scholarly journals Silicon Nanoscale Materials: From Theoretical Simulations to Photonic Applications

2012 ◽  
Vol 2012 ◽  
pp. 1-21 ◽  
Author(s):  
Leonid Khriachtchev ◽  
Stefano Ossicini ◽  
Fabio Iacona ◽  
Fabrice Gourbilleau
Keyword(s):  
Nanoscale Materials ◽  
Single Chip ◽  
Research Activity ◽  
Light Emitting ◽  
Practical Applications ◽  
Si Photonics ◽  
Optical Functions ◽  
Low Efficiency ◽  
Theoretical Simulations ◽  
Remarkable Progress

The combination of photonics and silicon technology is a great challenge because of the potentiality of coupling electronics and optical functions on a single chip. Silicon nanocrystals are promising in various areas of photonics especially for light-emitting functionality and for photovoltaic cells. This review describes the recent achievements and remaining challenges of Si photonics with emphasis on the perspectives of Si nanoscale materials. Many of the results and properties can be simulated and understood based on theoretical studies. However, some of the key questions like the light-emitting mechanism are subjects of intense debates despite a remarkable progress in the recent years. Even more complex and important is to move the known experimental observations towards practical applications. The demonstrated devices and approaches are often too complex and/or have too low efficiency. However, the challenge to combine optical and electrical functions on a chip is very strong, and we expect more research activity in the field of Si nanophotonics in the future.

scholarly journals Lead-Free Perovskite Single Crystals: A Brief Review

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1329
Author(s):  
Xianfang Zhou ◽  
Yansong Wang ◽  
Chuangye Ge ◽  
Bin Tang ◽  
Haoran Lin ◽  
...  
Keyword(s):  
Single Crystals ◽  
Diffusion Length ◽  
Low Cost ◽  
Lead Free ◽  
The Novel ◽  
Preparation Methods ◽  
Light Emitting ◽  
Practical Applications ◽  
Interfacial Engineering ◽  
Remarkable Progress

Lead-free perovskites have received remarkable attention because of their nontoxicity, low-cost fabrication, and spectacular properties including controlled bandgap, long diffusion length of charge carrier, large absorption coefficient, and high photoluminescence quantum yield. Compared with the widely investigated polycrystals, single crystals have advantages of lower trap densities, longer diffusion length of carrier, and extended absorption spectrum due to the lack of grain boundaries, which facilitates their potential in different fields including photodetectors, solar cells, X-ray detectors, light-emitting diodes, and so on. Therefore, numerous research focusing on the novel properties, preparation methods, and remarkable progress in applications of lead-free perovskite single crystals (LFPSCs) has been extensively studied. In this review, the current advancements of LFPSCs are briefly summarized, including the synthesis approaches, compositional and interfacial engineering, and stability of several representative systems of LFPSCs as well as the reported practical applications. Finally, the critical challenges which limit the performance of LFPSCs, and their inspiring prospects for further developments are also discussed.

Tetraphenylbenzene-based AIEgens: the Horizontally Oriented Emitters for highly Efficient Non-doped Deep Blue OLEDs and Host for High-Performance Hybrid WOLEDs

2020 ◽  
Author(s):  
Pengbo Han ◽  
Zeng Xu ◽  
Chengwei Lin ◽  
Dongge Ma ◽  
Anjun Qin ◽  
...  
Keyword(s):  
High Performance ◽  
General Strategy ◽  
Flat Panel Displays ◽  
Light Emitting ◽  
Horizontal Orientation ◽  
Deep Blue ◽  
Full Color ◽  
High Emission ◽  
White Oleds ◽  
Low Efficiency

Deep blue organic-emitting fluorophores are crucial for application in white lighting and full color flat-panel displays but emitters with high color quality and efficiency are rare. Herein, novel deep blue AIE luminogens (AIEgens) with various donor units and an acceptor of cyano substituted tetraphenylbenzene (TPB) cores were developed and used to fabricate non-doped deep blue and hybrid white organic light-emitting diodes (OLEDs). Benefiting from its high emission efficiency and high proportion of horizontally oriented dipoles in the film state, the non-doped deep blue device based on CN-TPB-TPA realized a maximum external quantum efficiency 7.27%, with a low efficiency roll-off and CIE coordinates of (0.15, 0.08). Moreover, efficient two-color hybrid warm white OLEDs (CIE<sub>x,y</sub> = 0.43, 0.45) were achieved using CN-TPB-TPA as the blue-emitting layer and phosphor doped host, which realized maximum current, power, external quantum efficiencies 58.0 cd A<sup>-1</sup>, 60.7 lm W<sup>-1</sup> and 19.1%, respectively. This work provides a general strategy to achieve high performance, stable deep blue and hybrid white OLEDs by construction of AIEgens with excellent horizontal orientation

Efficient organic light-emitting diodes based on iridium(III) complexes containing indolo[3,2,1-jk]carbazole derivatives with narrow emission bandwidths and low efficiency roll offs

2021 ◽  
Author(s):  
Xiang-Ji Liao ◽  
Jin-Jun Zhu ◽  
Li Yuan ◽  
Zhi-Ping Yan ◽  
Xu-Feng Luo ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Carbazole Derivatives ◽  
Highly Efficient ◽  
Organic Light ◽  
Low Efficiency ◽  
Narrow Emission

In this work, two cyclometalated ligands 2-(pyridin-2-yl)indolo[3,2,1-jk]carbazole (pyidcz) and 2-(4-(trifluoromethyl)pyridin-2-yl)indolo[3,2,1-jk]carbazole (tfpyidcz) using indolo[3,2,1-jk]carbazole unit were synthesized for highly efficient iridium(III) complexes (pyidcz)2Ir(tmd) and (tfpyidcz)2Ir(tmd) (tmd = 2,2,6,6-tetramethyl-3,5-heptanedione). The two Ir(III)...

The novel synthesis of tris-cyclometalated iridium(III) complexes for saturated red organic light-emitting diodes with low efficiency roll-off

2021 ◽  
pp. 109360
Author(s):  
Qun-bo Mei ◽  
Lei Liu ◽  
Jiu-chang Yang ◽  
Shang-hui Ye ◽  
Bi-hai Tong
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
The Novel ◽  
Light Emitting ◽  
Novel Synthesis ◽  
Organic Light ◽  
Low Efficiency

Copper(I) Complex as Sensitizer Enables High‐Performance Organic Light‐Emitting Diodes with Very Low Efficiency Roll‐Off

2021 ◽  
pp. 2106345
Author(s):  
Lisi Zhan ◽  
Ao Ying ◽  
Yanyu Qi ◽  
Kailong Wu ◽  
Yang Tang ◽  
...  
Keyword(s):  
High Performance ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light ◽  
Low Efficiency

Benzene[g]furan[2,3-B]quinoxaline-based red fluorescent material for non-doped organic light-emitting devices with low efficiency roll-off

2021 ◽  
pp. 139199
Author(s):  
ShuYa Ning ◽  
YiFan Zhang ◽  
YiXiang Li ◽  
Yuan Wu ◽  
Ke Qin ◽  
...  
Keyword(s):  
Light Emitting ◽  
Fluorescent Material ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices ◽  
Low Efficiency

scholarly journals Highly efficient all-phosphorescent white organic light-emitting diodes with low efficiency roll-off and stable-color by managing triplet excitons in emissive layer

2020 ◽  
Vol 69 (4) ◽  
pp. 047202
Author(s):  
Xin-Ming Xiao ◽  
Long-Shan Zhu ◽  
Yu Guan ◽  
Jie Hua ◽  
Hong-Mei Wang ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Emissive Layer ◽  
Highly Efficient ◽  
Organic Light ◽  
Low Efficiency ◽  
Triplet Excitons

scholarly journals A Small-Divergence-Angle Orbital Angular Momentum Metasurface Antenna

Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jianchun Xu ◽  
Ke Bi ◽  
Ru Zhang ◽  
Yanan Hao ◽  
Chuwen Lan ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Electromagnetic Waves ◽  
Divergence Angle ◽  
Compact Structure ◽  
Phase Gradient ◽  
Practical Applications ◽  
Circular Arrangement ◽  
Low Efficiency ◽  
Theoretical Analyses

Electromagnetic waves carrying an orbital angular momentum (OAM) are of great interest. However, most OAM antennas present disadvantages such as a complicated structure, low efficiency, and large divergence angle, which prevents their practical applications. So far, there are few papers and research focuses on the problem of the divergence angle. Herein, a metasurface antenna is proposed to obtain the OAM beams with a small divergence angle. The circular arrangement and phase gradient were used to simplify the structure of the metasurface and obtain the small divergence angle, respectively. The proposed metasurface antenna presents a high transmission coefficient and effectively decreases the divergence angle of the OAM beam. All the theoretical analyses and derivation calculations were validated by both simulations and experiments. This compact structure paves the way to generate OAM beams with a small divergence angle.

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