Science and Technology
In News Researchers in Bengaluru’s Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), an autonomous institute under DST, have shown for the first time infrared light emission and absorption with GaN nanostructures.
GaN nanostructures:
- It is a widely used material for blue light emission like Blue LEDs
- It is one of the most advanced semiconductors.
- It is already used in visible and ultraviolet light with LEDs and laser diodes
- Now, for the first time a new method to confine and absorb infrared (IR) light with GaN nanostructures has been developed.
Technology used:
- A scientific phenomenon called surface polariton excitations in GaN nanostructures leads to light-matter interactions at IR spectral range.
- Surface polaritons are special modes of electromagnetic waves traveling at the interface of a conductor and an insulator such as air.
- By altering the morphology and shape of the nanostructures, they are also able to excite plasmon polaritons in GaN, which results in extending the light-matter coupling to further reaches of the electromagnetic spectrum.
- Surface polaritons are quasi-particles which have both light and matter characteristics.
- To grow these GaN nanostructures, the researchers utilized a specialized material deposition instrument called molecular beam epitaxy.
- This instrument uses ultra-high vacuum, like the conditions of outer space.
- This instrument grows high-quality material nanostructures with dimensions about 100000 times smaller than the width of a human hair.
Applications:
- It can help develop highly efficient infrared absorbers, emitters, and modulators that are useful in defense technologies, energy technologies, imaging, sensing, and so on.
- Polaritonic technologies have attracted a wide range of applications, such as secure high-speed light-based communication (LiFi), next-generation light sources, solar energy converters, quantum computers, and waste-heat converters.
- In the last 25 years, blue LED with GaN has changed our world significantly.
- The infrared surface polariton excitations can be translated to many other semiconductors as well.
Source: PIB
Previous Year Questions
Q.1) With reference to carbon nanotubes, consider the following statements: (2020)
- They can be used as carriers of drugs and antigens in the human body.
- They can be made into artificial blood capillaries for an injured part of human body.
- They can be used in biochemical sensors.
- Carbon nanotubes are biodegradable.
Which of the statements given above are correct?
- 1 and 2 only
- 2, 3 and 4 only
- 1,3 and 4 only
- 1,2,3 and 4
