LETI spin-off company secures funding for LED-on-microwire development

April 17, 2013 // By Peter Clarke
Aledia SA (Grenoble, France), a startup developer of light-emitting diodes (LEDs) on microwires of gallium-nitride-on-silicon has made its first LEDs on 200-mm diameter wafers and raised €10million in a first round of venture capital finance.

The 3-D GaN-on-Silicon microwire technology was developed over a six-year period at the LETI research institute in Grenoble and the claim is that Aledia's LEDs will have a production cost of one quarter that of conventional planar LEDs.

Aledia's technology uses millions of sub-micron diameter light-emitting GaN pillars standing up from the silicon surface to obtain an improved area efficiency of light generation. This produces three times more light per square millimeter of planar area, the company claims.

In addition, little material is used to form the microwires, approximately two-thirds of the material cost in planar LEDs and this, added to 200-mm wafer processing should produce the 25% cost base, the company said. A secondary advantage claimed for the technology is that multiple colors can be created on single wafer or even on single die, which should produce advantages for tuning the output for general lighting applications.

A further claimed advantage is that the so-called WireLED devices is that devices suitable for general lighting could be fabricated without the use of phosphors. This is because WireLEDs can be tailored to produce green and red as well as the industry-standard blue GaN LEDs.

Microwire pillars include vertical stacked compound semiconductor layers to provide increased light emission compared with horizontal layers in planar LEDs. Source: Aledia.

The company has been spun out of LETI by the technical developers with Georgio Anania as co-founder, CEO and chairman. Anania was previously CEO of Bookham Ltd., a supplier of optical components which Anania helped take public. Anania's co-founders are Xavier Hugon, COO, and Philippe Gilet, CTO.

Aledia raised €10 million with Braemar Energy Ventures, Sofinnova Partners, Demeter Partners and CEA Investissement participating.

"Since our financing last year, we have scaled up our microwire manufacturing process and transferred it to 8-inch silicon wafers. We can now push forward to optimise the performance of these products and bring them to market," said Anania, in a statement.

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