24 November 2010

SETI’s UVTOP DUV LEDs pass environmental robustness tests to complete space qualification

Deep ultraviolet (UV) LED maker Sensor Electronic Technology Inc (SETI) of Columbia, SC, USA, together with Stanford University and National Security Technologies (NSTec) of Livermore, CA, has demonstrated what is claimed to be unprecedented environmental robustness and radiation hardness of its UVTOP deep ultraviolet LEDs.

Deep UV LEDs with peak emission wavelength of 255nm have passed stringent space qualifications for large temperature variations and mechanical shocks, with 27 cycles of 100K temperature cycles and 14g rms random mechanical vibrations. The forward voltage, emission spectra, and optical output power exhibited no significant changes after these harsh environmental tests.

The UVTOP LEDs have been successfully tested against the requirements for deep space exploration such as the Europa Jupiter System Mission (EJSM), where they will be subject not only to severe thermal and mechanical shocks but also high levels of radiation. Under irradiation up to 2x1012 protons/cm2, the LEDs demonstrated extreme radiation hardness. UV LEDs have so far have exhibited high operational lifetimes in excess of 26,000 hours in nitrogen atmosphere and 25,000 hours in vacuum, without significant power drop or spectral shift.

SETI says that the extreme testing demonstrates that the optical, electrical and mechanical robustness of the UVTOP LEDs is suitable for many space and terrestrial applications where conventional UV light sources are too fragile.

In addition, solar-blind P-i-N photodiodes with a peak responsivity matching the UVTOP LEDs at 255nm were also manufactured by SETI and tested to the same stringent space qualifications. These detectors also exhibited extreme radiation hardness and retained 50% responsivity up to 3x1012 protons/cm2 fluence, says the firm.

Tags: Sensor Electronic Technology UV LEDs

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