More accurate measurement of ultraviolet rays may now be possible with the development in Britain of a new photodiode detector.

UV radiation is the most energetic form of optical radiation and exposure to it is potentially hazardous. Accurate measurement of the LTV radiations from the sun has been made difficult by the presence of significantly large amounts of visible and infrared radiation.

Optical radiation is detected by a photodiode when an electron is excited across an energy gap. The new detector uses silicon carbide whose energy gap is such that only the UVrays have enough energy to excite an electron across the gap, say researchers.