Article
Chemistry, Physical
Ana-Maria Craciun, Laurentiu Susu, Monica Baia
Summary: The intrinsic photoluminescence properties of gold nanorods coated with gelatin were studied using innovative fluorescence spectroscopy combined with fluorescence lifetime imaging microscopy. The study revealed interesting aspect ratio-dependent two-photon excited photoluminescence emission, with a lifetime of around 100 ps. The effect of laser excitation power and wavelength on the photoluminescence performance was evaluated, highlighting the potential application of gelatin-coated gold nanorods as contrast agents for label-free two-photon fluorescence imaging.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Chemistry, Multidisciplinary
Zong Yu Wu, Jie-Hao Zhuang, Yu-Tsung Lin, Yu-Hsun Chou, Pin Chieh Wu, Chung-Lin Wu, Peter Chen, Hsu-Cheng Hsu
Summary: The study investigated the thermal photoluminescence characteristics of CsSnBr3 microstructures and their PL quenching behavior at high temperature. The monotonic blue shifts in PL emission upon temperature increase suggest a band gap widening associated with an emphasis effect. The estimated activation energy of thermally assisted nonradiative recombination for CsSnBr3 microsquares and micropyramids is higher than CsPbBr3, indicating better thermal stability.
Article
Optics
I. D. Laktaev, B. M. Saidzhonov, R. B. Vasiliev, A. M. Smirnov, O. V. Butov
Summary: The photoluminescence features of a light-hole - electron exciton transition in CdSe/CdS nanoplatelets colloidal solution under resonant two-photon excitation were investigated. The powerlaw dependence of the photoluminescence intensity on the excitation laser femtosecond pulses intensity was discovered to be related to biexciton radiation. In addition, the conditions for the photoluminescence growth and quenching were determined based on the concentration and pump intensity.
JOURNAL OF LUMINESCENCE
(2022)
Article
Biochemistry & Molecular Biology
Anna Pniakowska, Joanna Olesiak-Banska
Summary: This work demonstrates the two-photon excited luminescence of single gold nanoclusters in the near infrared region and observes a 25-fold enhancement of emission. It is an important step towards the application of combined nanoparticles in multiphoton imaging and biosensing.
Article
Materials Science, Multidisciplinary
Dongwan Kim, Jae-Young Leem
Summary: In this study, high-quality In-doped ZnO nanorods (IZO NRs) were fabricated using the vapor-confined face-to-face annealing (VC-FTFA) method. The oxidation of chloride vapor generated during the annealing process was found to significantly affect the photoresponse properties. The regrowth mechanism for the IZO NRs involves the vapor-solid oxidation and subsequent condensation of Zn and In vapors. The regrown IZO NRs exhibited improved crystallinity and higher near-band edge emission intensity compared to hydrothermally grown ZnO NRs. An UV photodetector based on the regrown IZO NRs demonstrated enhanced photoresponse rate, stability, and reproducibility. This study presents a facile approach for the fabrication of fast-response UV photodetectors with significant photosensitivity and photocurrent stability.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Chemistry, Physical
Xiaonan Xi, Yuanyuan Li, Tianyuan Liang, Huaxin Wu, Ruonan Miao, Chao Gu, Jiyang Fan
Summary: The study presents the fabrication of epitaxial pyramidal ZnO-Au HNCs and investigates their unique photophysical properties. Strong coupling between ZnO NC green defect-related recombination and localized surface plasmon resonance of Au nanospheres leads to nearly complete quenching of green defect luminescence in the ZnO NCs.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Shravan K. Appani, Mohammad Monish, R. Nandi, D. Singh, S. S. Major
Summary: High-quality epitaxial ZnO thin films and nanorods were grown on c-sapphire substrate by reactive sputtering. The morphology transformed from columnar films to vertically aligned nanorods with increase in substrate temperature. The crystalline and epitaxial quality improved, and the edge dislocation density decreased. The biaxial stress changed from compressive to tensile for nanorods at higher temperatures, leading to enhanced photoluminescence.
Article
Materials Science, Multidisciplinary
Tomoaki Terasako, Kohdai Hamamoto, Masakazu Yagi, Yutaka Furubayashi, Tetsuya Yamamoto
Summary: Zinc oxide nanorods were grown on various doped seed layers by chemical bath deposition, resulting in different alignment patterns and dimensions. The growth time significantly affected the morphology and density of the nanorods, with an increase leading to changes in width, length, and density. Furthermore, varying strains and photoluminescence emissions were observed depending on the seed layer used for growth.
Article
Engineering, Electrical & Electronic
Carlos A. Rodriguez-Castaneda, Paola M. Moreno-Romero, D. Mateus Torres-Herrera, Candy A. Enriquez-Alamares, Hugo J. Cortina-Marrero, I. Montoya de los Santos, Maykel Courel, F. J. Sanchez-Rodriguez, Hailin Hu, L. Hechavarria-Difur
Summary: This study investigates the impact of ZnO on the performance of perovskite solar cells, revealing that the addition of a PC71BM layer can enhance efficiency but leads to decreased stability under high humidity conditions.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Chemistry, Multidisciplinary
Hai-Quan Liu, Cheng-Bao Yao, Yu Cai, Hai-Tao Yin
Summary: The Ag-ZnO sandwich structure with columnar, cylinder and scallops-shaped has been successfully synthesized. X-ray diffraction analysis confirmed the presence of hexagonal wurtzite ZnO and face-centered cubic Ag in the structure. The growth mechanism was explained by vapor-liquid-solid mechanism. The photoluminescence spectrum showed an enhanced visible emission intensity, indicating the injection effect of Ag core. The excellent photodegradation activity of the Ag-ZnO sandwich structure is attributed to the synergistic effects of large surface area, unique ohmic contact, and electron transfer in the bandgap structure.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2022)
Article
Materials Science, Multidisciplinary
Tatsuya Honbu, Daisuke Takeuchi, Kimiyoshi Ichikawa, Shinya Ohmagari, Tokuyuki Teraji, Masahiko Ogura, Hiromitsu Kato, Toshiharu Makino, Ichiro Shoji
Summary: The density of dislocations in the intrinsic layer of a pin diamond diode was estimated using 2PPL imaging, showing no impact from the generation and diffusion of free carriers. This is important for assessing diamond device performance as it allows for avoiding the influence of free carrier propagation on the adjacent layer.
DIAMOND AND RELATED MATERIALS
(2021)
Article
Optics
Sandro Heuke, Carla Silva Martins, Remi Andre, Loic Legoff, Herve Rigneault
Summary: Two-photon excited fluorescence (2PEF) microscopy is a popular nonlinear imaging method for biomedical samples. It uses multiple detectors and spectral filter sets to discriminate different fluorophores based on their emission behavior. However, 2PEF suffers from the loss of fluorescence photons outside the filter transmission range and may fail to discriminate fluorophores with similar emission profiles. Here, we propose an alternative 2PEF method that discriminates fluorophores based on their excitation spectra.
Article
Chemistry, Inorganic & Nuclear
Po-Hsuan Hsiao, Ta-Cheng Wei, Chia-Yun Chen
Summary: The study achieved a dual enhancement in photodetection performance and environmental stability by applying Cu2+-doped ZnS as protective coatings on ZnO nanorods, demonstrating a significant improvement in detectivity under light illuminations. Additionally, the designed photodetector showed good environmental stability during long-term utilization.
INORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Hongqian Cao, Yanfei Qi, Xibao Gao, Zi Jin Wei, Jiarui Xia, Lei Wang, Hao Wang, Yang Yang, Junbai Li
Summary: The novel peptide nanodrug, consisting of three functional motifs - bis(pyrene), FFVLK and CREKA, is used as a two-photon excited photosensitizer for precise photodynamic therapy (PDT), showing excellent two-photon imaging ability, tumor target effect and high reactive oxygen species productivity to improve treatment precision and efficiency in PDT.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
M. M. Zeidan, S. Abedrabbo
Summary: Modified Am-241-Be neutron beams can change the optical properties of zinc oxide (ZnO) photoluminescence (PL) spectra by transmuting zinc (Zn) into gallium (Ga) after irradiation. This study investigates the time required by slow neutron irradiation to register the transmutation of Zn into Ga. Two series of samples from different suppliers (TEW Tokyo Denpa Co. Ltd., Tokyo, Japan and MTI corporation, China) are irradiated for 6, 12, 18, and 24 days on the Zn-polar face of each sample to determine the relationship between irradiation intensity and transmutation.
Article
Chemistry, Physical
Xiangwei Qu, Jingrui Ma, Pai Liu, Kai Wang, Xiao Wei Sun
Summary: This work investigates the voltage sweep behavior of quantum dot light-emitting diodes (QLEDs). It is found that red QLEDs with ZnMgO electron transport layer (ETL) experience a drop in efficiency under consecutive voltage sweeps, while devices with ZnO ETL show an increase in efficiency. The analysis reveals that the efficiency drop in ZnMgO devices is related to hole leakage mediated by trap states on ZnMgO nanoparticles. Furthermore, the hole leakage also causes rapid lifetime degradation of ZnMgO devices.
Article
Optics
Huayu Wei, Qi Wei, Fan Fang, Guohong Xiang, Bingyi Tong, Chenlin Wang, Baoqing Sun, Xian Zhao, Mingjie Li, Xiao Wei Sun, Yuan Gao
Summary: This study developed environmentally friendly CQDs with high emission efficiency, achieving optical gain and lasing in the blue spectral region. The alloyed CQDs showed lower threshold and fluence, suggesting potential applications.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Physical
Qingqian Wang, Hongmei Zhu, Wei Chen, Junjie Hao, Zhaojin Wang, Jun Tang, Yingguo Yang, Xiao Wei Sun, Dan Wu, Kai Wang
Summary: This study proposes an effective strategy to achieve high CPL activity in quantum dots by introducing 2D chiral perovskite as a chiral source, providing spin polarized carriers through the CISS effect. The as-synthesized QDs/CP composites exhibit dissymmetry factors (g(lum)) up to 9.06 x 10(-3). These findings provide a useful method to achieve CPL in QDs/2D chiral perovskite heterojunctions, which could be promising in spin-optoelectronics application.
Article
Chemistry, Multidisciplinary
Hui Zhang, Xiaohu Mi, Bowen Kang, Yunkai Wu, Tingting Zhang, Pai Liu, Xiaowei Sun, Zhenglong Zhang, Ning Liu, Hongxing Xu
Summary: Colloidal nanocrystals play a significant role in optoelectronic devices and their properties can be improved through ligand modification, which can enhance charge transport and emission characteristics in LEDs.
Article
Biochemistry & Molecular Biology
Yunwu Yu, Chunyang Xie, Yan Wu, Peng Liu, Ye Wan, Xiaowei Sun, Lihua Wang, Yinan Zhang
Summary: A novel composite membrane was developed by casting chitosan and polyvinyl alcohol on a glass fiber microporous membrane. The addition of chitosan improved the CO2 permeance and selectivity due to the favorable CO2 affinity of the polymer coating. Chemical structure analysis showed no change after heat treatment, while SEM images revealed a dense surface of the composite membranes. The CO2 permeance and selectivity were further enhanced after wetting and heat treatment.
Article
Nanoscience & Nanotechnology
Lixuan Chen, Jinyang Zhao, Zhiqing Shi, Miao Zhou, Shengdong Zhang, Xiao Wei Sun, Xin Zhang
Summary: Semiconductor quantum rods (QRs) emit polarized light and have great potential for energy-efficient and color-enhancing modern display devices. We present the stretching of an aligned QR polarized film to improve brightness and optical efficiency in quantum-dot based displays. The study of QR material, stretching ratio, and alignment degree guides the fabrication of highly polarized QR film. A large-area film with an alignment degree of 0.635 achieved more than 1.6-fold enhancement in brightness and transmittance compared to traditional structures, making it a viable option for various energy-saving display devices.
Article
Nanoscience & Nanotechnology
Hongmei Zhu, Qingqian Wang, Kun Sun, Wei Chen, Jun Tang, Junjie Hao, Zhaojin Wang, Jiayun Sun, Wallace C. H. Choy, Peter Muller-Buschbaum, Xiao Wei Sun, Dan Wu, Kai Wang
Summary: The chirality of 2D chiral perovskite films has been significantly enhanced by a solvent modulation strategy, leading to the formation of CPL-active materials. By creating chiral perovskite/quantum dot composites, an increase in the CPL intensity was observed, attributed to the generation and transportation of spin-polarized charge carriers as well as the enlarged lattice distortion of the chiral perovskite films achieved through solvent modulation. This approach provides an effective way to construct CPL-active materials.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Physics, Applied
Xiangwei Qu, Guohong Xiang, Jingrui Ma, Pai Liu, Aung Ko Ko Kyaw, Kai Wang, Xiao Wei Sun
Summary: In this work, we find that blue quantum dot light-emitting diodes (QLEDs) exhibit electron over-injection compared to hole injection using impedance spectroscopy and capacitance-voltage characteristics analysis. We also observe the spatial distribution of the exciton recombination zone in blue QLEDs using a red quantum dot as a fluorescent sensor. Our findings provide a practical method for identifying excess carrier in blue QLEDs and have implications for other types of QLEDs.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Jiayun Sun, Zhenwei Ren, Zhaojin Wang, Haoran Wang, Dan Wu, Xiao Wei Sun, Wallace C. H. Choy, Kai Wang
Summary: A facile ionic liquid post-treatment technique is used to modify the solution-processed quasi-2D perovskite film, which enhances the radiative recombination efficiency and the photoluminescence quantum yield of the film. It also improves the hole injection and the external quantum efficiency of the blue PeLED.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Physical
Ronghuan Liu, Bihua Hu, Kai Wang, Baomin Xu, Xiao Wei Sun
Summary: Compared with polycrystalline thin films, perovskite single crystals without grain boundaries have better photovoltaic performance and stability. A green and low-cost airflow-assisted growth method has been developed for the synthesis of large quantities of high-quality and dispersed CsPbBr3 single-crystal wires under ambient conditions. This method shows great potential for optoelectronic applications and may facilitate the research of all-inorganic perovskite single crystals.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Optics
Jianxu Lan, Xiaodong Wen, Xiaowei Sun, Xixuan Liu, Yiwen Wang, Genliang Han
Summary: The study proposes a high-optomechanical-coupling-rate heterostructure with a gradient cavity, and calculates the optomechanical rates of the single mirror and hetero-optomechanical crystal nanobeam resonators. The results show that the heterostructure based on the utilization of two mirror regions achieves better confinement of the optical and mechanical modes. Additionally, it demonstrates a mechanical breathing mode at 9.75 GHz and an optical mode with a working wavelength of 1.17 μm, with an optomechanical coupling rate g(0) = 3.81 MHz between them, and an increased mechanical quality factor of 3.18 x 10(6).
Article
Physics, Applied
Guohong Xiang, Jingrui Ma, Xiangwei Qu, Kai Wang, Hoi Sing Kwok, Xiao Wei Sun
Summary: We present transparent quantum dot light-emitting diodes (QLEDs) with a current focusing structure. By depositing a SiO2 thin film to create the current focusing structure, we achieved significantly increased DC density and luminance, reaching values of over 8700 mA/cm(2) and 360,000 cd/m(2) respectively. The impact of SiO2 thickness and aperture width on emission spectra and current densities was investigated. The current focusing design demonstrates its effectiveness and potential application in other planar LED devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Guanding Mei, Xiangtian Xiao, Sajjad Ahmad, Hong Lin, Yangzhi Tan, Kai Wang, Xiao Wei Sun, Wallace C. H. Choy
Summary: This study demonstrates the importance of microcavity design for improving the light extraction efficiency of Perovskite light-emitting diodes (PeLEDs). The experiment shows that a high-efficiency horizontal dipole in the microcavity is the key to improving the efficiency.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Physics, Applied
Wei He, Mingyuan Huang, Xiaowei Sun
Summary: This paper presents a numerical analysis of the topological valley kink states in a two-dimensional photonic crystal, focusing on both zigzag and armchair domain walls. By manipulating the triangular holes in a honeycomb structure, inequivalent valleys were created in the momentum space. The results showed that both the zigzag and armchair interfaces can support topologically protected valley kink states, providing potential applications for valley waveguides in integrated photonics.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Optics
Phil Surman, Changxiong Zheng, Chaojian Zhang, Zhenwei Yao, Xiaochuan Yang, Wenwei Xu, Xiao Wei Sun
Summary: The availability of high-resolution display panels has made glasses-free 3D displays a viable mainstream commercial product. This paper discusses the measurement of multiview 3D displays that use a slanted lenticular screen to control light directions. Understanding the image depth of field is important, in addition to the usual parameters. The aim of the paper is to describe general theory and procedure, and not the measurement of specific displays.
