Carbon nanotube-based lights are more efficient than LEDs

Japanese scientists have recently discovered carbon nanotube-based lights that are more efficient than LEDs.

Scientists from Tohoku University in Japan have developed a new type of energy-efficient flat light source based on carbon nanotubes with very low power consumption of around 0.1 Watt for every hour's operation about a hundred times lower than that of an LED.

Norihiro Shimoi, an associate professor of environmental studies at the Tohoku University, said that the simple 'diode' panel could obtain high brightness efficiency of 60 Lumen per Watt, which holds excellent potential for a lighting device with low power consumption.

Considering the major step for device manufacture, the wet coating process was a low-cost but stable process to fabricate large-area and uniformly thin films, the flat-plane emission device has the potential to provide a new approach to lighting in people's life style and reduce carbon dioxide emissions on the earth, he further added.

The new devices have luminescence systems that function more like cathode ray tubes, with carbon nanotubes acting as cathodes, and a phosphor screen in a vacuum cavity acting as the anode. Under a strong electric field, the cathode emits tight, high-speed beams of electrons through its sharp nanotube tips, a phenomenon called field emission. The electrons then fly through the vacuum in the cavity, and hit the phosphor screen into glowing.

In recent years, carbon nanotubes have emerged as a promising material of electron field emitters, owing to their nano-scale needle shape and extraordinary properties of chemical stability, thermal conductivity and mechanical strength.

The study is published in the journal Review of Scientific Instruments, from AIP publishing.