Light emitting diode materials

GaN based lighting

GaN based lighting has potential to give a huge financial reward all over the world. The penetration of GaN based LED lighting to all lighting applications would imply a major improvement in efficiency and this would reduce the world power consumption by ~1000 TWh pa. with 10 % of world energy worth $100 bn used to produce light, efficiency savings would have a major impact on energy efficiency. Replacement of car headlights, fluorescent tubes, and street lights require the quality of white LEDs to improve - if white LEDs were as efficient as current red ones, all lights would be replaced. Other nano materials in light emitting devices which are used in the communication sector are GaN, GaAlAs, GaAs, InGaAsP, and GaP, AlAs etc. Among nano organic LED’s Poly [2- methoxy-5-(2’-) ethylhexyloxy)-1, 4-Phenylenevinylene] (MEH-PPB) is one example. Liquid Crystals as well as having applications in displays have potential applications for improving switching speeds in telecoms by replacement of silicon. They also have potential as photonic materials leading to improved optical materials with higher resolution. LCDs continue to develop and underpin many applications – laptops, mobile phones, etc. Constant advances are being made in low power-consumption devices and displays. Further to this, development of non-display applications is becoming increasingly important: e.g. lasing and photonics, telecoms, biology / medicine, control of microwaves. Soap is an example of liquid crystal. Cyanophenyl materials, fluorinated tolans, biological membranes, phospholipids and the protein solution that is extruded by the spider to generate silk is a liquid crystal phase.

Carbon nanotube emitters

Standard electron emitters are based either on thermionic emission of electrons from heated filaments with low work functions or field emission from sharp tips. The latter generates monochromatic electron beams; however, ultrahigh vacuum and high voltages are required. Further the emission current is typically limited to several micro amperes. Carbon fibers typically 7 μm in diameters have been used as the electron emitters; however they suffer from poor reproducibility and rapid deterioration of the tip. Carbon nano tubes have high aspect ratios and small tip radius of curvature. The ability to emit electrons from the body of nano tubes was attributed to the small radius of the tubes and the presence of defects on the surface of carbon nano tubes. VII. Wireless communication Most of the communication systems are either based on radio frequency or on microwave. If proven to be effective, nano-materials will eventually replace the current materials used in all these devices. NTT Electronics Corporation has endeavored to commercialize new laser emission sources that are optimum for next-generation communication systems and applications in non-communication fields such as medicine and the environment. Wireless is an old-fashioned term for a radio receiver, referring to its use as a wireless telegraph; now the term is used to describe modern wireless connections such as in cellular networks and wireless broadband Internet.

A wireless LAN or WLAN is a wireless local area network that uses radio waves as its carrier. The backbone network usually uses cables, with one or more wireless access points connecting the wireless users to the wired network. Materials in its nano form show peculiar electric and magnetic properties. Hence nanomaterials are incorporated into wireless LAN systems to attain a magnetic resonance of suitable frequency.