glo AB, a Lund University spin-off developing nanowire LEDs, is set to begin pilot production at DTU Danchip and establish a unit in Silicon Valley. Production at the DTU Danchip cleanroom in Lyngby, Denmark, will begin in May 2010. It is a facility where Glo will prepare its first product for full-scale production, but it will also be used for developing new products in the future.
Glo Nanowire LED
Image credit: Glo AB
Glo aims to develop and commercialize energy efficient, low cost nanowire light-emitting diodes (nLED) based on heterostructured semiconductor nanowire epitaxial growth.
Parallel to the pilot production in Lyngby, Glo is establishing a unit in Silicon Valley aiming to develop the technology necessary to scale up production. In total, Glo plans to grow to 30 employees, placed in Lund, Lyngby and Silicon Valley. Bo Pedersen hopes to have a product ready for the market by 2011.
Founded in 2005, glō AB is a venture-backed, development-stage company focused on development and commercialisation of entirely new, highly energy efficient and very low cost nanowire light-emitting diodes (nLED) based on its proprietary heterostructured semiconductor nanowire epitaxial growth and process technologies.
glō employs novel, cutting-edge semiconductor nanotechnology to dramatically lower production cost at the die level of Ultra-High-Brightness (UHB) light emitting diodes (LEDs). A novel type of LED-chip – each with millions of nanowire LEDs or nLED – is expected to offer all the advantages of state-of-the-art conventional planar UHB-LEDs, including high lighting efficiency with very low energy consumption, long lifetime and good functionality, but at radically lower manufacturing costs. This is expected to open the door to solid state lighting (SSL) for general illumination markets worldwide.
Nanowires, which do not exist in nature, are defined as structures with diameters in the range of tens of nanometers and lengths in the order of nanometers to micrometers. In practice, nanowires are usually symmetric in the two smaller dimensions with a round or polyhedral cross-section. The most controlled way to fabricate these nanowires is via AU metal particle assisted epitaxial growth. As the growth front of the wire is defined by the interface between the top plane of the wire and the bottom of the Au particle, the growing wire lifts the particle. The diameter of the wire is mainly determined by the diameter of the Au particle.
Today, glō routinely grows nanowires several micrometers in length and with only 5–200 nm in diameter. Since the end of the 1990s, the nanowire research field has significantly expanded worldwide. To date nanowires have been grown in most III–V materials combinations and with several epitaxial techniques, e.g. MOVPE (metal organic vapor phase epitaxy), CBE (chemical beam epitaxy), and MBE (molecular beam epitaxy). Even growth methods without metal seed particles have been developed, using selective-area growth (SAG).
illumination is a major consuming application of electric power around the world. Through the development of high performance light emitting nanowire LED technology, glō intends to foster low cost, new products that dramatically reduce the energy consumed by artificial light sources while providing quality illumination in terms of brightness and color rendering. Play Video.
The specific materials that underlie the Company’s nLED technology are quite similar to those that can convert sunlight into electrical energy. The science of photovoltaics involves configuring materials that react to the energy contained in sunlight, generating the flow of electric power.
Examples of complex epitaxial nanowire structures grown in Lund. (a) GaP nanotrees; (b) axial InAs/InP double-barrier heterostructure; (c) InAs nanowires grown by CBE; (d) from the side, (e) from the top.
Image credit: glo AB
With over ten years of experience in working with these III-V materials at a nanoscale level, glō possesses proprietary knowledge, relevant intellectual property and unique experience to bring to bear in solving these unique challenges. glō has been created to apply this knowledge and experience directly to the challenge of breaking the current barriers encountered in solid state lighting, and a sister company, Sol Voltaics AB is addressing the same frontiers in photovoltaics.
Glō has developed technologies to fabricate perfect one-dimensional crystalline semiconductor structures (nanowires), and complex structures composed of nanowire-trees , with direct control of morphology and chemical composition, including atomically-sharp heterostructures.
Such nanowires hold great promise as light emitting diodes because (1) they are produced to a large extent with self-assembly techniques, providing complex structures with relatively simple processing, (2) the limited radial extent of the nanowires allows heteroepitaxial combination of materials with virtually no regard to lattice matching or thermal expansion issues, thus avoiding the strains and defects in conventional planar LEDs that plague both efficiency and manufacturing yields, (3) the vertical form factor of the nanowire itself promotes efficient light extraction, and (4) nLED can be grown directly on large area (6” or even bigger) silicon wafers with mass-manufacturing techniques already in common use, thus avoiding the high cost of small (2” – 4”), expensive wafers (such as sapphire, SiC and GaN) uniformly used by the LED industry today.
Together, these advantages will permit simple growth of complex networks of optically active heterostructured materials with monolithically integrated electronic devices on inexpensive mono and poly-crystalline Si substrates.
The Company’s goal is to develop and commercialize highly efficient multiple heterostructure nanowire based light emitting diode chips fabricated on readily available low-cost and large area silicon wafers using enhanced, lower cost epitaxial growth processes that are readily scalable to mass production. We anticipate developing and offering nanowire-based LED chips to the market with high efficacy but at a cost far below today’s state-of-the-art planar LEDs, while opening the door to even higher future potential efficiencies and lower costs.
Contacts and sources:
CEO Bo Pedersen.