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, gl? (www.glo.se) 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).
Iillumination is a major consuming application of electric power around the world. Through the development of high performance light emitting nanowire LED technology, gl? 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.
With over ten years of experience in working with these III-V materials at a nanoscale level, gl? possesses proprietary knowledge, relevant intellectual property and unique experience to bring to bear in solving these unique challenges. gl? 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.
gl? 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 commercialise 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. The company anticipates 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.