Progress toward blue-emitting (460–475 nm) nanomaterials in display applications

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Maksym F. Prodanov ◽  
Valerii V. Vashchenko ◽  
Abhishek K. Srivastava

Abstract Recently, quantum dots (QD) and quantum rods (QRs) have become extremely popular in displays and lighting applications. Liquid crystal displays (LCDs) equipped with quantum dot enhancement films (QDEFs) offer extended color saturation, increasing said saturation from 60 to 70% to more than 100% of the NTSC color gamut. A plethora of research dealing with EL/PL properties and the device-based performance of these materials has been published. The tunable emission wavelength and the narrow emission bandwidth are the key features of quantum dots and perovskite nanoparticles that primarily depend on the nanoparticle size and material composition. QRs, in contrast, have a core–shell structure and emit polarized light that can roughly double the efficiency of modern displays. However, blue emission for QRs, because of the large bathochromic redshift during shell growth, is a serious problem. Besides photoluminescence, electroluminescence is also important for display applications. These QD-LEDs show a lower turn ON voltage in comparison to organic LEDs, which is very important for high-resolution displays. The solution-processed narrower emission QD-LEDs have already achieved efficiency and a brightness comparable to vacuum-deposited phosphorescent organic LEDs (OLEDs). However, the blue-emitting nanoparticles and their short operational lifetime are the key obstacles in the progression of these devices. Furthermore, recently the display and lighting industry are trying to reduce the short-wavelength emissions, particularly in the spectral region below 455 nm, which has a much greater impact on human ocular health and circadian rhythm. Thus, industries are aiming at blue light in the spectral range of 460–475 nm. This spectral range is very challenging for nanomaterials because of the limited choice of materials. In this review, we summarize the recent progress made in the blue-emitting nanomaterials with a different morphology and composition. This includes recent developments in low Cd materials. Both the PL and EL properties of these materials have been discussed depending on the NP’s shape and material composition. This review also aims to discuss the various device architectures employing blue-emitting NPs, any recent achievements and future challenges.

2019 ◽  
Vol 30 (12) ◽  
pp. 11378-11382
Author(s):  
F. Heydaripour ◽  
M. Molaei ◽  
M. Karimipour ◽  
F. Dehghan ◽  
E. Mollahosseini

2019 ◽  
Vol 10 (5) ◽  
pp. 943-952 ◽  
Author(s):  
Chenghao Bi ◽  
Shixun Wang ◽  
Qiang Li ◽  
Stephen V. Kershaw ◽  
Jianjun Tian ◽  
...  

2014 ◽  
Vol 33 (2-3) ◽  
pp. 641-655 ◽  
Author(s):  
Michael T. Schweizer ◽  
Charles G. Drake

2010 ◽  
Vol 654-656 ◽  
pp. 1130-1133 ◽  
Author(s):  
Christopher J. Summers ◽  
Hisham M. Menkara ◽  
Richard A. Gilstrap ◽  
Mazen Menkara ◽  
Thomas Morris

We report the development of new nanoparticle phosphors and quantum dot structures designed for applications to enhance the color rendering and efficiency of high brightness white LEDs, as well as for bio-sensing applications. The intrinsic problem of self-absorption, high toxicity, and high sensitivity to thermal quenching of conventional quantum dot systems has prevented their adoption to LED devices. Doped Cd-free quantum dots may circumvent these issues due to their distinct Stokes shift and improved stability at high temperature. We report on the modification of Mn-doped ZnSe/ZnS core-shell quantum dots for application to the (blue diode + yellow emitter) white LED system. Band gap tuning for 460 nm excitation, inorganic shell growth and in-situ monitoring for enhanced efficiency, and analysis of thermal stability will are reported.


Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3368 ◽  
Author(s):  
Kefilwe Mokwebo ◽  
Oluwatobi Oluwafemi ◽  
Omotayo Arotiba

We report the preparation of poly (propylene imine) dendrimer (PPI) and CdTe/CdSe/ZnSe quantum dots (QDs) as a suitable platform for the development of an enzyme-based electrochemical cholesterol biosensor with enhanced analytical performance. The mercaptopropionic acid (MPA)-capped CdTe/CdSe/ZnSe QDs was synthesized in an aqueous phase and characterized using photoluminescence (PL) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), X-ray power diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy. The absorption and emission maxima of the QDs red shifted as the reaction time and shell growth increased, indicating the formation of CdTe/CdSe/ZnSe QDs. PPI was electrodeposited on a glassy carbon electrode followed by the deposition (by deep coating) attachment of the QDs onto the PPI dendrimer modified electrode using 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS) as a coupling agent. The biosensor was prepared by incubating the PPI/QDs modified electrode into a solution of cholesterol oxidase (ChOx) for 6 h. The modified electrodes were characterized by voltammetry and impedance spectroscopy. Since efficient electron transfer process between the enzyme cholesterol oxidase (ChOx) and the PPI/QDs-modified electrode was achieved, the cholesterol biosensor (GCE/PPI/QDs/ChOx) was able to detect cholesterol in the range 0.1–10 mM with a detection limit (LOD) of 0.075 mM and sensitivity of 111.16 μA mM−1 cm−2. The biosensor was stable for over a month and had greater selectivity towards the cholesterol molecule.


2018 ◽  
Vol 03 (03n04) ◽  
pp. 1840002 ◽  
Author(s):  
Dandan Lyu ◽  
Shaofan Li

The development of crystal plasticity theory based on dislocation patterns dynamics has been an outstanding problem in materials science and condensed matter of physics. Dislocation is the origin of crystal plasticity, and it is both the individual dislocation behavior as well as the aggregated dislocations behaviors that govern the plastic flow. The interactions among dislocations are complex statistical and stochastic events, in which the spontaneous emergence of organized dislocation patterns formations is the most critical and intriguing events. Dislocation patterns consist of quasi-periodic dislocation-rich and dislocation poor regions, e.g. cells, veins, labyrinths, ladders structures, etc. during cyclic loadings. Dislocation patterns have prominent and decisive effects on work hardening and plastic strain localization, and thus these dislocation micro-structures are responsible to material properties at macroscale. This paper reviews the recent developments of experimental observation, physical modeling, and computer modeling on dislocation microstructure. In particular, we focus on examining the mechanism towards plastic deformation. The progress and limitations of different experiments and modeling approaches are discussed and compared. Finally, we share our perspectives on current issues and future challenges in both experimental, analytical modeling, and computational aspects of dislocation pattern dynamics.


Author(s):  
Luciano Mescia ◽  
Pietro Bia ◽  
Onofrio Losito

This chapter summarizes the physical properties of THz antennas, provides a summary of some of the most important recent developments in the field of energy harvesting of Earth long-wave infrared radiation, discusses the potential applications and identifies the future challenges and opportunities. In particular, a THz antenna is designed in order to transform the thermal energy, provided by the Sun and re-emitted from the Earth, in electricity. The proposed antenna is a square spiral of gold printed on a low cost dielectric substrate. Simulations have been conducted in order to investigate the behavior of the antenna illuminated by a circularly polarized plane wave with an amplitude chosen according to the Stefan-Boltzmann radiation law. Moreover, these THz antennas could be coupled with other components to obtain direct rectification of T radiation. As a consequence, these structures further optimized could be a promising alternative to the conventional photovoltaic solar cells.


Author(s):  
Ruhul Khalil ◽  
Mohammad Babar ◽  
Tariqullah Jan ◽  
Nasir Saeed

2019 ◽  
Vol 6 (10) ◽  
pp. 2009-2015 ◽  
Author(s):  
Zhiwen Yang ◽  
Qianqian Wu ◽  
Gongli Lin ◽  
Xiaochuan Zhou ◽  
Weijie Wu ◽  
...  

An all-solution processed inverted green quantum dot-based light-emitting diode with concurrent high efficiency and long lifetime is obtained by precisely controlled double shell growth of quantum dots.


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