Advanced Silicon Group

Nanotechnology for the next generation of solar PV, biosensors & batteries

About the Technology

 

ASG’s core technology is the texturing of silicon using metal enhanced etching to produce silicon nanowire arrays.  ASG owns the IP for practical solar cell device structures with this type of surface and also owns the IP for silicon nanowires used in Li-ion batteries, microfluidics, lab-on-chip, thermoelectrics, MEMS, and sensors.  The unique capabilities of this technology are the controllability of the height, diameter, and density of the nanowires, uniformity over large surfaces, reproducibility, and production via large scale, low cost industrial processes (wet chemistry at atmospheric pressure).

IP Portfolio
ASG owns an extensive family of IP in the field of silicon nanowires and their application

Application in Solar PV

In solar photovoltaics, the process can be implemented using tools found in standard solar cell lines and can produce gains of 0.5% to 1.5% in absolute efficiency over baseline processes.  This means no new capital is needed so there is only a modest upfront engineering cost in implementing the process.  The cost at the cell level is estimated to be the same as standard cells on a $/Wp basis which means that costs are lowered at the module level and further downstream.  The higher efficiency also means cells and modules are worth more.  Perhaps most important today, our process can successfully texture multicrystalline wafers sawn with diamond wire, enabling the  material and cost savings available from this improved technology.  The combination of these effects will raise margins substantially for cell makers (we estimate approximate doubling). 

nanowire vs traditional solar cell

nanowire vs traditional solar cell

Application in Biosensors

 Nanowires have been shown to be highly sensitive detectors of biomarkers, but traditional processes for fabrication are expensive and produce devices with only a handful of nanowires to accomplish the detection.  ASG can produce devices with millions of nanowires inexpensively providing the opportunity for both highly sensitive detection and detection of multiple biomarkers on the same chip.  ASG recently was awarded an NSF Small Business Technology Transfer (STTR) award to apply the technology for the detection of lung cancer biomarkers from blood samples which could result in major cost savings and improvements in patient outcomes.
 

Application in Li-ion Batteries

 ​Silicon is the anode material that has the highest lithium ion absorption capacity. However, silicon expands and contracts 4X when absorbing deabsorbing lithium. In bulk silicon this results in the silicon turning into powder and the battery failing.  Putting silicon in the nanowire form allows this expansion and contraction while maintaining a continuous conductive path down the nanowire .

ASG Patents

 U.S. Patent No. 8,450,599 Nanostructured devices

U.S. Patent No. 8,143,143 Process for fabricating nanowire arrays

U.S. Patent No. 7,973,995 Designing the host of nano-structured optoelectronic devices to improve performance

U.S. Patent No. 8,734,659 Process for structuring silicon

U.S. Patent No. 8,829,485 Selective emitter nanowire array and methods of making same

U.S. Patent No. 8,791,449 Nanostructured silicon for battery anodes

U.S. Patent No. 8,945,794 Process for forming silver films on silicon

U.S. Patent No. 8,852,981 Electrical contacts to nanostructured areas

U.S. Patent No. 9,099,583 Nanowire device with alumina passivation layer and methods of making same

U.S. Patent No. 9,136,410 Selective emitter nanowire array and methods of making same

U.S. Patent No. 9,202,868 Process for fabricating nanowire arrays

U.S. Patent Application No. 14-924,273 Process for fabricating silicon nanostructures -allowed

U.S. Patent No. 9,768,331 Screen printing electrical contacts to nanowire areas

U.S. Patent No. 9,601,640 Electrical contacts to nanostructured areas

U.S. Patent No. 9,783,895 Double-etch nanowire process

U.S. Patent No. 9,449,855 Double-etch nanowire process

U.S. Patent Application No. 13-902,332 Nanostructured devices

U.S. Patent Application No. 15-622,422 Screen printing electrical contacts to nanostructured areas

U.S. Patent Application No. 14-758,091 Metal backed nanowire arrays

U.S. Patent Application No. 15-441,744 Necklaces of silicon nanowires

U.S. Patent Application No. 14-917,698 Metal-assisted etch combined with regularizing etch