In a feat comparable to the fable of blind man who carried a lame man on his back, lending him his feet and borrowing from him his eyes, researchers at the Indian Institute of Science (IISc) Bangalore have combined light emitting but poor conductor quantum dots with good conductor, but non-light emitting graphene to produce a novel hybrid that could revolutionize the next gen mobile and television displays.
Quantum dot semiconductor nano-crystals absorb Ultraviolet light and produce sharp, bright colours. But, they are poor electrical conductors. They are, therefore, are suitable to make devices that convert light into electricity. Graphene, on the other hand, are very thin two-dimensional material and are almost transparent to light. They emit radiation very faintly. But, they are excellent electrical conductors.
When hybrids are formed by combining the two, normally energy generated from incident light in a quantum dot is swiftly pulled away and absorbed by graphene and converted into electrical signals. They can, therefore, be used to develop high efficiency and sensitive sensors or photo detectors.
However, what is good for photo detectors is bad for fabrication of display devices. Graphene acts like a sponge inhibits quantum dots from emitting light by taking away the energy says senior author Jaydeep Kumar Basu, Professor, Department of Physics, IISc. Without emission of light there is no display device.
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Source: Business Line