In terms of ET to develop new phosphors, using Eu 2+ or Ce 3+ as the sensitizer, we described 12 kinds of ET systems, such as Ce 3+вЂ“Mn 2+, Ce 3+вЂ“Tb 3+, Ce 3+вЂ“Tb 3+вЂ“Mn 2+, Eu 2+вЂ“Mn 2+, Eu 2+вЂ“Tb 3+, Eu 3+вЂ“Tb 3+вЂ“Mn 2+ and so on. For the design and discovery of novel phosphor via the structurally design principles, we described the latest research progress of the several most common phosphors systems for wLEDs, including aluminate, silicate, borate, sulfide, phosphate and the Mn 4+ or Eu 3+ doped phosphors. Subsequently, we focused on the summary of design and discovery of novel phosphor host materials via the structurally design principles and ET viewpoint, which is generally efficient in the optimization of the commercially used LED phosphors.

In this chapter, we summarized five fundamental requirements for phosphors used in wLEDs and four commercial phosphors for wLEDs. Accordingly, the related optical parameters, such as luminous efficiency, CRI and CCT are strongly dependent on the physical properties of the selected phosphors. WLED solid-state lighting technology has received extensive attention in these years, and phosphor materials act as one kind of key components in fabrication of wLEDs devices. Zhanchao Wu, Zhiguo Xia, in Nitride Semiconductor Light-Emitting Diodes (LEDs) (Second Edition), 2018 5.5 Future development of wLEDs phosphors As the operational period is quite small, since the light switches off again after several seconds, the overall power consumption is low despite the brightness of the light. A sensor circuit is typically used to turn the lights on when someone passes, for example. Security lighting: Again these are a direct equivalent to mains-powered devices. Marker lights: Solar markers, usually with LEDs as the light source, are used to mark steps, paths, and obstacles.

Several lights may be used to create an overall effect.

The lights are designed to illuminate a patio, feature, or area of the garden.Дecorative accent lighting: Typically less bright than the area lights, accent lighting is used to provide a point of interest and to cast a glow in the immediate vicinity. A bewildering variety of lights is available, mainly in four distinct groups.ДЄrea illumination: These lights are solar equivalents of the mains-powered lighting, which has been available for years. Probably the first thin-film powered light at that time was the Chronar WalkLite range, which achieved significant sales despite some initial technical problems. Solar lighting products first came to prominence in the mid-1980s with offerings from Siemens and Brinkmann, amongst others.

Visual lighting technologies