Versatilis gets US Patent for Semiconductor 'Dust'
Versatilis, a Vermont based company that focuses on novel materials and processes, has been issued a US patent that shows how fine semiconductor waste particles can be rapidly deposited as a closely packed monolayer and then further processed into a sea of low cost solar cells or micro-LEDs.
"By levering cheap, ex-situ produced and optimised, single or polycrystalline powders and fines for Si, Ge, CIGS, GaN, ZnO as the starting raw material and wrapping unique processing techniques around that, we can produce highly functional opto-electronic devices with reduced infrastructure, processing, and material utilisation cost," stated Ajay Jain, Versatilis CTO and inventor of the now technology, US Patent No. 8,859,310.
The active layer in a solar cell or the light-emitting layer in a LED, is the most costly and capital-intensive part of the manufacturing process, since it must be made to high standards of semiconductor crystal quality and uniformity. Versatilis, however, has shown that the active layer can be made from semiconductor fines or powders of single crystal particles densely packed into a monolayer, in a configuration not unlike sandpaper one particle thick, and then further processed into active diode structures serving as solar cells, for example, or as LEDs.
Such particles are readily available, often a byproduct of other processes or made inexpensively off-line, or sometimes chemically synthesised. Silicon fines, for example, are widely available, screened for a desired size distribution, as are CIGS and GaN particles, the latter chemically synthesised. And a small amount of such 'dust' can go a long way; for example, a kilogram of one micron single crystal CIGS particles used as micro-solar cells can cover an area over 300 square meters, resulting in very low costs per unit area.
The potential cost savings have led others to try using semiconductor particles in a variety of ways, however, none have proven commercially practical. A major challenge has been to lay down these particles quickly enough and as a monolayer. Similarly, researchers have shown basic functional devices with nanorods, nanowires and other semiconductor 'nanostructures' in the lab, only to be stopped by a general lack of production ready manufacturing technology for nanoscale, including suitable tools for in-line process metrology and characterization.
In addition to processing semiconductor particles into useful devices, Versatilis has unique fluidics technology for rapidly depositing such particles as a monolayer, from nano to microscale, on wafers or in a continuous, high-speed web. It had licensed the technology to VersufleX Technologies, which is beginning to sell benchtop process tools to R&D labs based on this technology.
"This technology will not set performance records for efficiency in PV cells nor in lumens/watt for LEDs, but we believe there is no cheaper, more practical way to realize semiconductor diode based functionality over a large, flexible area," added George Powch, CEO, "We think it can enable low cost building of integrated photovoltaics or rival OLEDs with a wholly inorganic large area micro-LED solution."
Versatilis LLC is a Vermont based technology and business development company, commercialises technology through licensing and partnering with others, or setting up separate focused subsidiary companies. Versatilis has won numerous Small Business Innovation Research (SBIR) Awards from US Government Agencies including DOE, DARPA, ONR and ARL, and is a member of the iCLEAN /E2TAC Incubator at Albany's College of Nanoscale Science and Engineering.
