Article
Materials Science, Multidisciplinary
Yubin Kang, Jilong Tang, Fahad Azad, Xiaotian Zhu, Xue Chen, Xueying Chu, Dengkui Wang, Xuan Fang, Dan Fang, Fengyuan Lin, Kexue Li, Xiaohua Wang, Zhipeng Wei
Summary: Controlling the crystal structure of GaAs nanowires with Si doping and V/III ratio has been shown to influence the nucleation of ZB phase and result in different conductivity types in FET devices. These results provide a clear route towards nanoscale device fabrication.
Article
Materials Science, Multidisciplinary
Cuihua Zhao, Baishi Li, Xi Zhou, Jianhua Chen, Hongqun Tang
Summary: The study shows that the crystal structure of alpha-Fe2O3 changes after Ag and S doping, leading to a slight shift of the optical absorption peak towards shorter wavelengths. Additionally, optical absorption in the visible range is significantly enhanced after Ag and S doping.
Article
Chemistry, Multidisciplinary
Yali Sun, Pengfei Qiu, Wei Yu, Jianjun Li, Hongling Guo, Li Wu, Hao Luo, Rutao Meng, Yi Zhang, Shengzhong (Frank) Liu
Summary: By utilizing n-type Ag2ZnSnS4 to design the CZTSSe absorber for surface modification, Ag was found to play crucial roles in kesterite thin film devices, leading to improved performance of the solar cell with an efficiency of up to 12.55% and reducing the open-circuit voltage deficit to 0.306 V.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Xiaokang Geng, Tian Du, Chenhui Xu, Yingying Liu, Yunfeng Deng, Yanhou Geng
Summary: In this study, two conjugated polymers (CPs) were synthesized to obtain p-type and n-type conductive materials through selective doping. PTQDPP-2FT performed better in organic thermoelectric devices, with p-type and n-type power factors of 278.2 and 2.37 mu W m(-1) K-2, respectively. These are the best bipolar (p-type and n-type) performances achieved by selective doping of a single polymer.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Review
Engineering, Electrical & Electronic
Ruqi Yang, Fengzhi Wang, Jianguo Lu, Yangdan Lu, Bojing Lu, Siqin Li, Zhizhen Ye
Summary: ZnO is a significant semiconductor material widely used in various fields due to its direct band gap, large exciton binding energy, and easy growth of high-quality nanostructures. However, obtaining high-quality p-type ZnO has been a major challenge. In this review, we discuss various methods such as increasing acceptor concentration, shallowing acceptor energy levels, and reducing donor defects to obtain high-quality p-ZnO. We also summarize the applications of p-ZnO in LEDs, UV detectors, thin-film transistors, gas sensing, and bionic materials.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Jiaoyan He, Yuanbo Wen, Dongshuang Han, Peiyu Zeng, Peng Zheng, Liang Zheng, Weitao Su, Zhangting Wu, Yang Zhang
Summary: Controllable p- and n-type doping of tungsten diselenide (WSe2) and molybdenum ditelluride (MoTe2) via argon (Ar) plasma treatment is reported. The doping of TMDs was tuned by controlling Ar plasma treatment conditions, resulting in increased electron current and hole current.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Materials Science, Ceramics
X. Vendrell, E. L. Santos-Veiga, H. Beltran-Mir, E. Cordoncillo, L. Mestres
Summary: Heterovalent B-site MgO substitution in the Nd2Zr2O7-system has been investigated and its effects on the structure and electrical behavior of the materials were characterized. The study reveals that heterovalent dopants can significantly enhance the oxide-ion conductivity of pyrochlore-like materials.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Yucheng Xiong, Guoqing Zhou, Nien-Chu Lai, Xiaomeng Wang, Yi-Chun Lu, Oleg Prezhdo, Dongyan Xu
Summary: This research demonstrates switchable n-type and p-type electrical conduction in Bi2Se3 nanoribbons through a facile chemical approach, opening up new possibilities for the development of thermoelectric devices and offering significant implications in the fields of spintronics and quantum computing.
Article
Environmental Sciences
S. P. Keerthana, R. Yuvakkumar, G. Ravi, P. Kumar, Mohamed Soliman Elshikh, Hussein H. Alkhamis, Abdulwahed F. Alrefaei, Dhayalan Velauthapillai
Summary: The photocatalytic dye degradation of pure alpha-Fe2O3 and different concentrations of Co-doped alpha-Fe2O3 were studied, and the 4% Co-doped sample showed the most efficient dye degradation at 92%.
Article
Chemistry, Physical
Chunqing Ma, Bosung Kim, Dong-Ho Kang, Sang-Woo Kim, Nam-Gyu Park
Summary: A nonchemical charge transfer doping approach is used to continuously tune the work function of perovskite, leading to improved conductivity. Positive and negative applied voltages result in n- and p-type charge transfer doping, respectively, enhancing carrier mobility and density. This tunable work function offers insights into innovative exploitation of perovskite materials in optoelectronic devices.
ACS ENERGY LETTERS
(2021)
Article
Chemistry, Physical
Chongyong Yan, Jie Su, Yifei Wang, Zhenhua Lin, Jincheng Zhang, Jingjing Chang, Yue Hao
Summary: Fabricating p-type beta-Ga2O3 with shallow acceptor levels is crucial for devices based on beta-Ga2O3. The proposed (electron-poor metal, N) co-doping method effectively reduces acceptor levels and hinders the formation of vacancies, thereby limiting the formation of p-type beta-Ga2O3.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Yue-Xing Chen, Xiao-Lei Shi, Zhuang-Hao Zheng, Fu Li, Wei-Di Liu, Wen-Yi Chen, Xin-Ru Li, Guang-Xing Liang, Jing-Ting Luo, Ping Fan, Zhi-Gang Chen
Summary: This study introduces p-type two-dimensional WSe2 nanoinclusions into n-type polycrystalline SnSe for the formation of p-n junctions, resulting in enhanced thermoelectric performance through phonon scattering and Fermi level control.
MATERIALS TODAY PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
M. Rahman, M. Kamruzzaman, J. A. Zapien, R. Afrose, T. K. Anam, M. N. H. Liton, M. A. Helal, M. K. R. Khan
Summary: Elemental doping is an efficient strategy to modulate different properties of semiconductors, and this study investigates the conversion from n-type to p-type and band gap modulation of ZnO using both theoretical and experimental approaches. The results show that silver (Ag) and silver-lithium (Ag-Li) doping can create acceptor levels in ZnO, making them promising dopants for generating p-type ZnO. Significant changes in photoconductivity and optical properties are also observed. This study helps in understanding the doping mechanism in ZnO and provides insights for the fabrication of p-type ZnO for advanced electronic and opto-electronic applications.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Engineering, Environmental
Fan Li, Jie Jian, Shiyuan Wang, Ziying Zhang, Lichao Jia, Xiangjiu Guan, Yadong Xu, Hongqiang Wang
Summary: The laser embedding of p-n heterointerfaces is proposed as a method to improve carrier transfer and address carrier loss at the semiconductor-liquid junction of metal oxides, leading to high-performance photoelectrodes for solar hydrogen generation.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Nanoscience & Nanotechnology
Ashi Ikram, Mohammad Zulfequar
Summary: This study investigates the effect of incorporating graphene and Cu2ZnSnS4 (CZTS) quantum dots (QDs) into a hematite thin film for use in a photoelectrochemical cell. By decorating the CZTS QDs on a graphene-hematite composite using a simple chemical approach, the combined modification has produced significantly higher photocurrent compared to separate graphene or CZTS QDs modifications. The presence of CZTS QDs over the hematite-graphene composite enhances the absorption properties and creates a p-n junction heterostructure that aids charge carrier transportation.
Review
Chemistry, Multidisciplinary
Takeshi Morikawa, Shunsuke Sato, Keita Sekizawa, Tomiko M. Suzuki, Takeo Arai
Summary: This article introduces an artificial photosynthetic system for the recycling of CO2 using solar energy. By integrating hybrid photocatalysts and photoelectrodes, this system effectively catalyzes the reduction of CO2, storing solar energy and promoting circular economy.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Shunya Yoshino, Akihide Iwase, Yuichi Yamaguchi, Tomiko M. Suzuki, Takeshi Morikawa, Akihiko Kudo
Summary: In this study, we demonstrated the photocatalytic reduction of CO2 using water as an electron donor under visible light irradiation. The Z-scheme system using bare (CuGa)(0.5)ZnS2 photocatalyst and RGO-(CoOx/BiVO4) as an O2-evolving photocatalyst exhibited efficient CO production accompanied by H2 and O2 evolution. The addition of a basic salt enhanced the CO formation rate and selectivity. This Z-scheme system also showed activity for solar CO2 reduction using water as an electron donor. The bare (CuGa)(0.5)ZnS2 powder loaded on an FTO glass was used as a photocathode, resulting in the production of CO and H2 with high Faradaic efficiencies.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Kenji Kamada, Hiroko Okuwa, Taku Wakabayashi, Keita Sekizawa, Shunsuke Sato, Takeshi Morikawa, Jieun Jung, Susumu Saito
Summary: A novel mononuclear ruthenium complex was introduced as a self-photosensitized catalyst for the reduction of carbon dioxide. The preactivation of the catalyst significantly reduced the induction period, and the catalyst turnover numbers reached 307 and 489 for carbon monoxide and formic acid, respectively, over a reaction time of 144 h. The complex exhibited a long lifespan as a dual photosensitizer and reduction catalyst.
Article
Chemistry, Multidisciplinary
Naohiko Kato, Yasuhiko Takeda, Yasuaki Kawai, Natsumi Nojiri, Masahito Shiozawa, Shintaro Mizuno, Ken-ichi Yamanaka, Takeshi Morikawa, Tsuyoshi Hamaguchi
Summary: In this study, a large-scale EC reactor for CO2 reduction to formate powered by a single-crystalline silicon PV module was constructed, achieving a high solar-to-chemical energy conversion efficiency of 10.5%. The use of efficient catalysts and low-resistive materials for the reactor components resulted in a high operating current of 65 A at a low voltage of around 1.65 V. By effectively suppressing crossover reactions and utilizing nanoporous separators, a simple and scalable reactor configuration suitable for large-scale CO2 reduction was achieved.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Chemistry, Physical
Yasuhiko Takeda, Shunsuke Sato, Takeshi Morikawa
Summary: In this study, we applied hot-carrier extraction to particulate photocatalysts and found that the hot-carrier photocatalysts have higher solar-to-chemical energy conversion efficiencies for H-2 and CO production. However, efficient hot-carrier extraction requires a sufficiently large carrier density in the core, which can be achieved through concentrated solar illumination.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Inorganic & Nuclear
Taku Wakabayashi, Kenji Kamada, Keita Sekizawa, Shunsuke Sato, Takeshi Morikawa, Jieun Jung, Susumu Saito
Summary: This study reports the application of a new iron catalyst in photochemical CO2 reduction, successfully synthesizing CO and HCO2H, and achieving catalysis through electron transfer mediated by a photosensitizer.
Article
Physics, Applied
Yasuhiko Takeda, Ken-ichi Yamanaka, Takeshi Morikawa, Naohiko Kato
Summary: This study presents the design of monolithic devices that combine photovoltaic (PV) modules and electrochemical (EC) reactor modules for artificial photosynthetic hydrogen (H-2) and carbon monoxide (CO) production. By using a combination of voltage-matched tandem PV modules and series-connected EC reactors, the current mismatching issue in double-junction PV cells under solar spectrum variation is effectively solved, resulting in improved energy conversion efficiencies for H-2 and CO production.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Tomiko M. Suzuki, Shunya Yoshino, Keita Sekizawa, Yuichi Yamaguchi, Akihiko Kudo, Takeshi Morikawa
Summary: This study demonstrates a visible-light-driven Z-scheme photocatalytic CO2 reduction reaction to produce CO using two bare semiconductors in an aqueous dispersion. The results show high selectivity and productivity, suggesting the potential for achieving sustainable and highly active artificial photosynthetic systems.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Physics, Applied
Yasuhiko Takeda, Shunsuke Sato, Takeshi Morikawa
Summary: We investigated the application of hot-carrier extraction in solar cells and photocatalysts for artificial photosynthesis, and compared the differences between these two applications: hot-carrier solar cells (HC-SCs) and hot-carrier photocatalysts (HC-PCs) through detailed balance calculations. We found that the hot-carrier effect is less significant in the photocatalysts compared to the solar cells, due to the larger bandgaps required for generating high-energy carriers for the reactions. However, impact ionization and Auger recombination (IA) significantly improve the efficiency of HC-PCs by functioning as photon upconverters and narrowing the optimal bandgap, while also enhancing the spectral robustness.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Yasuhiko Takeda, Ken-ichi Yamanaka, Takeshi Morikawa, Naohiko Kato
Summary: We established guidelines for designing artificial photosynthetic devices that produce H-2 and CO. Our approach involved using a voltage-matched tandem solar cell module in combination with an electrochemical module. Tests showed that optimizing the series connection numbers is crucial to minimize voltage mismatch, particularly under slightly higher solar intensity and temperature conditions. Interestingly, the annual electricity production of the voltage-matched solar cell module coupled with a power conditioner was unaffected by optimization conditions or changes in the bandgaps of the solar cells.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Yasuhiko Takeda, Shintaro Mizuno, Ryuichi Iwata, Takeshi Morikawa, Naohiko Kato
Summary: Direct electrochemical reduction of dilute CO2 in a flue gas without capture and condensation processes can decrease energy consumption. However, it faces challenges of insufficient CO2 supply rate and preferential reduction of O2. To overcome these, a new concept called gas-fed liquid-covered electrodes (GFLCEs) is proposed, where a thin liquid cover layer allows high CO2 concentration while reducing O2 concentration. By utilizing GFLCEs with MEA additive, high Faradaic efficiencies of around 70% were achieved for formate production under direct feeding of a simulated flue gas.
JOURNAL OF CO2 UTILIZATION
(2023)
Article
Chemistry, Physical
Marcella Bonchio, Julien Bonin, Osamu Ishitani, Tong-Bu Lu, Takeshi Morikawa, Amanda J. Morris, Erwin Reisner, Debashrita Sarkar, Francesca M. Toma, Marc Robert
Summary: Visible-light-driven conversion of CO2 to fuels and valuable compounds has been highly active in recent years. However, these processes and catalytic systems are still in early stages of development, with fundamental mechanistic challenges needing to be addressed. Collaborative efforts are needed to explore various approaches and establish robust practices to advance our understanding of these necessary processes.
Article
Chemistry, Multidisciplinary
Tomiko M. Suzuki, Kengo Nagatsuka, Takamasa Nonaka, Yuichi Yamaguchi, Naonari Sakamoto, Takeshi Morikawa, Keita Sekizawa, Akihiko Kudo, Takeshi Morikawa
Summary: A water-soluble Co complex efficiently reduced CO2 to CO electrochemically in an aqueous medium without an organic solvent. The reaction showed almost 100% selectivity at -0.80 V vs. NHE with a low overpotential of 270 mV. The study discussed the possible mechanism of CO formation based on experiments and calculations.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Takahiro Ikeda, Tomiko M. Suzuki, Takeo Arai, Takeshi Morikawa
Summary: Traditionally, N-doped TiO2 has been considered unsuitable for the oxygen evolution reaction under visible light. However, by using Ni-modified beta-FeOOH nanorod cocatalysts, N 2p holes in the N-TiO2 photoanode can be utilized for the OER, resulting in a 13-fold increase in anodic photocurrent of N-TiO2 with 100% faradaic efficiency.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Yasuhiko Takeda, Tomiko M. Suzuki, Shunsuke Sato, Takeshi Morikawa
Summary: The article introduces the application of spectrum splitting in particulate photocatalytic reactors, discusses the feasibility and effects of multiple cells/compartments. Two reactor configurations are proposed, and through establishing a new model and calculating practical limits, it is shown that spectrum-splitting reactors achieve higher efficiency.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
