Nobel laureate Hiroshi Amano says Gallium Nitride is the material to watch out for as devices based on it will play a big role in Internet of Things (IoT), 5G communications and Internet of Energy (IoE), including wireless powering of devices over several metres.
Gallium Nitride-based ultraviolet technology has already helped in water purification, said Amano. For his pathbreaking work on fabricating Gallium Nitride LED, which led to the creation and explosion of the application of LED sources, Amano, and colleagues, Isamu Akasaki and Shuji Nakamura, shared the Nobel Prize for Physics in 2014.
The 57-year-old Japanese physicist enthralled a gathering of students, staff and audience at the University of Hyderabad (UoH), during a lecture on ‘Blue LEDs and Transformative Electronics for Developing Sustainable Smart Society’. It was held as part of the Hyderabad Lecture Series, sponsored by the Insurance Regulatory and Development Authority of India (IRDAI).
The Japanese trio’s work broke new ground in creating blue Light Emitting Diodes (LEDs). The invention paved the way for the development of bright and energy-saving white light sources. It showed methods of creating long-lasting and efficient alternatives to traditional light sources, such as the incandescent light bulbs that dominated the 20th century.
Challenges ahead The future challenge, says Amano, is to develop technologies that are more cost-effective. The white LED, which using the Gallium Nitride technology, has revolutionised display and energy efficiencies. In future it can meet the needs of smart and sustainable technologies. In an interactive session, Amano lucidly explained the latest technology in fabrication of small and efficient LEDs for display applications.
The LED lamp holds promise for increasing the quality of life for over 1.5 billion people around the world, who lack access to electricity grids. This is possible due to its low power requirements, which can easily be powered by cheap, local solar power, according to Amano. The invention of the efficient blue LED is just 20 years old, but it has already contributed to the creation of white light in an entirely new manner.
White LED lamps are constantly improving and getting more efficient. Materials consumption has also diminished as LEDs last up to 100,000 hours, compared to 1,000 hours for incandescent bulbs and 10,000 hours for fluorescent lights.
Starting as an undergraduate student in 1982 with I Akasaki, Amano went on to pursueresearch in characterisation and device applications of group III nitride semiconductors, well known materials used in blue LEDs. His lab was came to be known as ‘No night Castle’, for it was always lit late into the night even during weekends and holidays.
In 1985 he developed low-temperature deposited buffer layers for the growth of group III nitride semiconductor films on a sapphire substrate, which led to the realisation of group-III-nitride semiconductor-based LEDs and laser diodes.
In 1989 he succeeded in growing p-type GaN and fabricating a p-n-junction-type GaN-based UV/blue light-emitting diode for the first time in the world.
The lecture was presided over by Appa Rao Podile, Vice-Chancellor of the UoH. IRDAI had given a corpus fund to the university in 2013 to organise the annual lecture series.