scholarly journals Giant excitonic upconverted emission of two-dimensional semiconductor in doubly resonant plasmonic nanocavity

2021 ◽  
Author(s):  
Pengfei Qi ◽  
Yuchen Dai ◽  
Luo Yang ◽  
Guangyi Tao ◽  
Liheng Zheng ◽  
...  
Keyword(s):  
Energy Density ◽  
Excitation Energy ◽  
Optical Transition ◽  
Transition Strength ◽  
Two Dimensional ◽  
Light Collection ◽  
Efficiency Enhancement ◽  
Excitation Rate ◽  
Optical Refrigeration ◽  
2D Semiconductors

Abstract Phonon-assisted upconverted emission lies at the heart of energy harvesting, bioimaging, optical cryptography and optical refrigeration. It has been demonstrated that the emerging two-dimensional (2D) semiconductors can provide a great platform for efficient phonon-assisted upconversion due to the enhanced optical transition strength and phonon-exciton interaction of 2D excitons. However, the research on the further enhancement of excitonic upconverted emission in 2D semiconductors is almost blank. Here we report the enhanced multiphoton upconverted emission of 2D excitons in doubly resonant plasmonic nanocavity. Owing to the enhanced light collection, enhanced excitation rate and quantum efficiency enhancement arising from Purcell effect, the upconverted emission amplification of > 1000 folds and the decrease of 2 ~ 3 orders of magnitude for saturated excitation energy density are achieved. These findings pave the way to the development of excitonic upconversion lasing, nanoscopic thermometry and sensing, and open up the possibility of optical refrigeration in future 2D electronic or excitonic devices.

Flexo-photoelectronic effect in n-type/p-type two-dimensional semiconductors and a deriving light-stimulated artificial synapse

2021 ◽  
Author(s):  
Xiang Wang ◽  
Xin Zhou ◽  
Anyang Cui ◽  
Menghan Deng ◽  
Xionghu Xu ◽  
...  
Keyword(s):  
Two Dimensional ◽  
2D Semiconductors ◽  
Artificial Synapse ◽  
P Type

We demonstrate flexo-photoelectronic effects of both n-type and p-type 2D semiconductors.

Exciton dynamics and annihilation in WS2 2D semiconductors

Nanoscale ◽  
2015 ◽  
Vol 7 (16) ◽  
pp. 7402-7408 ◽  
Author(s):  
Long Yuan ◽  
Libai Huang
Keyword(s):  
Two Dimensional ◽  
Time Resolved ◽  
Exciton Dynamics ◽  
2D Semiconductors ◽  
Time Resolved Photoluminescence ◽  
2D Crystals

We systematically investigate the exciton dynamics in monolayered, bilayered, and trilayered WS2 two-dimensional (2D) crystals by time-resolved photoluminescence (TRPL) spectroscopy.

scholarly journals NEGATIVE ENERGY DENSITIES IN QUANTUM FIELD THEORY

2010 ◽  
Vol 25 (11) ◽  
pp. 2355-2363 ◽  
Author(s):  
L. H. FORD
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Energy Density ◽  
Negative Energy ◽  
Mean Value ◽  
Quantum Field ◽  
Two Dimensional ◽  
Vacuum Fluctuations ◽  
Negative Energy Density ◽  
Dimensional Spacetime

Quantum field theory allows for the suppression of vacuum fluctuations, leading to sub-vacuum phenomena. One of these is the appearance of local negative energy density. Selected aspects of negative energy will be reviewed, including the quantum inequalities which limit its magnitude and duration. However, these inequalities allow the possibility that negative energy and related effects might be observable. Some recent proposals for experiments to search for sub-vacuum phenomena will be discussed. Fluctuations of the energy density around its mean value will also be considered, and some recent results on a probability distribution for the energy density in two dimensional spacetime are summarized.

The Nonlinear Optical Transition Bleaching in Tellurene

Nanoscale ◽  
2021 ◽  
Author(s):  
Yiduo Wang ◽  
Yingwei Wang ◽  
Yulan Dong ◽  
Li Zhou ◽  
Hao Wei ◽  
...  
Keyword(s):  
Optical Properties ◽  
Optical Anisotropy ◽  
Nonlinear Optical ◽  
Optical Transition ◽  
Nonlinear Optical Properties ◽  
Two Dimensional ◽  
Linear And Nonlinear

To date, outstanding linear and nonlinear optical properties of tellurene, caused by multiple two-dimensional (2D) phases and optical anisotropy, have been attracted considerable interest for potential nanophotonics applications. In this...

Safety and Efficiency Enhancement in LNG Terminals

2017 ◽  
pp. 1584-1596
Author(s):  
Ravinder Singh ◽  
Helen Huiru Lou
Keyword(s):  
High Risk ◽  
Energy Density ◽  
Natural Gas ◽  
Process Simulation ◽  
Simulation Software ◽  
Liquefied Natural Gas ◽  
Efficiency Enhancement ◽  
Plant Operation ◽  
Aspen Hysys ◽  
Safety Enhancement

Liquefaction of natural gas helps in transporting it over long distances by sea vessels. It is then regasified and transported through pipelines to the consumer. Due to large energy density of Liquefied Natural Gas (LNG), and associated flammability issues, the LNG terminal involves high risk. Consequently, safety is an important factor in the operation of LNG terminals. Although a substantial amount of time money and effort has been put in this area, there is always some possibility of improving the process so that less risk is involved. Rapid advancement in process simulation software like Aspen Plus and Aspen HYSYS, has led to the convenience of experimenting the various control methodologies on the computer offline from the actual plant operation, before they are implemented in real time. In this chapter, main hazards associated with LNG terminal operation will be highlighted. Further, recent advancements in research for safety enhancement and efficiency enhancement in the liquefaction and regasification processes will also be included.

Simultaneously enhanced discharge energy density and efficiency in nanocomposite film capacitors utilizing two-dimensional NaNbO3@Al2O3 platelets

Nanoscale ◽  
2019 ◽  
Vol 11 (21) ◽  
pp. 10546-10554 ◽  
Author(s):  
Zhongbin Pan ◽  
Qiling Ding ◽  
Lingmin Yao ◽  
Shuangwu Huang ◽  
Shuang Xing ◽  
...  
Keyword(s):  
Energy Density ◽  
Nanocomposite Film ◽  
Nanocomposite Films ◽  
Two Dimensional ◽  
Discharge Energy ◽  
High Discharge ◽  
Discharge Efficiency ◽  
Discharge Energy Density

Nanocomposite films loaded with small 2D NaNbO3@Al2O3 platelets exhibit a high discharge energy density of 14.59 J cm−3 and simultaneously an outstanding discharge efficiency of 70.1%.

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