Article
Chemistry, Multidisciplinary
Weidong Song, Jiaxin Chen, Ziliang Li, Xiaosheng Fang
Summary: A self-powered, high-performance Ti3C2Tx MXene/GaN van der Waals heterojunction-based ultraviolet photodiode with outstanding quantum efficiency and rapid response speed is reported, showing remarkable photovoltaic behavior and power conversion efficiency.
ADVANCED MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
N. Wang, X. Pan, P. Wang, Y. Wang, H. He, Y. -j. Zeng, L. Zhang, Y. Li, F. Wang, B. Lu, J. Huang, Z. Ye
Summary: This study provides clear evidence that epitaxy on mica is not always of the van der Waals type, but a new epitaxy mode. We have successfully obtained high-quality ZnO epitaxial films with excellent crystal quality and optical properties on fluorphlogopite mica substrates. This compliant substrate epitaxy mechanism offers a low-cost reusable-substrate method for the production of high-quality functional films and flexible devices.
MATERIALS TODAY NANO
(2022)
Article
Materials Science, Multidisciplinary
Naveen Kumar, Muhammad Kumail, Junghyun Lee, Hyeong Gi Park, Joondong Kim
Summary: In this study, a self-powered transparent photodetector consisting of a vdW semiconductor (SnS) and a wide-bandgap oxide (Ga2O3) thin film was successfully fabricated. The device is highly transparent with an average visible transmittance of 45%. Under illumination, the self-biased transparent photodetector exhibits photovoltaic behavior, with a significant open circuit voltage of 496 mV and a considerably high short-circuit current density of 1.7 mA/cm^2. The device shows a significant photoresponse from UV (340 nm) to NIR (850 nm) illumination, with a remarkable responsivity of 210.4 mA/W and the fastest response time of approximately 8 ms, making it a self-operated broadband transparent photodetector.
MATERIALS RESEARCH BULLETIN
(2023)
Article
Chemistry, Physical
Aadil Waseem, Muhammad Ali Johar, Mostafa Afifi Hassan, Indrajit Bagal, Jun-Seok Ha, June Key Lee, Sang-Wan Ryu
Summary: Flexible and stable piezoelectric energy harvesters were successfully fabricated using polydimethylsiloxane-embedded m-axis GaN/Al2O3 core-shell nanowires transferred to indium-deposited flexible substrates. Optimizing the piezoelectric performance by controlling the Al2O3 shell thickness showed that a 6 nm thickness exhibited the maximum performance, with performance decreasing when the thickness was increased or decreased. The PEHs were effective in harvesting mechanical energy, even from static strain, and also demonstrated energy supply capabilities for operating a light emitting diode.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Peter Sutter, Juan-Carlos Idrobo, Eli Sutter
Summary: This study reports the realization of tunable twist in germanium(II) sulfide van der Waals nanowires, and presents a local spectroscopic method for detecting twist effects.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Y. -W. Chang, W. -C. Yang, W. -R. Lo, Z. -X. Lo, C. -H. Ma, Y. -H. Chu, Y. -C. Chou
Summary: A flexible GaN thin film was successfully obtained on mica through van der Waals epitaxy, reducing interfacial stress caused by thermal expansion coefficient mismatches. The optimized two-step growing process allowed the direct formation of low-stressed GaN thin film on mica, with transmittance controlled by surface roughness and growth temperature.
MATERIALS TODAY CHEMISTRY
(2022)
Article
Materials Science, Multidisciplinary
Wenliang Zhang, Qinghua Zhao, Carmen Munuera, Martin Lee, Eduardo Flores, Joao E. F. Rodrigues, Jose R. Ares, Carlos Sanchez, Javier Gainza, Herre S. J. van der Zant, Jose A. Alonso, Isabel J. Ferrer, Tao Wang, Riccardo Frisenda, Andres Castellanos-Gomez
Summary: The use of paper as a substrate for van der Waals (vdW) materials-based devices offers a promising alternative to silicon substrates in applications requiring low-cost electronic components. By fabricating films of various vdW materials on paper, it has been demonstrated that this technique shows great potential for producing electronic devices with high optical quality and exceptionally low electrical resistivity.
APPLIED MATERIALS TODAY
(2021)
Article
Chemistry, Physical
Yushuang Fu, Xinlin Liu, Cailing Liu, Yiguo Xu, Ayesha Khan Tareen, Karim Khan, Swelm Wageh, Omar A. Al-Hartomy, Abdullah G. Al-Sehemi, Han Zhang, Ye Zhang
Summary: In this study, a mixed-dimensional heterojunction of 0D Bismuth nanoparticles (Bi NPs) coated 2D Borophene (B@Bi) was prepared by a hydrothermal method. The resulting B@Bi-based photodetector (PD) exhibited enhanced self-powered photodetection properties, fast response and recovery speed, and repeatable ON/OFF switch signals after 30 days. This work provides an opportunity for fabricating high-performance mixed-dimensional B@Bi-based PDs with good long-term stability.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Huiming Shang, Feng Gao, Mingjin Dai, YunXia Hu, Shuai Wang, Bo Xu, Peng Wang, Bo Gao, Jia Zhang, PingAn Hu
Summary: A self-powered photodetector with light-induced electric field enhancement based on a 2D InSe/WSe2/SnS2 van der Waals heterojunction is designed, which achieves high responsivity and fast response speed by utilizing the light-induced electric field.
Article
Materials Science, Multidisciplinary
Gulsum Ersu, Carmen Munuera, Federico J. Mompean, Daniel Vaquero, Jorge Quereda, Joao Elias F. S. Rodrigues, Jose A. Alonso, Eduardo Flores, Jose R. Ares, Isabel J. Ferrer, Abdullah M. Al-Enizi, Ayman Nafady, Sruthi Kuriakose, Joshua O. Island, Andres Castellanos-Gomez
Summary: We have developed a method to fabricate thermoelectric devices on office paper substrates using handcrafting techniques. The devices consist of thin films of WS2, Te, and BP (P-type semiconductors) and TiS3 and TiS2 (N-type semiconductors) deposited by rubbing these materials' powders onto the paper. The semiconducting films exhibit high Seebeck coefficients, reaching (+1.32 +/- 0.27) mV K-1 for WS2 and (-0.82 +/- 0.15) mV K-1 for TiS3. Peltier elements were also constructed by connecting the P- and N-type films with graphite electrodes, achieving a thermopower value of up to 6.11 mV K-1 when the Peltier element had three junctions. This work demonstrates the potential application of semiconducting van der Waals materials in thermoelectric power generation and low-cost disposable electronic devices.
ENERGY & ENVIRONMENTAL MATERIALS
(2023)
Review
Chemistry, Multidisciplinary
Xiangdong Guo, Wei Lyu, Tinghan Chen, Yang Luo, Chenchen Wu, Bei Yang, Zhipei Sun, F. Javier Garcia de Abajo, Xiaoxia Yang, Qing Dai
Summary: 2D monolayers can be vertically stacked in van der Waals heterostructures to support a wide range of confined polaritons. This offers advantages in terms of controlling the constituent layers, stacking sequence, and twist angles. These heterostructures have extended the performance and functions of polaritons, and potential applications include nanophotonic integrated circuits.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Jinping Chen, Zhen Zhang, Yi Ma, Jiying Feng, Xiaoyu Xie, Xiaoxuan Wang, Aoqun Jian, Yuanzheng Li, Zhuxin Li, Heng Guo, Yizhi Zhu, Qiannan Cui, Zengliang Shi, Chunxiang Xu
Summary: A WS2/InSe van der Waals heterostructure (vdWH) photodiode was fabricated by stacking InSe and WS2 flakes using an all-dry transfer method. The heterostructure exhibited excellent photovoltaic behavior with a large open voltage, short-circuit current, fast response time, high light on/off ratio, high responsivity, and broadband photoresponse. This study provides a strategy for developing high-performance self-powered broadband photodetectors based on 2D materials.
Article
Chemistry, Physical
Jinping Chen, Zhen Zhang, Yi Ma, Jiying Feng, Xiaoyu Xie, Xiaoxuan Wang, Aoqun Jian, Yuanzheng Li, Zhuxin Li, Heng Guo, Yizhi Zhu, Qiannan Cui, Zengliang Shi, Chunxiang Xu
Summary: This study presents a WS2/InSe vdWH photodiode based on 2D materials, which exhibits excellent photovoltaic behavior and broadband photoresponse due to the precise stacking and energy-band alignment.
Article
Nanoscience & Nanotechnology
Xuran Zhang, Mingjin Dai, Wenjie Deng, Yongzhe Zhang, Qi Jie Wang
Summary: A PdSe2 photodetector with asymmetric van der Waals contacts is reported, achieving a high responsivity, fast rise/decay times, and a high detectivity in the visible-near infrared range. The device also shows linear polarization-sensitive response and outstanding polarization imaging capabilities. This PdSe2-based photodetector has great potential for high-performance applications without external bias.
Article
Multidisciplinary Sciences
A. J. Sternbach, S. H. Chae, S. Latini, A. A. Rikhter, Y. Shao, B. Li, D. Rhodes, B. Kim, P. J. Schuck, X. Xu, X-Y Zhu, R. D. Averitt, J. Hone, M. M. Fogler, A. Rubio, D. N. Basov
Summary: Layered crystals, such as tungsten diselenide, can exhibit unconventional optical properties that allow for the propagation of subdiffractional waveguide modes with hyperbolic dispersion. This study demonstrates optically induced hyperbolicity in WSe2 and explores the role of quantum transitions of excitons in the observed polaritonic response.
Article
Chemistry, Multidisciplinary
Aadil Waseem, Muhammad Ali Johar, Mostafa Afifi Hassan, Indrajit Bagal, Ameer Abdullah, Jun-Seok Ha, June Key Lee, Sang-Wan Ryu
Summary: The crystallographic orientation control of GaN nanowires was achieved by varying the indium composition in the Ga-Au alloy catalyst, with the alloy droplet size determining the density of the nanowires. Increasing the In composition inside the alloy catalyst shifted the crystallographic orientation of the GaN nanowires from m- to c-axis.
Article
Materials Science, Multidisciplinary
Ameer Abdullah, Muhammad Ali Johar, Aadil Waseem, Indrajit Bagal, Mostafa Afifi Hassan, June Key Lee, Sang-Wan Ryu
Summary: In this study, a noble metal/semiconductor composite photoanode was synthesized by depositing Au NPs on gallium nitride (GaN), resulting in a significant enhancement in photocurrent density. Additionally, improvements in STH conversion efficiency were achieved through efficient light harvesting and effective extraction of hot electrons and charge carrier collection.
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2022)
Article
Chemistry, Physical
Ameer Abdullah, Aadil Waseem, Indrajit V. Bagal, Muhammad Ali Johar, Mandar A. Kulkarni, June Key Lee, Sang-Wan Ryu
Summary: The efficient fabrication of photoanodes provides a new approach to improve the PEC water splitting efficiency. Deposition of Au nanoparticles on GaN nanowires surface is an effective method to enhance performance.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Aadil Waseem, Indrajit Bagal, Ameer Abdullah, Mandar A. Kulkarni, Hamza Thaalbi, Jun-Seok Ha, June Key Lee, Sang-Wan Ryu
Summary: In this study, a high-performance, flexible, and highly stable piezoelectric nanogenerator was prepared by directly growing the Mg-doped semi-insulating GaN nanowires on a metal foil. The nanogenerator showed high output power density and was able to be tested and monitored under various conditions.
Article
Green & Sustainable Science & Technology
Pratik Mane, Indrajit Bagal, Hyojung Bae, Vishal Burungale, Chaewon Seong, Sang-Wan Ryu, Jun-Seok Ha
Summary: This study investigates the interface-engineered monoclinic bismuth vanadate photoanodes, which improve charge carrier transport and significantly enhance the performance of photoelectrochemical water splitting.
ADVANCED SUSTAINABLE SYSTEMS
(2022)
Article
Physics, Applied
J. Lee, Y. C. Chiu, M. A. Johar, C. Bayram
Summary: Cubic GaN epitaxy on large-area U-grooved silicon (100) dies is achieved by metalorganic chemical vapor deposition, exhibiting excellent structural and optical properties. Further improvement in internal quantum efficiency of cubic GaN can be achieved through selective etching.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Applied
Indrajit Bagal, Maheswari Arunachalam, Ameer Abdullah, Aadil Waseem, Mandar A. Kulkarni, Soon Hyung Kang, Sang-Wan Ryu
Summary: This study presents strategic improvements in the PEC water splitting performance of ZnO nanowires by nitrogen doping and the core-shell deposition of a NiOOH cocatalyst. Nitrogen doping enhances visible light absorption and suppresses the recombination of photogenerated carriers. NiOOH-deposited N-doped ZnO nanowire photoanodes show significantly improved photostability and photocurrent density.
JOURNAL OF ENERGY CHEMISTRY
(2022)
Article
Chemistry, Physical
Indrajit Bagal, Aadil Waseem, Ameer Abdullah, Mandar A. Kulkarni, Jun-Seok Ha, Sang-Wan Ryu
Summary: We report the sequential fabrication of a three-dimensional hierarchical structure of Al2O3-passivated-CdS-anchored high-quality ZnO nanowire (NW) for photoelectrochemical water splitting. The optimized CdS/Si-ZnO HNWs show significant enhancements in photoconversion efficiency and photocurrent density compared to bare Si-ZnO HNWs. Furthermore, the photostability and photocorrosion resistance are improved by passivating the CdS/ZnO-Si HNWs using ultrathin Al2O3. The hierarchical NW photoanodes synergistically improve photocurrent and photostability, allowing for facile integration of II-VI materials with Si for next-generation energy applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Review
Materials Science, Multidisciplinary
Aadil Waseem, Zhongjie Ren, Hsien-Chih Huang, Kristen Nguyen, Xihang Wu, Xiuling Li
Summary: This review discusses the recent progress in epitaxial growth of beta-Ga2O3 films and highlights challenges in obtaining high growth rate, low defects, and high carrier mobilities. Compared with other methods, MOCVD offers a wider growth window and precursor selection option. The choice of MOCVD precursors, nucleation, and adsorption/desorption/diffusion of adatoms on substrate surfaces can affect growth defects, background impurity incorporation, and carrier mobilities.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Ameer Abdullah, Aadil Waseem, Indrajit Bagal, Muhammad Ali Johar, Mandar A. Kulkarni, Hamza Thaalbi, Jun-Seok Ha, June Key Lee, Sang-Wan Ryu
Summary: In this study, we investigated the influence of changing the number of InGaN/GaN quantum well pairs, optical bandgap tuning, and plasmonic coupling of Au nanoparticles (NPs) with multiquantum wells (MQWs) in photoelectrochemical (PEC) water splitting. MQWs showed a 2-fold improvement in photocurrent density and ABPE% compared to reference GaN at zero bias. Tuning the optical band gap by varying the growth temperature of MQWs has also been shown to influence the performance of PEC water splitting. Au NP/MQWs significantly enhanced photocurrent density and stability, with 80% photocurrent retention after 13.9 hours.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Physical
Indrajit V. Bagal, Seongmoon Jun, Minho Choi, Ameer Abdullah, Aadil Waseem, Seonghun Ahn, Mandar A. Kulkarni, Yong-Hoon Cho, Sang-Wan Ryu
Summary: In this study, shape-modulated ZnO nanowires (NWs) were synthesized and their role in achieving competent photoelectrochemical water splitting (PEC-WS) performance was investigated. The carrier dynamics of smooth (s-) and beaded ZnO NW (b-ZnO NW) photoanodes were analyzed using time-resolved, temperature-controlled photoluminescence spectroscopy. The enhanced PEC-WS performance with b-ZnO NWs was attributed to reduced surface recombination states, improved crystallinity, and enhanced carrier lifetime.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Electrical & Electronic
Aadil Waseem, Ameer Abdullah, Indrajit Bagal, Jun-Seok Ha, June Key Lee, Sang-Wan Ryu
Summary: This study proposes SA and RA mechanoreceptors based on GaN nanowire arrays, which can mimic the tactile perception principles of human skin. The designed e-skin can simulate both static and dynamic pressure signals, and can quickly respond to various pressure stimuli, making it practical for applications.
NPJ FLEXIBLE ELECTRONICS
(2022)