Reliability of LED-based Products is a Matter of Balancing Temperatures

Solid State Lighting (SSL) technologies and products are gradually pervading into our daily life. An SSL system is composed of a LED engine with a micro-electronics driver(s), integrated in a housing that also provides the optical, sensing and other functions. Knowledge of (system) reliability is crucial for not only the business success of the...

Progress in Understanding Color Maintenance in Solid-State Lighting Systems

In this paper, progresses of color maintenance, also known as color shift, in solid-state lighting (SSL) systems are thoroughly reviewed. First, color shift is introduced and a few examples are given from different real-life industrial conditions. Different degradation mechanisms in different parts of the system are also explained. Different...

Reliability and Lifetime Prediction of Remote Phosphor Plates in Solid-State Lighting Applications Using Accelerated Degradation Testing

A methodology, based on accelerated degradation testing, is developed to predict the lifetime of remote phosphor plates used in solid-state lighting (SSL) applications. Both thermal stress and light intensity are used to accelerate degradation reaction in remote phosphor plates. A reliability model, based on the Eyring relationship, is also...

Reliability and Lifetime Prediction of Remote Phosphor Plates in Solid-State Lighting Applications Using Accelerated Degradation Testing

A methodology, based on accelerated degradation testing, is developed to predict the lifetime of remote phosphor plates used in solid-state lighting (SSL) applications. Both thermal stress and light intensity are used to accelerate degradation reaction in remote phosphor plates. A reliability model, based on the Eyring relationship, is also...

Effects of Graphene Monolayer Coating on the Optical Performance of Remote Phosphors

A graphene monolayer has been successfully coated on one side of a bisphenol-A-polycarbonate (BPA-PC) plate, used as a substrate for remote phosphor applications in light-emitting diode (LED)-based products. Using a photoresist transferring method, graphene sheet has been coated on BPA-PC plates. The results show that this graphene monolayer...

Study on the Degradation of Optical Silicone Exposed to Harsh Environments

Degradation mechanisms of silicone plates under harsh environment conditions are studied in this investigation. Environmental degradation of silicone free form, used as secondary optics in Light Emitting Diode LED lighting lamps and luminaires or any other applications requiring high quality optics being used, has negative implications for the...

A review on discoloration and high accelerated testing of optical materials in LED based-products

Reduction of intensity of light output is one of the most common degradation modes in light-emitting diode (LED) systems. It starts from the failure of the various components in the system, including the chip, the driver, and optical components (i.e. phosphorous layer). The kinetics of degradation in real life applications is relatively slow...

Reliability and Lifetime Assessment of Optical Materials in LED-Based Products

Lumen depreciation is one of the major failure modes in light-emitting diode (LED) systems. It originates from the degradation of the different components within the system, including the chip, the driver, and the optical materials (i.e., phosphorous layer). The kinetics of degradation in real-life applications is relatively slow, and in most...

Degradation of bisphenol-a-polycarbonate (BPA-PC) optical lenses under simulated harsh environment conditions

This paper investigates degradation and failure mechanisms of BPA-PC lenses in simulated harsh environment conditions. Exposure of secondary optics in Light Emitting Diode LED-based systems or any other similar applications to environmental stresses can adversely effect the performance and lifetime of products. This paper simulates a harsh...

Towards multi-functional SiO₂ @YAG: Ce core–shell optical nanoparticles for solid state lighting applications

This paper aims to investigate the synthesis, structure, and optical properties of SiO₂ @YAG:Ce core–shell optical nanoparticles for solid state lighting applications. YAG:Ce phosphor is a key part in white light emitting diodes (LEDs), with its main functionality being the generation of yellow light. Generated yellow light from...

Degradation of optical materials in solid-state lighting systems

In this paper, degradation mechanisms of optical materials, used in the light emitting diode (LED)-based products, are reviewed. The LED lighting is one of the fastest technology shifts in human history. Lighting accounts for almost 20% of the global electrical energy use, inferring that replacement of traditional lighting sources with LEDs...

Facile synthesis of ag nanowire/tio2 and ag nanowire/tio2/go nanocomposites for photocatalytic degradation of rhodamine b

This paper investigates the photocatalytic characteristics of Ag nanowire (AgNW)/TiO2 and AgNW/TiO2/graphene oxide (GO) nanocomposites. Samples were synthesized by the direct coating of TiO2 particles on the surface of silver nanowires. As-prepared AgNW/TiO2 and AgNW/TiO2/GO nanocomposites were characterized by electron microscopy, X-ray...

Degradation and Failures of Polymers Used in Light-Emitting Diodes

In this chapter, degradation mechanisms of optical materials, used in the light-emitting diode (LED)-based products, are explained. This chapter aims at describing the service conditions on the degradation mechanisms of different organic optical materials in LEDs which lead to the color shift of the light output. The contributions of different...

Outlook: From Physics of Failure to Physics of Degradation

In the foregoing chapters, the reliability of organic compounds in microelectronics and optoelectronics was discussed. It provided a state of the art in reliability concepts for materials used in electronic products. It also enlightened the direction in reliability concepts for these products. In this chapter, we discuss the outlook where we...

Degradation of silicone-based sealing materials used in microelectronics

Adhesive bonding is a key joining technology in many industrial applications, including automotive, aerospace industries, biomedical devices, and microelectronic components. Adhesive bonding is gaining more and more attention due to the increasing demand for joining similar or dissimilar components, mostly within the framework of designing...