Category 18 April 2019

Novel solutions for LED lighting through nano-substitution

Ecospark AB provides a planar light source technology that allows for large area white light sources at a lower cost per lumen to the global lighting industry. The technology is based on ZnO nanowires grown with a wet chemical method at low temperature. The technology is a spinout from Linköping university.

The challenge

As a contribution to increased energy efficiency in buildings, the EU has decided to phase out less efficient light sources through regulations such as EG 244/2009 and EG 859/2009. Certain lighting technologies may no longer be sold commercially and incandescent lamps have been removed from the store shelves. Low energy lamps and LEDs (Light Emitting Diodes) have been viewed as promising alternatives for substituting the old light bulbs, but are in fact facing some new challenges. The low energy lamps are energy efficient but contain mercury which is a significant environmental hazard. LEDs give poor quality white light and are relatively expensive.

The innovation

The company Ecospark AB uses new technology to develop LED lighting products for large areas. Their novel approach uses an innovative LED structure based on the semiconductor material zinc oxide (ZnO) in combination with advanced nanowire technology to produce LED-chips and large LED panels.

LED-chips are what actually generate light in an LED-bulb, and conventional LED-chips available on the market are exclusively based on gallium nitride (GaN). Due to GaN’s properties, traditional manufacturing of LED-chips requires temperature of 1000⁰C.  ZnO shares many of the desirable properties of GaN, both being high bandgap materials and thus attractive for LED and laser production. By substituting GaN with the less expensive semiconductor ZnO, Ecospark’s proprietary LED structure can be produced in low temperature manufacturing processes lowering production costs and the product’s environmental footprint.  

For lighting needs that require large-format illumination sources, large LED panels can be manufactured on large flexible substrates and glass. However, conventional GaN technology doesn’t allow production of such large panels due to material limitations. Ecospark’s ZnO-based, large panels can compete with OLEDs (Organic Light-Emitting Diods) in term of efficiency, intensity and quality of white light, but to a fraction of the cost.

Why did it work?

The innovation was developed based on the extensive research into zinc oxide (ZnO) by one of the co-founders of the company, leading to the establishment of the privately held company Ecospark AB in 2003, which is now based in Norrköping, Sweden. Since the start, about €7,9 million of equity and governmental R&D grants (such as public grant partial funding for R&D) supported the company’s progress. The technology is now considered a 5 on the TRL scale.

Further deployment

The future development plans of the company include industrialization of the ZnO research, which would require additional capital for product and market development. Ecospark estimates that the potential market for the planar LED-panels will be €5 billion by the year 2020. The new ZnO nanowire technology from Ecospark will have other applications in life science and bioscience, solar cells, cancer treatment and more.