Nanotechnology is basically the manipulation of a matter or various matters on a molecular scale. The technology theory has been heralded since the 1960s, but the main research and development began during the 1980s. Its introduction to LED production is bringing quality achievements in both lighting solutions and displays.
LEDs are the most energy-efficient lighting solution on the market, converting most of the energy into light. Still, about 20% of the light emitted by the diode is lost due to the high refractive index of LEDs (a certain percentage of the light is reflected back into the diode and ultimately not emitted). This rate generally depends on the components of the diode. In order for this light to be lost inside the diode, the researchers, and recently adopted by manufacturers, used nanotechnology and created microscopic holes (approximately 400 times narrower than a human hair) in the surface of the diode, typically hundreds of thousands of holes in a single diode.
Since the introduction of Nano printing technology to this process, the creation of LEDs with nanotechnology is cheaper and much faster compared to previous solutions. The so-called Nano LED is a more powerful and efficient LED solution, with a definitely lighter emission. Also, in addition to reducing optical loss, the recovered light leads to less heat building up inside the diode. In this way, the LEDs can be packed closer to each other and also have a generally longer lifespan. Another added benefit of Nano-LEDs is their high CRI and wider color temperature range.
One of the first applications of the technology was not even in lighting solutions, but in television screens, where nanotechnology resulted in a new generation of LED televisions. The first LED TVs are not real LED solutions, they are actually LCD TVs with LED backlighting from the sides. With nanotechnology, LED TVs are created with a full array of LEDs, behind a panel of microscopic or nano dots that let through the light emitted by the LEDs. In this way, the light is scattered more evenly, giving the displayed image more definition, clarity and softness. This technology also allows the screen to be thinner: the first TV made with the technology is the LG LEX8, which is only 0.88 cm thick.
Nanotechnology regularly brings new and exciting results. In the field of lighting, one of the latest developments are “nano-LEDs” that grow like cables. This technology was accidentally discovered in September 2010, when chemists Babak Nikoobakht and Andrew Herzing experimented with horizontally growing nanowires. With the increasing thickness of the gold catalyst, the nanowires developed a “nanowall”, through which electrons can flow. Charged with electricity, the wires produced light, for which the researchers called the phenomenon “nano-LEDs.” This technology will allow lighting to be added to microscopic solutions, but its full scale of potential has yet to be discovered.
An equally interesting achievement of nanotechnology in lighting could be the solutions of Academia Sinica and National Cheng Kung University in Taiwan, where professors implanted gold nanoparticles in tree leaves, thus creating bioluminescent red light. These bio-LEDs need further development, but the goal is to create trees that provide street lighting along roadways. Presumably the trees would also absorb CO2 at night, which is an additional level of photosynthesis.
Nanotechnology used to create more lighting solutions is a promising future in less conventional forms of lighting. Biological lighting or organic lighting are key prospects in green lighting, making research into lower-cost, better-performing LEDs crucial.