Luminescence Characteristics of Blue and Yellow Phosphor for Near-Ultraviolet

2006 ◽  
Vol 43 (5) ◽  
pp. 304-308 ◽  
2007 ◽  
Vol 44 (3) ◽  
pp. 147-151 ◽  
Author(s):  
Kyoung-Jae Choi ◽  
Soon-Duk Jee ◽  
Chang-Hae Kim ◽  
Sang-Hyuk Lee ◽  
Ho-Kun Kim

2015 ◽  
Vol 08 (04) ◽  
pp. 1550042 ◽  
Author(s):  
Jianghui Zheng ◽  
Jia Feng ◽  
Qijin Cheng ◽  
Ziquan Guo ◽  
Lihan Cai ◽  
...  

Yellow emitting Sm 3+-doped NaBa 1-x BO 3(0.01 ≤ x ≤ 0.13) phosphors were synthesized by conventional solid state reaction method. The phase structure and luminescence properties of the as-prepared phosphors were investigated. These phosphors can be effectively excited by 403 nm near-ultraviolet light and feature a satisfactory yellow performance. The emission peaks are observed at 560 nm, 603 nm and 650 nm, originating from the transitions of 4G5∕2→6H5∕2, 4G5∕2→6H7∕2 and 4G5∕2→6H9∕2 respectively. Investigation of Sm 3+ concentration-dependent emission spectra indicates that the NaBa 0.95 BO 3:0.05 Sm 3+ phosphor shows the strongest yellow emission intensity and exhibits the CIE value of x = 0.4760 and y = 0.5090. Through the theoretical calculation, a high color purity of 96.0% was determined for the NaBaBO 3: Sm 3+ phosphor, and the color purity of NaBaBO 3: Sm 3+ is much higher than that of the commercial yellow phosphor YAG : Ce 3+. This work is highly relevant to the development of a new type of potential down-conversion (DC) yellow phosphor for near ultraviolet white or yellow light-emitting diodes (LEDs).


2014 ◽  
Vol 63 (15) ◽  
pp. 157702
Author(s):  
Gao Song ◽  
Zhao Su-Ling ◽  
Xu Zheng ◽  
Yang Yi-Fan ◽  
Liu Zhi-Min ◽  
...  

2019 ◽  
Author(s):  
Matteo Campanelli ◽  
Tiziana Del Giacco ◽  
Filippo De Angelis ◽  
Edoardo Mosconi ◽  
Marco Taddei ◽  
...  

<div> <p>A novel solvent-free synthesis for Ce-UiO-66 metal-organic frameworks (MOFs) is presented. The MOFs are obtained by simply grinding the reagents, cerium ammonium nitrate (CAN) and the carboxylic linkers, in a mortar for few minutes with the addition of a small amount of acetic acid (AcOH) as modulator (1.75 eq, o.1 ml). The slurry is then transferred into a 1 ml vial and heated at 120°C for 1 day. The MOFs have been characterized for their composition, crystallinity and porosity and employed as heterogenous catalysts for the photo-oxidation reaction of substituted benzylic alcohols to benzaldaldehydes under near ultraviolet light irradiation. The catalytic performances, such as yield, conversion and kinetics, exceed those of similar systems studied by chemical oxidation and using Ce-MOF as catalyst. Moreover, the MOFs were found to be reusable up to three cycles without loss of activity. Density functional theory (DFT) calculations gave an estimation of the band-gap shift due to the different nature of the linkers used and provide useful information on the catalytic activity experimentally observed.</p> </div>


Author(s):  
Alexander Richards ◽  
Matthew Weschler ◽  
Michael Durller

Abstract To help solve the navigational problem, i.e., being able to successfully locate a circuit for probing or editing without destroying chip functionality, a near-infrared (NIR), near-ultraviolet (NUV), and visible spectrum camera system was developed that attaches to most focused ion beam (FIB) or scanning electron microscope vacuum chambers. This paper reviews the details of the design and implementation of the NIR/NUV camera system, as instantiated upon the FEI FIB 200, with a particular focus on its use for the visualization of buried structures, and also for non-destructive real time area of interest location and end point detection. It specifically considers the use of the micro-optical camera system for its benefit in assisting with frontside and backside circuit edit, as well as other typical FIB milling activities. The quality of the image obtained by the IR camera rivals or exceeds traditional optical based imaging microscopy techniques.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2758
Author(s):  
Alberto Taffelli ◽  
Sandra Dirè ◽  
Alberto Quaranta ◽  
Lucio Pancheri

Photodetectors based on transition metal dichalcogenides (TMDs) have been widely reported in the literature and molybdenum disulfide (MoS2) has been the most extensively explored for photodetection applications. The properties of MoS2, such as direct band gap transition in low dimensional structures, strong light–matter interaction and good carrier mobility, combined with the possibility of fabricating thin MoS2 films, have attracted interest for this material in the field of optoelectronics. In this work, MoS2-based photodetectors are reviewed in terms of their main performance metrics, namely responsivity, detectivity, response time and dark current. Although neat MoS2-based detectors already show remarkable characteristics in the visible spectral range, MoS2 can be advantageously coupled with other materials to further improve the detector performance Nanoparticles (NPs) and quantum dots (QDs) have been exploited in combination with MoS2 to boost the response of the devices in the near ultraviolet (NUV) and infrared (IR) spectral range. Moreover, heterostructures with different materials (e.g., other TMDs, Graphene) can speed up the response of the photodetectors through the creation of built-in electric fields and the faster transport of charge carriers. Finally, in order to enhance the stability of the devices, perovskites have been exploited both as passivation layers and as electron reservoirs.


2021 ◽  
pp. 2100023
Author(s):  
Kong‐Chao Shen ◽  
Jing‐Kun Wang ◽  
Yang Shen ◽  
Yan‐Qing Li ◽  
Ming‐Lei Guo ◽  
...  

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