A hybrid multifunctional perovskite with dielectric phase transition and broadband red-light emission

2021 ◽  
pp. 130468
Author(s):  
Fo-Ling Zhou ◽  
Shuang-Teng Song ◽  
Meng-Meng Lun ◽  
Hao-nan Zhu ◽  
Kun Ding ◽  
...  
RSC Advances ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 2329-2336
Author(s):  
Yanyan Li ◽  
Liting Lin ◽  
Jie Yang ◽  
Kun Qian ◽  
Tao Jiang ◽  
...  

The luminescence of dielectric phase transition materials is one important property for technological applications, such as low-energy electron excitation.


2021 ◽  
Author(s):  
Yu-Zhen Wang ◽  
Zhi-Xu Zhang ◽  
Chang-Yuan Su ◽  
Tie Zhang ◽  
Da-Wei Fu ◽  
...  

A hybrid perovskite material with dielectric phase transition obtained by the introduction of a moving group.


Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 58
Author(s):  
Hiromi Nakano ◽  
Shota Ando ◽  
Konatsu Kamimoto ◽  
Yuya Hiramatsu ◽  
Yuichi Michiue ◽  
...  

We prepared four types of Eu2O3- and P2O5-doped Ca2SiO4 phosphors with different phase compositions but identical chemical composition, the chemical formula of which was (Ca1.950Eu3+0.013☐0.037)(Si0.940P0.060)O4 (☐ denotes vacancies in Ca sites). One of the phosphors was composed exclusively of the incommensurate (IC) phase with superspace group Pnma(0β0)00s and basic unit-cell dimensions of a = 0.68004(2) nm, b = 0.54481(2) nm, and c = 0.93956(3) nm (Z = 4). The crystal structure was made up of four types of β-Ca2SiO4-related layers with an interlayer. The incommensurate modulation with wavelength of 4.110 × b was induced by the long-range stacking order of these layers. When increasing the relative amount of the IC-phase with respect to the coexisting β-phase, the red light emission intensity, under excitation at 394 nm, steadily decreased to reach the minimum, at which the specimen was composed exclusively of the IC-phase. The coordination environments of Eu3+ ion in the crystal structures of β- and IC-phases might be closely related to the photoluminescence intensities of the phosphors.


Author(s):  
Chaopeng Tan ◽  
Nan Zhou ◽  
Fen Wang ◽  
Keshuang Tang ◽  
Yangbeibei Ji

At high-speed intersections in many Chinese cities, a traffic-light warning sequence at the end of the green phase—three seconds of flashing green followed by three seconds of yellow—is commonly implemented. Such a long phase transition time leads to heterogeneous decision-making by approaching drivers as to whether to pass the signal or stop. Therefore, risky driving behaviors such as red-light running, abrupt stop, and aggressive pass are more likely to occur at these intersections. Proactive identification of risky behaviors can facilitate mitigation of the dilemma zone and development of on-board safety altering strategies. In this study, a real-time vehicle trajectory prediction method is proposed to help identify risky behaviors during the signal phase transition. Two cases are considered and treated differently in the proposed method: a single vehicle case and a following vehicle case. The adaptive Kalman filter (KF) model and the K-nearest neighbor model are integrated to predict vehicle trajectories. The adaptive KF model and intelligent driver model are fused to predict the following vehicles’ trajectories. The proposed models are calibrated and validated using 1,281 vehicle trajectories collected at three high-speed intersections in Shanghai. Results indicate that the root mean square error between the predicted trajectories and the actual trajectories is 5.02 m for single vehicles and 2.33 m for following vehicles. The proposed method is further applied to predict risky behaviors, including red-light running, abrupt stop, aggressive pass, speeding pass, and aggressive following. The overall prediction accuracy is 95.1% for the single vehicle case and 96.2% for the following vehicle case.


2004 ◽  
Vol 126 (1) ◽  
pp. 291-294 ◽  
Author(s):  
Tomoyuki Akutagawa ◽  
Sadamu Takeda ◽  
Tatsuo Hasegawa ◽  
Takayoshi Nakamura

2022 ◽  
Author(s):  
Dingrong Liu ◽  
Zenghua Cai ◽  
Yu-Ning Wu ◽  
Shiyou Chen

Abstract The γ-phase Cuprous Iodide (CuI) emerges as a promising transparent p-type semiconductor for next-generation display technology because of its wide direct band gap, intrinsic p-type conductivity, and high carrier mobility. Two main peaks are observed in its photoluminescence (PL). One is short wavelength (410-430 nm) emission, which is well attributed to the electronic transitions at Cu vacancy, whereas the other long wavelength emission (680-720 nm) has not been fully understood. In this paper, through first-principles simulations, we investigate the formation energies and emission line shape for various defects, and discover that the intrinsic point defect cluster V_I+Cu_i^(2+) is the source of the long wavelength emission. Our finding is further supported by the prediction that the defect concentration decreases dramatically as the chemical condition changes from Cu-rich to I-rich, explaining the significant reduction in the red light emission if CuI is annealed in abundant I environment.


2010 ◽  
Vol 39 (3) ◽  
pp. 168-169 ◽  
Author(s):  
Tsuyoshi Michinobu ◽  
Haruka Osako ◽  
Kimie Murata ◽  
Kiyotaka Shigehara

2003 ◽  
Vol 125 (3) ◽  
pp. 636-637 ◽  
Author(s):  
Xiwen Chen ◽  
Jin-Long Liao ◽  
Yongmin Liang ◽  
M. O. Ahmed ◽  
Hao-En Tseng ◽  
...  

2018 ◽  
Vol 13 (19) ◽  
pp. 2916-2922 ◽  
Author(s):  
Qing Wang ◽  
Wan-Ying Zhang ◽  
Ping-Ping Shi ◽  
Qiong Ye ◽  
Da-Wei Fu

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