Sidestepping technical limitations of current planar LED technology
Nanowires are fabricated columnar structures with diameters in the range of tens of nanometers and lengths on the order of hundreds of nanometers to micrometers. By comparison, the diameter of a human hair is about 500 times larger than a 100nm nanowire. Each nanowire acts basically as an individual light-emitting diode (LED). Any color of the visible spectrum, ranging from deep blue to red, can be realized using nanowire LEDs with industry-standard semiconductor material and manufacturing equipment.
Scanning Electron Microscope (SEM) picture of actual glō nanowires
SEM of actual glo Nanowire chip showing individual nanowires (zoom)
True White LED - Monolithic RGB LED Chip (Illustration)
True White LED without Phosphor conversion
glō’s RGB nanowire LEDs (nLEDs) are made using one material system with the active layers grown on the crystallographically-favorable non-polar m-plane. The wavelength shift and efficiency droop that are observed with commercially-available planar LEDs is reduced to a minimum with nLEDs. In the mid-term this will enable a true white RGB (red, green and blue) LED without the need of lossy phosphor conversion, thus achieving the highest CRIs and efficiencies.
glō has developed technologies to fabricate defect-free, single-crystal semiconductor structures, with direct control of morphology and chemical composition. glō’s nanowires are produced with self-assembly techniques, providing complex structures with relatively simple and standard process equipment. The limited radial extent of the nanowires allows hetero-epitaxial combination of materials with virtually no lattice-matching or thermal-expansion issues, thus avoiding the strain and defects characteristic of conventional planar LEDs that limit efficiency, color stability and manufacturing yields. The vertical form factor of the nanowire itself promotes efficient light extraction and it can be grown directly on large area silicon wafers with manufacturing techniques already in common use, thus avoiding the high cost of small wafers such as sapphire, SiC and GaN.
Top View Nanowire SEM
Actual glō nanowire dies - Blue, Cyan, Green, Amber, Red
Blue nLED. Each dot represents a nanowire LED
glō currently holds 50+ patents across US, Europe and Asia. These patents are not subject to any cross-licensing with the LED oligopoly. The patents address nanowire materials, epitaxial growth conditions, substrates and on various device structures and fabrication processes. The patent portfolio, including application-related solutions, continues to grow along with the technical advances made by the glō team.