Light Emitting Diode

LED light bulbs were introduced in 1870, revolutionizing the lighting industry with their energy efficiency and long lifespan.

In 1907, the first light-emitting diode (LED) was invented. LEDs are semiconductor devices that produce light through electroluminescence, where electrons recombine with electron holes to emit photons.

In 1921, Russian physicist Oleg Losev observed the 'Round effect' of light emission, which was later outlined in 16 papers from 1924 to 1930, contributing to the development of LEDs and their applications.

LED (Light-emitting diode) lighting was actually created in 1927, contrary to the common belief that it is a 21st century invention. LED technology has been evolving since then with the contribution of many individuals.

In 1928, Losov detailed the I-V characteristics of a carborundum diode and observed the onset of light emission, leading to the understanding that the emission was not a thermal effect but a result of semiconductor action.

French Physicist Georges Destriau discovered light emission in zinc sulfide in 1935, and is credited as the inventor of electroluminescence.

Hungarian Zoltán Bay and György Szigeti patented a lighting device based on silicon carbide in 1939, with the ability to emit white, yellowish white, or greenish white light depending on impurities present.

In 1951, the idea for the light emitting diode (LED) resurfaced as a result of research into semiconductor diodes. It took several years for the work to reach completion.

In 1958, Egon Loebner and Rubin Braunstein created the first green LED, marking a significant advancement in LED technology.

James R. Biard and Gary Pittman filed a patent titled 'Semiconductor Radiant Diode' in August 1962, describing a zinc-diffused p–n junction LED with efficient emission of infrared light under forward bias. This marked the invention of the first practical LED.

Nick Holonyak demonstrated the first semiconductor laser to emit visible light using gallium phosphide arsenide (GaAsP) at General Electric in Syracuse, New York. The device also functioned as a red light-emitting diode at room temperature.

In 1968, the Monsanto Company produced visible red LEDs on a large scale, becoming the first company to manufacture affordable LEDs.

Hewlett-Packard introduced the HP Model 5082-7000 Numeric Indicator, the first LED device to use integrated circuit technology, revolutionizing digital display technology.

In 1971, Edward Miller and Jacques Pankove successfully created the first blue LED, expanding the color range of LEDs and opening up new possibilities for lighting and display technologies.

The first blue-violet LED using magnesium-doped gallium nitride was created at Stanford University by Herb Maruska and Wally Rhines, leading to the basis for all commercial blue LEDs and laser diodes.

T. P. Pearsall designed the first high-brightness, high-efficiency LEDs specifically adapted to optical fiber telecommunications by inventing new semiconductor materials.

In 1986, Herbert Maruska and Walden C. Rhines from Stafford University created a working blue LED using Magnesium, setting future standards.

The development of high brightness LEDs marked a significant advancement in LED technology, allowing for applications beyond simple indicator lamps. Hewlett Packard's AlGaAs diodes produced in 1987 were bright enough for use in lighting applications, particularly in the automotive industry for brake lights and traffic lights.

The U.S. Department of Energy encouraged the development of white LED technology to provide cost-efficient lighting solutions for business owners. Today's LED lights are significantly more efficient than traditional incandescent bulbs, consuming 80 percent less energy and lasting 25 times longer.

Theodore Moustakas patented a method for producing high-brightness blue LEDs using a new two-step process, contributing to the advancement of LED technology.

Physicists Isamu Akaski and Hiroshi Amano developed a high-quality Gallium Nitride for blue LEDs in 1993.

In 1994, Shuji Nakamura invented ultra-bright blue LEDs using Gallium Nitride, followed by high-intensity blue and green LEDs using Indium Gallium Nitride. This innovation laid the foundation for cost-efficient white LED lights.

In 1995, LEDs were officially launched, paving the way for their widespread adoption in various lighting and display technologies.

Wafer-level packaged white LEDs were introduced in 1998, allowing for the production of extremely small LEDs. The size of an LED die is limited by the temperature of the phosphor during operation and how it is applied.

Around 2002, white LEDs designed for residential lighting became commercially accessible, although initially expensive at approximately $100 per bulb.

In 2004, the Edgewood Chemical Biological Center initiated the effort to create a biological detector named TAC-BIO, incorporating UV light-emitting diodes for light-induced fluorescence sensors used for biological agent detection.

Shuji Nakamura received the Millennium Technology Prize in 2006 for his contribution to the development of white LEDs, which revolutionized lighting technology.

In 2007, scientists identified Auger recombination as the mechanism causing efficiency droop in LEDs, debunking the earlier suspicion that elevated temperatures were the root cause.

In 2008, the US Department of Energy created the L Prize competition to encourage the shift to LED lamps and other high-efficiency lighting. The Philips Lighting North America LED bulb won the first competition on August 3, 2011, after completing intensive testing.

High-power LEDs can be driven at currents from hundreds of mA to more than an ampere, emitting over a thousand lumens. They require heat sinks for heat dissipation to prevent overheating.

In 2010, the DesignLights Consortium introduced the first Qualified Product List (QPL) to certify LED products meeting industry standards, marking a significant step towards the viability of LED lighting for widespread use.

In 2011, Phillips won the L-Prize competition organized by the United States Department of Energy for developing high-quality, high-efficiency solid-state lighting products to replace incandescent light bulbs. They were awarded a $10 million cash prize for their LED lamp replacement for the 60-watt incandescent bulb.

In January 2012, Osram demonstrated high-power InGaN LEDs grown on silicon substrates commercially, marking a significant advancement in LED technology.

In 2014, Shuji Nakamura, Hiroshi Amano, and Isamu Akasaki were awarded the Nobel Prize in Physics for the invention of efficient blue light-emitting diodes, which revolutionized LED lighting.

By 2015, the majority of lighting retrofit work at EMC shifted to LED products. The projects were almost 100% LED a year later.

In 2018, perovskite LEDs (PLEDs) emerged as a new family of LEDs based on semiconductors called perovskites, showing potential for cost-effectiveness and high efficiency by eliminating non-radiative losses.

On September 20, 2021, the team led by Sargent et.al from the University of Toronto published their research findings in the Journal of the American Chemical Society (JACS) on bright and stable light-emitting diodes (LEDs) based on perovskite quantum dots within a perovskite matrix. The research reported that perovskite quantum dots remain stable in a precursor solution thin film of perovskite and drive the uniform crystallization of the perovskite matrix using strain quantum dots as nucleation centers.

Jiang et al. strategically incorporated large cations to enhance the efficiency of red light perovskite LEDs by controlling the phase distribution of quasi-2D perovskite materials. This approach led to the development of perovskite LEDs achieving an EQE of 25.8% at 680 nm.

Zhou et al. successfully controlled ion behavior to create highly efficient sky-blue perovskite light-emitting diodes by utilizing a bifunctional passivator. The passivator effectively passivated the deficient lead atom and inhibited the migration of halide ions, resulting in an LED emitting light at a stable wavelength of 483 nm.

Researchers achieved a world-record external quantum efficiency of 30.84% for green PeLEDs by optimizing charge carrier transport and light distribution, resulting in exceptional light output coupling efficiency.

LED technology is still evolving with new developments and inventions, including the advancement of organic LEDs for lighting purposes. LEDs have become a common electronic component used in various circuit designs for indicators and lighting, in both residential and industrial settings.