conditions, and provides insights into the stress evolution and In fluctuation in red QWs. It serves as a useful reference for the development of InGaN-based red emission materials and devices.
Article
Nanoscience & Nanotechnology
Pavel Kirilenko, Mohammed A. Najmi, Bei Ma, Artem Shushanian, Martin Velazquez-Rizo, Daisuke Iida, Kazuhiro Ohkawa
Summary: High-crystallinity InGaN layers were successfully grown on ScAlMgO4 (SAM) substrates by metalorganic vapor-phase epitaxy. Atomically flat SAM substrates were prepared by cleaving along the c-plane, and direct InGaN growth without any low-temperature buffer layer was utilized. The resulting InGaN layer exhibited a distinct hexagonal hillock morphology and remarkable crystalline quality. X-ray rocking curve measurements showed that the (000 (2) over bar) and (10-1-2) peaks full widths at half-maximum were as good as 384 and 481 arcsec, respectively. The calculated threading dislocations densities were as low as 2.9 x 10(8) and 1.6 x 10(9) cm(-2) in the case of screw-type and edge-type dislocations, respectively. (c) 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Article
Optics
Chien-Chung Lin, Yuh-Renn Wu, Hao-Chung Kuo, Matthew S. Wong, Steven P. Denbaars, Shuji Nakamura, Ayush Pandey, Zetian Mi, Pengfei Tian, Kazuhiro Ohkawa, Daisuke Iida, Tao Wang, Yuefei Cai, Jie Bai, Zhiyong Yang, Yizhou Qian, Shin-Tson Wu, Jung Han, Chen Chen, Zhaojun Liu, Byung-Ryool Hyun, Jae-Hyun Kim, Bongkyun Jang, Hyeon-Don Kim, Hak-Joo Lee, Ying-Tsang Liu, Yu-Hung Lai, Yun-Li Li, Wanqing Meng, Haoliang Shen, Bin Liu, Xinran Wang, Kai-ling Liang, Cheng-Jhih Luo, Yen-Hsiang Fang
Summary: Micro light-emitting diode (micro-LED) is expected to play a significant role in future smart displays, offering advantages in various applications. The article focuses on the current status, challenges, and potential advances in micro-LED technology, highlighting the importance of epitaxy innovation and quantum scale structures. Peripheral components and technologies, such as microchip transfer and repair, heterogeneous integration, and novel 2D materials, are also discussed. The potential of micro-LED displays in augmented reality (AR) and the efforts to address existing problems are emphasized.
JOURNAL OF PHYSICS-PHOTONICS
(2023)
Article
Chemistry, Multidisciplinary
Artem Shushanian, Daisuke Iida, Yu Han, Kazuhiro Ohkawa
Summary: In this study, the water-splitting process and its side reactions on GaN-based photoelectrodes decorated with NiOx, FeOx, and CoOx nanoparticles were investigated. Physicochemical analyses of liquid and vapor phases were performed after the experiments in 1 M NaOH under ambient conditions. The results showed that the water-splitting process with GaN-based photoelectrodes produced hydrogen gas and hydrogen peroxide. Surface modifications of GaN structures increased the device performance and restricted the GaN electrocorrosion. The hydrogen generation efficiencies were obtained as ηH2(bare GaN) = 1.23%, ηH2(NiOx/GaN) = 4.31%, ηH2(FeOx/GaN) = 2.69%, and ηH2(CoOx/GaN) = 2.31%. The photoelectrode etching reaction moieties Qetch/Q were 11.5%, 0.21%, 0.26%, and 0.20% for bare GaN, NiOx/GaN, FeOx/GaN, and CoOx/GaN, respectively.
CHEMICAL COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Fu-He Hsiao, Tzu-Yi Lee, Wen-Chien Miao, Yi-Hua Pai, Daisuke Iida, Chun-Liang Lin, Fang-Chung Chen, Chi-Wai Chow, Chien-Chung Lin, Ray-Hua Horng, Jr-Hau He, Kazuhiro Ohkawa, Yu-Heng Hong, Chiao-Yun Chang, Hao-Chung Kuo
Summary: This study demonstrates the potential of InGaN-based red micro-LEDs with a single quantum well (SQW) structure for visible light communication applications. The SQW sample shows better crystal quality, with high-purity emission, narrower full width at half maximum, and higher internal quantum efficiency compared to InGaN red micro-LEDs with a double quantum wells (DQWs) structure. The SQW device exhibits higher maximum external quantum efficiency (5.95%) and experiences less blueshift with increasing current density compared to the DQWs device. Furthermore, the SQW device has a superior modulation bandwidth (424 MHz) and a data transmission rate of 800 Mbit/s at an injection current density of 2000 A/cm(2). These results indicate that InGaN-based SQW red micro-LEDs hold great promise for full-color micro-display and visible light communication applications.
Article
Chemistry, Multidisciplinary
Dhaifallah Almalawi, Sergei Lopatin, Paul R. Edwards, Bin Xin, Ram C. Subedi, Mohammed A. Najmi, Fatimah Alreshidi, Alessandro Genovese, Daisuke Iida, Nimer Wehbe, Boon S. Ooi, Kazuhiro Ohkawa, Robert W. Martin, Iman S. Roqan
Summary: In this study, a catalyst-free single-step growth strategy is explored to grow high-quality self-assembled single-crystal vertical GaN nanowires (NWs) on a wide range of substrates using pulsed laser deposition. The obtained NWs show single-crystalline nature and high optical quality. The growth is initiated by an in situ polycrystalline layer and then transforms into single-crystalline NW nucleation.
Article
Multidisciplinary Sciences
Mohammed A. Najmi, Pavel Kirilenko, Daisuke Iida, Kazuhiro Ohkawa
Summary: This study investigates the growth of N-polar InGaN layers on misoriented ScAlMgO4 substrates. It is found that N-polar InGaN with small-offset substrates exhibits hexagonal hillocks similar to those in N-polar GaN layers, while larger misorientation angles result in smoother surfaces of the InGaN layers. However, the crystalline quality of InGaN shows an opposite trend, with significantly improved quality observed at smaller misorientation angles. Unprecedented crystalline quality of N-polar InGaN is achieved using SAM substrates with a 0.5 degrees offset.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Artem Shushanian, Daisuke Iida, Yu Han, Kazuhiro Ohkawa
Summary: In this study, the electrochemical behavior of n-GaN anodic oxidation reaction was investigated in inorganic electrolytes within a voltage range of 5-20 V, as the pH value varied from 0 to 13. The results showed that this reaction proceeded via the formation of surface intermediates and formed branching current-oriented nanopores on the surface of n-GaN layer, depending on the reaction media.
NEW JOURNAL OF CHEMISTRY
(2022)