We investigate the effects of the refractive index of the encapsulant on the light-extraction efficiency (LEE) of light-emitting diodes (LEDs) for GaN LEDs (n ≈ 2.5) and AlGaInP LEDs (n ≈ 3.0). For non-absorbing rectangular parallelepiped LED chips, as the refractive index of the encapsulant increases, the LEE first increases quasi-linearly, then increases sub-linearly, and finally a saturation is reached. Furthermore, LEDs with a dual-layer graded-refractive-index (GRIN) encapsulant (n(encapsulant 1) = 1.57 and n(encapsulant 2) = 1.41) is fabricated through a two-step curing process. We demonstrate that such an LED further enhances the LEE by reducing Fresnel reflection loss at the encapsulant/air interface by 35% compared with an LED encapsulated with a single-layer encapsulant (n(encapsulant) = 1.57).
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/OE.19.0A1135 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Bright, circularly polarized black-body radiation from twisted nanocarbon filaments.
Science
December 2024
Center for Complex Particle Systems (COMPASS), University of Michigan, Ann Arbor, MI, USA.
Planck's law ignores but does not prohibit black-body radiation (BBR) from being circularly polarized. BBR from nanostructured filaments with twisted geometry from nanocarbon or metal has strong ellipticity from 500 to 3000 nanometers. The submicrometer-scale chirality of these filaments satisfies the dimensionality requirements imposed by fluctuation-dissipation theorem and requires symmetry breaking in absorptivity and emissivity according to Kirchhoff's law.
View Article and Find Full Text PDFNarrowband emission and enhanced stability in top-emitting OLEDs with dual resonant cavities.
Mater Horiz
December 2024
Macao Institute of Materials Science and Engineering (MIMSE), MUST-SUDA Joint Research Center for Advanced Functional Materials, Zhuhai MUST Science and Technology Research Institute, Macau University of Science and Technology, Taipa 999078, Macau, China.
Capping layers (CPLs) are commonly employed in top-emitting organic light-emitting diodes (TEOLEDs) due to their ability to optimize color purity, enhance external light out-coupling efficiency, and improve device stability. However, the mismatch in refractive index between CPLs and thin film encapsulation (TFE) often induces light trapping. This study introduces a novel approach by combining a low refractive index material, lithium fluoride (LiF), with the traditional TFE material, silicon nitride (SiN), to form a combined CPL (LiF/SiN), resulting in improved light outcoupling and light reflection properties.
View Article and Find Full Text PDFStructural, Mechanical, and Optical Properties of Laminate-Type Thin Film SWCNT/SiON Composites.
Nanomaterials (Basel)
November 2024
Department of Materials and Environmental Technology, School of Engineering, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia.
The development of new encapsulating coatings for flexible solar cells (SCs) can help address the complex problem of the short lifespan of these devices, as well as optimize the technological process of their production. In this study, new laminate-type protective composite coatings were prepared using a silicon oxynitride thin-film matrix obtained by curing the pre-ceramic polymer perhydropolysilazane (PHPS) through two low-temperature methods: (i) thermal annealing at 180 °C and (ii) exposure to UV radiation at wavelengths of 185 and 254 nm. Single-walled carbon nanotubes (SWCNTs) were used as fillers via dry transfer, facilitating their horizontal orientation within the matrix.
View Article and Find Full Text PDFValidation by in-vitro digestion and sensory analysis of incorporating vegetable oil encapsulates in cottage cheese.
Food Chem
February 2025
Agroindustrial processes research group, Faculty of Engineering, Universidad de La Sabana Campus del Puente del Común, Km. 7, vía Autopista Norte Bogotá, Colombia. Electronic address:
Malnutrition is a global issue linked to energy or nutrient imbalances, often resulting in deficiencies or overweight. Dairy products, rich in macronutrients and micronutrients, are a potential solution. However, processing, storage, and digestion can lead to nutrient loss.
View Article and Find Full Text PDFA vector magnetic field sensor based on a ferrofluid-encapsulated coreless D-shaped fiber is proposed and demonstrated. The core of the singlemode fiber (SMF) is completely removed by fiber polishing technology, and the remaining part transformed into a multimode interference (MMI) waveguide. The exposed side-polishing plane enable the evanescent field to interact with surrounding magnetic fluid (MF).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!