In 50-ies. the last century, light-emitting diodes, were not designed to operate at room temperature and should be dipped in liquid nitrogen so they could work. The first light-emitting diodes can be purchased allocated to light only in the infrared range, and in spite of this, in a short time found them a use in photoelectric sensors. In 1971, through the development of better semiconductor materials, LEDs have started to be produced in the colors green, orange and yellow. Thus, the first lamp warning LED. Only in 1993. Shuji Nakamura created the first blue LED and improved the green led is indium gallium ingan. Then he developed also the diode white.
Constant development of LEDs
Since 2006. manufactured the first light-emitting diodes with high luminous efficiency 100 LM/W. Four years later, in laboratory conditions it is possible to obtain light output of 250 LM/W. Led Technology is constantly improving, further development is directed towards OLED technology, which is considered to be the future on the lighting market. Organic light emitting diode, i.e., OLED is made of organic compounds. They are structures for flexible displays, televisions or lights the signal LEDS. OLED displays are extremely thin, and this is due to the lack of the need of backlight, since the LEDs themselves generate light.
Specification and construction
An organic led consists of several very thin layers of material superimposed on each other. Has two conductive electrodes: an anode and a cathode, another is a conductive layer and a layer issue. The substrate is often a film or glass. Thanks to the massive use of smartphones, starting with 2012. increasingly used in televisions OLED technology is becoming more widespread due to many advantages such as contrast and brightness the best of the available displays, the color reproduction is unattainable for other technologies, as well as the possibility of deformation of the screen surface. In addition, for those who care for our planet, in the production of OLED does not use mercury, making them more environmentally friendly.
Scratches on the glass
With its simple design and lack of illumination, costs of mass production is much lower compared to LCD displays and plasma panels. Less power consumption also affects the reduction in the cost of operation of the OLED display. Through the use of clear grounds, the display can show the image on both sides, giving an almost unlimited angle. Of course there are some "but" in the whole palette of the advantages is the lifespan of organic materials, susceptibility to environmental factors, as well as greater consumption of LCD screens when displaying white and bright elements. Blue led OLED may end up after CA. 5000h.