New quantum dot white LED luminous efficiency hits record

Turkish scientists have manufactured white LEDs based on nanomaterials.

According to a recent report from the American Daily Science website, Turkish scientists have developed a new type of white light-emitting diode (LED) with a luminous efficiency of a record 105 lumens / watt. The researchers said that with further development, the efficiency of this LED can reach more than 200 lumens / watt, is expected to show their talents in the field of homes, offices, etc., to achieve more energy-saving and environmentally friendly lighting.

The new LED is manufactured using a commercially available blue LED combined with a flexible lens filled with a solution of nano-semiconductor particles called quantum dots. The light emitted by the blue LED causes the quantum dots to emit green and red light. It combines with blue light to produce high-quality white light with precise color temperature and optical characteristics.

The researchers explained that quantum dots have many advantages in the manufacture of white LEDs: they are easy to manufacture; they can change their light emission color by increasing the size of semiconductor particles; and changing the concentration of doped quantum dots can control the characteristics of light.

In order to manufacture such LEDs, quantum dots that can efficiently convert blue light into red or green light are needed. To this end, they carried out more than 300 synthesis reactions and obtained quantum dots that can emit different colors of light and perform best. They mixed cadmium, selenium, zinc, and sulfur at a high temperature to make a quantum dot solution, which filled the gap between the lens made of silicone resin and the LED chip. Silicone lenses are elastic, so no leakage occurs when the solution is injected, and the transparency of the material ensures that the necessary light can pass through.

At present, researchers are working to improve the efficiency of LEDs and hope to use environmentally friendly cadmium-free and lead-free materials. They also plan to study liquid LEDs under different conditions to ensure their long-term stable use.

The head of research, Saidat Nizamoglu of the University of Cork, said: "The efficiency of new LEDs is higher than other white LEDs based on quantum dots. Moreover, the methods of manufacturing quantum dots and synthesizing new LEDs are simple and cheap. It is suitable for large-scale production. If LEDs with an efficiency of 200 lumens / watt can be used to replace traditional lighting sources, the global lighting power consumption will be reduced by more than half, and 200 million tons of greenhouse gas emissions can be reduced. "(Reporter Liu Xia)