But until now the production costs have been too expensive for widespread use in homes and offices - a single bulb would have cost £20. However, the researchers have found a cheaper technique to help manufacture the bulbs and manufacturers have begun work on production prototypes. The first units could hit shelves within two years. Professor Colin Humphrey, head of the centre, said: "This could well be the holy grail in terms of providing our lighting needs for the future."
The bulbs are 12 times more efficient that conventional tungsten bulbs and three times more efficient than compact fluorescent "energy efficient" bulbs. They can burn for 100,000 hours and they illuminate instantly and can be dimmed, unlike energy efficient bulbs. If they were installed in every home and office the bulbs could cut the proportion of