A new birefringent light‐shaping polymer‐dispersed liquid crystal (PDLC) film is experimentally demonstrated for mini‐LED backlit liquid crystal displays. Due to its angle‐sensitive transmission ...properties, such a volumetric PDLC diffuser helps to spread out the backlight faster, which in turn results in fewer mini‐LEDs or thinner display panel.
By utilizing a newly developed deep-blue iridium complex along with efficient green and orange-red phosphors, we have successfully demonstrated efficient three-component phosphorescent white-emitting ...organic light-emitting devices (WOLEDs) with excellent performances. Such WOLEDs were based on the deep-blue phosphorescent OLEDs architecture with double emitting layers and double confining layers; portions of the deep-blue phosphors were selectively replaced with green and orange-red phosphors, thereby forming a structure with the green/orange-red emitting layers sandwiched between the two deep-blue emitting layers. Such three-component phosphorescent WOLEDs yielded a high color rendering index (CRI) of up to 94 and Commission Internationale de l’Eclairage (CIE) coordinates close to the ideal equal-energy white (0.33,
0.33). Furthermore, they exhibited rather stable colors and high CRI over a wide brightness range of 10
2–10
4
cd/m
2 and yielded electroluminescence efficiencies of up to 10.3%, 24.0
cd/A and 16.4
lm/W for the forward directions.
•CuSCN films were synthesized by electrochemical process.•The parameter of CuSCN films was annealing temperature.•The photoelectrochemical characteristics of CuSCN films were investigated.
Thin films ...of p-type β-CuSCN were deposited on indium–tin oxide glass substrates via electrochemical process. Various annealing temperatures (200, 300 and 400°C) were taken into consideration. The influence of annealing temperature on structural, optical, electrical and photoelectrochemical characteristics of β-CuSCN thin films were investigated. Results from X-ray diffraction indicated as-obtained β-CuSCN thin film was in a hexagonal close pack crystal structure. We found that the crystallographic orientation changed and the optical energy band gap slightly increased with increasing annealing temperatures. These properties made CuSCN films annealed at 400°C a better photoelectrochemical performance with photocurrent density of about −0.39mA/cm2 at −0.5V vs. SCE. This value is about 5 times higher than the as-deposited CuSCN film. Observed higher photocurrent density is likely due to the intrinsic of a higher charge carrier concentration, and a lower resistance within CuSCN crystal and at CuSCN/electrolyte interface.
Novel microstructure film laminated on the 8‐domain VA‐mode LCD was proposed to get better viewing angle experience. Furthermore, the viewing angle is IPS‐like level with contrast ratio > 5000, but ...the transmittance loss is less than 5% with the collimated backlight.
Optimization of the retardation value and the electrode patterns of RGB sub‐pixels in VA‐mode LCD was found to get better viewing angle experience. Furthermore, the skin color shift level is ...competitive with the conventional 8‐domain, but the transmittance loss is only less than 4%.
Recently bipolar phosphorescent host materials have attracted wide attention since they can achieve better charge balance and hence better device performance. In this work, we report the synthesis ...and physical properties of a novel bipolar host material containing the dimesityl borane/carbazole hybrid, CMesB. With a high triplet energy, CMesB is considered a promising universal host material and has been applied to phosphorescent OLEDs of various colors. Red/green/blue/white (RGBW) OLEDs based on CMesB all show high external quantum efficiencies (20.7% for red, 20.0% for green, 16.5% for blue, and 15.7% for white) at practical brightnesses. The results indicate that the bipolar host CMesB with high triplet energy has high potential in manufacturing RGBW OLEDs for display or lighting applications.
— In this work, studies on organic light‐emitting devices (OLEDs) incorporating nanoparticle‐based nanocomposite scattering layers as the internal extraction structures (i.e., between the substrate ...and the OLED structure) were concluded. By adjusting the nanoparticle sizes and concentrations, the optical properties (optical scattering and integrated transmittance) of the nanocomposite scattering layers can be widely tuned. With appropriate compositions, nanoparticle‐based nanocomposite scattering layers with strong optical scattering, high integrated transmittance, and yet enough flatness for device integration can be obtained. The use of such nanocomposite internal scattering layers provides a convenient and effective approach for simultaneously achieving large efficiency enhancement (1.96× for quantum efficiency and 2.04× for cd/A efficiency) and improving viewing characteristics (more stable colors and emission patterns over angles). The fabrication of nanoparticle‐based nanocomposite scattering films is based on solution‐processing, which is relatively simple and convenient. These features may make it highly attractive for various OLED applications and mass production.
Transparent conductive thin films such as ZnO, Al-doped ZnO (AZO), Ti-doped ZnO (TZO), and Ti, Al-codoped ZnO (TAZO) were prepared on the STN glass substrate by radio frequency sputtering. The ...thickness of as-prepared films was approximately 700 nm and the concentration of dopants was
controlled by adjusting the electrical power of sputtering. Results from X-ray diffraction patterns clearly showed that all samples were in wurtzite structure with (002) preferential orientation. They all possessed smooth surfaces with the mixture of column and core texture as indicated by
the field emission scanning electronic microscope analyses. The average transmittance ranging from 400 to 800 nm wavelength, determined by means of UV-visible spectra, TAZO (93%) was higher than AZO (90%), TZO (91%), and ZnO (86%). Electrical resistivity determined by four-point probe followed
the order of TAZO (0.91 m cm) < AZO (3.61 m cm) - TZO (3.84 m cm) ZnO (289 m cm). Observed lower resistivity of TAZO was likely attributed to the high density of crystal defects i. e., stacking faults as indicated by the high resolution transmission electron microscopy analyses.
In typical organic light-emitting devices (OLEDs), a significant portion of internally generated radiation is trapped into the surface plasmon polariton (SPP) modes, in general not accessible for ...external use. By thinning the metal electrode, the SPP modes can be coupled to the outside surface of the device. As such, one can recycle a portion of SPPs by capping the thinned metal electrode with an appropriate absorbing/re-emission medium, inducing SPP-mediated energy transfer and re-emission. Such an approach may be used for implementing double-emitting OLEDs with different emission colors on two sides and with a broad color tuning capability.
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