Large-area GaN -based blue light-emitting diodes (LEDs) on sapphire substrates with an omnidirectional nanostructure consisted of Ag nanoparticles and TiO2/SiO2 Bragg reflector were fabricated. For the LEDs without the omnidirectional nanostructure, the spectra of the P- and S-polarization light are lightly different and the peak wavelength of P- and S-polarization light was estimated to be 464 nm and 463 nm, respectively at forward current of 20 mA. In contrast, for the LEDs with the omnidirectional nanostructure, the spectra of the P- and S-polarization light are nearly the same at forward current of 20 mA and 100 mA.
We demonstrate a simple and effective way to enhance the performance of perovskite light-emitting diodes (PeLEDs) by utilizing an alkali halide doped PEDOT:PSS as the hole transport layer (HTL). The...
A Bi3+-doped Cs2SnCl6 exhibits photoluminescence at around 456 nm and a photoluminescence quantum yield of 31%. The blue LED based on the Bi3+-doped Cs2SnCl6 phosphor exhibits a long life of 120 hours and a CIE color coordinates of (0.14, 0.11).
In this study, the optimal structure for obtaining high green color purity was investigated by modeling quantum dot (QD)–organic light-emitting diodes (OLED). It was found that even if the green quantum dot (G-QD) density in the G-QD layer was 30%, the full width at half maximum (FWHM) in the green wavelength band could be minimized to achieve a sharp emission spectrum, but it was difficult to completely block the blue light leakage with the G-QD layer alone. This blue light leakage problem was solved by stacking a green color filter (G-CF) layer on top of the G-QD layer. When G-CF thickness 5 μm was stacked, blue light leakage was blocked completely, and the FWHM of the emission spectrum in the green wavelength band was minimized, resulting in high green color purity. It is expected that the overall color gamut of QD-OLED can be improved by optimizing the device that shows such excellent green color purity.
Improved performance of GaN-based blue light emitting diodes with InGaN/GaN multilayer barriers