ICULTA: Far ultra-violet LEDs from Sillanna

Silanna UV will be showing its recently-introduced UVC LEDs at the International Conference on UV LED Technologies & Applications (ICULTA) in Berlin next week.

Its ‘short period superlattice’ (SPSL) die structure has repeating layers of AlN and GaN, and is designed to overcome the limitations of earlier structures.

“Old-fashioned AlGaN-based far UVC LEDs in general suffer from poor carrier injection, low light emission and high drive voltage, due to the inherit limitations of high Al-content AlGaN,” according to Silanna.

Regarding SPSL, it said: “The presence of GaN maintains the TE dominance of the emission as well as lowering the activation energy of donors, resulting in more efficient devices. Furthermore, the emission wavelength can be easily tuned using the thickness of the GaN well, a process that is significantly easier to control than tuning of Al composition in the barrier and well.”

In autumn last year, it announced the 235nm (far-UVC) SF1 series and 255 nm (deep-UVC) SN3 series of SPSL LEDs, both available in either 120° (above image) or 30° (left image) SMD packages.

“The 30° package’s parabolic lens provides greater irradiance than even traditional UV lamps,” claimed the company.

The 235nm peak SF1 parts are suited to water quality nitrate (NO₃) and nitrite (NO₂) detection, CO₂ detection and liquid chromatography.

255nm SN3 types are also used to asses water quality, for ‘UV254’ organic compound sensors, chemical oxygen demand monitoring, and suspended solids measurement – as well as ozone gas detection and in medical analysers.

In January this year, the company added TO-39 can-packaged 235nm and 255nm UVC LEDs with an 18° emission angle.

The gold coated can has a steel header and “the weld between the cap and the header provides hermetic protection to the die, and the ball lens offers a narrow viewing angle for the high irradiance required in most sensing applications”, it said.

Silanna Group is an Australian semiconductor manufacturer established in 2006 – privately funded since being acquired from Peregrine Semiconductor in 2008. Silanna UV is based in Brisbane and is an ISO 9001:2015 manufacturer.

Find the UVC LEDs here, or on Silanna’s stand at ICULTA, 23 – 26 April at Melia Berlin in Germany.