The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Quantum dots (QDs) have broad prospect in illumination and display in the future with their high quantum efficiency, tunable color in the entire visible range, and excellent color rendering ability. QDs are generally prepared as remote films in white light-emitting diodes(WLED), which gives rise to low light conversion efficiency (LCE). In order to enhance the LCE of QD-converted WLED (QCWLED), a...
In this letter, remote quantum dot phosphor-converted light-emitting diodes (QD-LEDs) with air encapsulation, silicone lens, and silicone encapsulation were fabricated. The effects of different packaging methods on the optical and thermal performances of QD-LEDs were evaluated based on the experimental tests and simulation. Optical efficiency and spectral stability were tested by experiment, and the...
Angular color uniformity (ACU) of a king of popular remote phosphor coating LED packaging with spherical phosphor shape with uniform thickness was invested by the Monte Carlo ray tracing method. The simulation results indicate the yellowish ring can't be avoided under uniform phosphor thickness in angular range of 0°–180°. The optimized phosphor geometry was proposed whose thickness gradually reduces...
Low light extraction efficiency (LEE) is one of the most challenging points for light-emitting diode (LED) array packaging. Analysis of LEE enhancement of LED array packaging with micro-structures on packaging silicone is presented. To obtain high LEE, micro-structures including inversed cone, inversed frustum of a pyramid (FP) and V-groove are introduced. Two types of LED chips consisting of conventional...
The color uniformity is a critical index in the evaluation of high quality white light emitting diodes (LEDs). The main factor affecting the color distribution is the state of the phosphor. The secondary factor is the optical structure. This paper analyzes two parameters of the phosphor layer (thickness and concentration) and six optical structures. Results indicate that the structures with reflector...
Optical analysis is critical to the evaluation of an LED MR16 lamp, especially when the lamp is still in its early stage of development and applications and when optimization is needed for making use of unique characteristics of LEDs. In this study, optical research of a 3W LED MR16 lamp was conducted. The experimental results demonstrated that the LED MR16 lamppsilas angle of full width at half intensity...
The state of phosphor will greatly influence the packaging performance such as luminous efficiency, quality of white light and color uniformity. The analysis presents that the small variations of thickness and concentration could significantly influence the light extraction efficiency and the correlated color temperature (CCT). With the increase of thickness and concentration, the light extraction...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.