Article
Chemistry, Multidisciplinary
Shaurya Arya, Yunrui Jiang, Byung Ku Jung, Yalun Tang, Tse Nga Ng, Soong Ju Oh, Kenji Nomura, Yu-Hwa Lo
Summary: In this study, a compact and easy-to-use model for colloidal quantum dot (CQD) devices is developed. By considering the properties of quantum dots, ligand binding, and the heterointerface between quantum dots and the electron transport layer, the model can accurately describe and optimize the performance of CQD devices.
Article
Chemistry, Physical
Zeping Li, Xiong Yu, Yunhao Zhu, Sisi Liu, Xiaoyan Wen, Haifei Lu, Cong Wang, Xiao Li, Ming-Yu Li, Yingping Yang
Summary: In this study, ZnO quantum dot (QD) / magnetron sputtered ZnO homojunction photodetectors with excellent performance were fabricated by systematically varying the thickness ratios between two ZnO layers. The balanced ratio resulted in extra adsorption-desorption sites from the ZnO QDs and accelerated carrier transportation from the highly crystallized magnetron sputtered ZnO layers. As a result, the fabricated ZnO homojunction photodetector showed significantly increased responsivity and external quantum efficiency, paving the way for ultra-sensitive UV photodetection.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Siqi Jia, Menglei Hu, Mi Gu, Jingrui Ma, Depeng Li, Guohong Xiang, Pai Liu, Kai Wang, Peyman Servati, Wei Kun Ge, Xiao Wei Sun
Summary: This study demonstrates that the modification of ZnO nanocrystals with thiol ligands can improve the performance of red-emitting QLEDs, achieving higher external quantum efficiency and longer lifetime. Furthermore, the study reveals the significant impact of ZnO surface defects and electronic properties on device performance, highlighting the importance of optimizing the ZnO-QD interface.
Article
Chemistry, Multidisciplinary
Zhiyuan Huang, Ji Hao, Jeffrey L. Blackburn, Matthew C. Beard
Summary: This research demonstrates control of pyroelectricity in nanocrystalline systems by constructing a system built from spherical PbS quantum dots that can self-assemble into close-packed arrays or disperse into a polymer, both exhibiting a pyroelectric response. The polarization of each quantum dot can be easily tuned by constructing different Janus-ligand shells.
Article
Chemistry, Multidisciplinary
Marissa S. Martinez, Michelle A. Nolen, Nicholas F. Pompetti, Lee J. Richter, Carrie A. Farberow, Justin C. Johnson, Matthew C. Beard
Summary: Controlling the binding of functional organic molecules on quantum dot surfaces is crucial for understanding the resulting organic-inorganic hybrid behavior. In this study, the binding of tetracenedicarboxylate ligands on PbS quantum dots was varied through solid-state ligand exchange. Different ligand concentrations led to different structures and properties, with low concentrations resulting in mixed ligand structures, intermediate concentrations resulting in ligand-ligand interactions through hydrogen bonding, and high concentrations resulting in complete ligand exchange.
Article
Chemistry, Analytical
Jun Ho Lee, Seung-Eun Baek, Hyun-Sook Lee, Dahl-Young Khang, Wooyoung Lee
Summary: Through experiments and analysis, researchers have successfully developed highly sensitive acetone sensors. Among the four different sensors, the NC(0.5 h)/Line sensor exhibited the best response capability, with a low detection limit as well.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Engineering, Electrical & Electronic
Jiakun An, Gaoyu Chen, Xia Zhu, Xin Lv, Jianchun Bao, Xiangxing Xu
Summary: In this study, ambipolar photodetectors based on heterojunctions of CsPbX3 quantum dots and ZnO nanocrystals were developed, and the transition between positive and negative photoconductivity was successfully controlled. The research is significant for understanding the unique properties of the material and its potential applications in functional photodetectors.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Engineering, Environmental
Kusum Sharma, Pankaj Raizada, Vasudha Hasija, Pardeep Singh, Archana Bajpai, Van-Huy Nguyen, S. Rangabhashiyam, Pawan Kumar, Ashok Kumar Nadda, Soo Young Kim, Rajender S. Varma, Thi Thanh Nhi Le, Quyet Van Le
Summary: Solar light-driven photocatalysis is an effective method for environmental remediation, utilizing zinc sulfide quantum dots with various advantages. Strategies such as doping and heterojunction formation have been explored to address the inherent deficiencies of ZnS QDs. Further research is needed to overcome unresolved challenges for the future development of ZnS QDs photocatalysts.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Article
Nanoscience & Nanotechnology
Jian-Fu Tang, Yi-Da Sie, Zong-Liang Tseng, Ja-Hon Lin, Lung-Chien Chen, Cheng-Liang Hsu
Summary: In this study, a photodetector and humidity sensor based on zinc oxide nanowires (ZnO NWs) with CsPbBr3 perovskite quantum dots (PQDs) were developed. The excellent optoelectronic properties of PQDs make them ideal for semiconductor sensors. The experimental results showed that the performance of PQD/ZnO NWs was superior to that of ZnO NWs, especially in terms of humidity response and photocurrent.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Chanho Jo, Jaehyun Kim, Jee Young Kwak, Sung Min Kwon, Joon Bee Park, Jeehoon Kim, Gyeong-Su Park, Myung-Gil Kim, Yong-Hoon Kim, Sung Kyu Park
Summary: Artificial photonic synapses have the potential to emulate the human visual cognitive system, but the challenge of color discrimination remains. This study proposes an artificial multispectral color recognition system using ratio-controllable mixed quantum dot (M-QD) photoabsorbers, enabling high-efficiency visible color recognition, and adjustable synaptic plasticity for chromatic control in artificial photonic synapses.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Zibo Li, Fanchen Yu, Xia Xu, Tonghui Wang, Jinbo Fei, Jingcheng Hao, Junbai Li
Summary: We demonstrate the realization of photozyme-catalyzed oxidative phosphorylation through the assembly of ATP synthase-reconstituted proteoliposome coatings on microcapsules. This is achieved through layer-by-layer deposition of semiconducting graphitic carbon nitride (g-C3N4) nanosheets and polyelectrolytes. The encapsulated g-C3N4 nanosheets act as the photozyme, accelerating the oxidation of glucose to yield protons under light illumination, establishing an outward transmembrane proton gradient to drive ATP synthesis. This artificial design enables higher energy conversion efficiency compared to conventional oxidative phosphorylation systems.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Energy & Fuels
Andrea Rubino, Laura Calio, Mauricio E. Calvo, Hernan Miguez
Summary: Efficient charge transport is achieved in a network of ligand-free perovskite quantum dots embedded in an insulating porous matrix, improving both yield and stability. Solar cells based on this design show a 9.3% efficiency, the highest reported for scaffold-supported PQD solar cells, and enhanced stability under solar illumination compared to bulk counterparts.
Article
Chemistry, Physical
Shuchen Shi, Wenhao Bai, Tongtong Xuan, Tianliang Zhou, Guoyan Dong, Rong-Jun Xie
Summary: In this study, water-based inks were used to inkjet print perovskite quantum dot/polymer color conversion films with high resolution, efficiency, and stability for green, blue, and red emission. The results suggest that the designed water-based inks are promising for in situ inkjet printing high-resolution and reliable PQD CCFs for mini/micro-LED displays.
Article
Chemistry, Physical
Yuljae Cho, Bo Hou, Paul Giraud, Sangyeon Pak, SeungNam Cha
Summary: Research has shown that modulating charge carrier transport at the heterojunction interface with ferroelectric materials can enhance the performance of photovoltaic devices, reduce charge recombination, and improve conversion efficiency. The coupling of the ferroelectric effect with solar cells provides an important platform for the development of solution-processable flat panel solar cell technology.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Engineering, Chemical
Zihang Peng, Minhua Ai, Songbo Wang, Dechao Kong, Chengxiang Shi, Ji-Jun Zou, Ruijie Gao, Lun Pan
Summary: The construction of p-n heterojunction using p-ZnO quantum dots decorated on oxygen-defective TiO2 nanorods promoted the charge separation and improved the photoelectrochemical performance.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Yixiong Lin, Mariana Avvacumova, Ruilin Zhao, Xihan Chen, Matthew C. Beard, Yong Yan
Summary: This study demonstrates the direct utilization of solar energy through triplet energy transfer (TET) in lead halide perovskite semiconductors for photocatalytic reactions. It shows successful photocatalytic 2 + 2 cycloaddition reactions using TET from lead halide perovskite nanocrystals (PNCs). The findings suggest a new energy conversion pathway for employing PNCs in photocatalytic organic synthesis through direct TET.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
So-Yul Kim, Tae-Geol Lee, Seon-Ae Hwangbo, Jong-Ryul Jeong
Summary: This study utilized focused ultrasound dispersion to fabricate TiO2 nanoparticles with controlled size, which improved their effectiveness in degrading methylene blue. Controlling the aggregated size and adjusting the concentration of TiO2 are crucial factors for water treatment technologies utilizing TiO2 photocatalysis.
Review
Chemistry, Physical
Taewan Kim, Daekwon Shin, Meeree Kim, Hyoin Kim, Eunhye Cho, Mahnmin Choi, Jugyeong Kim, Eunji Jang, Sohee Jeong
Summary: Colloidal quantum dots, particularly group III-V CQDs, are being extensively researched due to their tunable energy band properties. Despite successful implementation in specific areas, such as light downconversion optoelectronics, most state-of-the-art group III-V CQD-based devices still suffer from low efficiency compared to other CQD-based devices. Efforts are being made to address challenges specific to efficient group III-V CQD-based optoelectronics design and fabrication, with a focus on synthesis, surface modification, and effective carrier modulation.
ACS ENERGY LETTERS
(2022)
Review
Chemistry, Multidisciplinary
Meeree Kim, Mahnmin Choi, Sinil Choi, Sohee Jeong
Summary: Developing next-generation colloidal semiconductor nanocrystals with high-quality optoelectronic properties and precise processability relies on achieving complete mastery over the surface characteristics of nanocrystals. Recent progress has been made by combining well-defined surface models with quantitative surface reactions, enabling a better understanding and manipulation of nanocrystal surface chemistry. This research presents a compelling case for utilizing facet-specific chemistry as a platform for mechanistic investigation and morphology exploration, which can pave the way for developing high-quality and precisely designed nanocrystals for optoelectronic technologies.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Nanoscience & Nanotechnology
Chuanxiao Xiao, Yaxin Zhai, Zhaoning Song, Kang Wang, Changlei Wang, Chun-Sheng Jiang, Matthew C. Beard, Yanfa Yan, Mowafak Al-Jassim
Summary: By using Kelvin probe force microscopy and transient reflection spectroscopy techniques, we spatially resolved the variation in microscopic optoelectronic properties of perovskite hetero-junctions in metal-halide PSCs during operation and studied the light-soaking effect. The evolution of the junction was attributed to ion migration and self-poling induced by built-in voltage. The device performances were correlated with the changes in electrostatic potential distribution and interfacial carrier dynamics. Our results present a new route for studying the complex operation mechanism in PSCs.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Mahnmin Choi, Meeree Kim, Yeunhee Lee, Taewan Kim, Jun Hyung Kim, Daekwon Shin, Jeong Won Kim, Yong-Hyun Kim, Sohee Jeong
Summary: The tunable band edge position of nonconductive colloidal quantum dot films is investigated using photo-electron spectroscopy and density functional theory calculations. The results show that the energy levels of nonconducting CQD films can be controlled by partially replacing the surface-bound ligand, providing a method for efficient optoelectronic device design.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Ji-Hwan Seol, Jae-Hyeon An, Trinh Nguyen Thi, Duc Duong Viet, Byong-Guk Park, Phuoc Cao Van, Jong-Ryul Jeong
Summary: Traditional annealing process takes a long time, but our method can shorten the annealing time by more than eight-fold. Our method can successfully fabricate polycrystalline YIG films with similar phases and magnetic properties as those prepared by conventional methods. We also studied spin thermoelectric effects using a platinum layer to detect spin, and the results showed that our annealing process can be used to fabricate YIG films for spin thermoelectric applications.
Article
Multidisciplinary Sciences
Jeong-Mok Kim, Seok-Jong Kim, Min-Gu Kang, Jong-Guk Choi, Soogil Lee, Jaehyeon Park, Cao Van Phuoc, Kyoung-Whan Kim, Kab-Jin Kim, Jong-Ryul Jeong, Kyung-Jin Lee, Byong-Guk Park
Summary: The Spin Seebeck effect (SSE) refers to the generation of electric voltage perpendicular to a temperature gradient using a magnon current. SSE has the potential for efficient thermoelectric devices because of its transverse geometry which simplifies the device structure for utilizing waste heat. However, SSE has low conversion efficiency that needs improvement for widespread application. In this study, we demonstrate a substantial enhancement of SSE by oxidizing a ferromagnet in normal metal/ferromagnet/oxide structures. The enhancement is attributed to the reduced exchange interaction in the oxidized region, which increases the temperature difference between magnons in the ferromagnet and electrons in the normal metal, or the gradient of magnon chemical potential in the ferromagnet. This result provides a promising method for improving SSE efficiency and invigorating research on thermoelectric conversion.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Boyun Choi, Gun-Woo Park, Jong-Ryul Jeong, Nari Jeon
Summary: This study compares the properties of FeOx thin films deposited using thermal atomic layer deposition (ALD) and plasma-enhanced ALD (PEALD), and evaluates the advantages and disadvantages of using bis(N,N'-di-butylacetamidinato)iron(II) as an Fe precursor in FeOx ALD.
Editorial Material
Nanoscience & Nanotechnology
Jeanne Crassous, Matthew J. Fuchter, Danna E. Freedman, Nicholas A. Kotov, Jooho Moon, Matthew C. Beard, Sascha Feldmann
Summary: Solution-processable semiconductors based on small molecules, polymers or halide perovskites combine sustainable manufacturing with exceptional optoelectronic properties that can be chemically tailored to achieve flexible and highly efficient optoelectronic and photonic devices. A new exciting research direction is the study of the influence of chirality on light-matter interactions in these soft materials and its exploitation for the simultaneous control of charge, spin and light. In this Viewpoint, researchers working on different types of chiral semiconductors discuss the most interesting directions in this rapidly expanding field.
NATURE REVIEWS MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Sunghu Kim, Seongmin Park, Meeree Kim, Sohee Jeong
Summary: Single-crystalline indium phosphide (InP) tetrapods were synthesized and proved to be a useful platform for studying multiple exciton behaviors. ZnCl2 precursor was used to enhance the optical performance of InP tetrapods, but no distinct enhancement in photoluminescence was observed. However, further shell growth on InP-ZnCl2 successfully preserved tetrapodal geometry and showed higher photoluminescence than tetrapodal InP/ZnSe. The crystal structure of InP-ZnCl2 was retained even with various Zn feed ratios.
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
(2023)
Review
Physics, Applied
Min Young Yoon, Hee Jung Yeom, Jong-Ryul Jeong, Jung Hyung Kim, Hyo-Chang Lee
Summary: Plasma-assisted atomic layer etching (ALE) is a next-generation semiconductor manufacturing process that has gained attention due to the increasing demand for damage-free, precise process technology. The reactive gases used in ALE, such as C4F8 and C4F6, play a crucial role in protecting the sidewalls of high-aspect-ratio patterns. Among the plasma sources for ALE, inductively coupled plasma (ICP) is widely used for its controllable ion energy and electron density.
APPLIED SCIENCE AND CONVERGENCE TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Marissa S. Martinez, Michelle A. Nolen, Nicholas F. Pompetti, Lee J. Richter, Carrie A. Farberow, Justin C. Johnson, Matthew C. Beard
Summary: Controlling the binding of functional organic molecules on quantum dot surfaces is crucial for understanding the resulting organic-inorganic hybrid behavior. In this study, the binding of tetracenedicarboxylate ligands on PbS quantum dots was varied through solid-state ligand exchange. Different ligand concentrations led to different structures and properties, with low concentrations resulting in mixed ligand structures, intermediate concentrations resulting in ligand-ligand interactions through hydrogen bonding, and high concentrations resulting in complete ligand exchange.
Article
Chemistry, Physical
Chaeyeon Lim, Mahnmin Choi, Taewan Kim, Daekwon Shin, Jung Hoon Song, Sohee Jeong
Summary: The electrical properties of solar cells fabricated with bandgap-tuned lead sulfide (PbS) quantum dots (QDs) were analyzed in this study. It was found that reducing the thickness of the QD active layer is necessary for achieving high power conversion efficiency, mainly due to the increasing doping concentration of the QD film as the QD bandgap decreases. It is suggested that the electrical characteristics of QD photovoltaic devices should be taken into consideration when designing their structures in relation to the bandgap.
MATERIALS TODAY ENERGY
(2023)
Article
Chemistry, Physical
Jumi Park, Eunhye Cho, Kyoungwon Park, Sohee Jeong, Dongho Kim
Summary: This study investigates the influence of electrochemical doping on the optical properties of single-crystalline InP nanotetrapods. The photoluminescence (PL) intensity of these tetrapods undergoes significant changes depending on the nature of charge transfer during electrochemical doping. Electron transfer leads to a decrease in the PL intensity, while injection of additional holes results in a remarkable increase in PL intensity. The injected holes occupy surface hole trap states, enhancing surface passivation and thus improving PL intensity. These findings highlight the potential of InP nanotetrapods as a novel nanostructure for nanocrystal applications.
APPLIED SURFACE SCIENCE
(2023)
