The bad news is that another innovative California-based solar tech firm has gone out of business. The good news is that the firm's innovative technology lives on, and could well prove important in accelerating the state's solar revolution. Nashua, NH-based GT Advanced Technologies announced today that it had acquired core intellectual property of San Jose startup Twin Creeks, which had developed a way to increase the amount of solar panel made from a unit of silicon crystals by a factor of ten.
GT acquired Twin Creeks' technology for $10 million, a surprisingly low sum for the core intellectual property of what had been a much-lauded startup.
Silicon crystals must be shaved into slices for use in photovoltaic panels. A typical slice is about 200 microns thick -- about the thickness of an index card. In March, Twin Creeks announced that it had developed a way to make silicon wafers one tenth that thickness, or 20 microns.
Twin Creek's "Hyperion" Technology uses a beam of protons aimed at a flat surface of a chunk of crystalline silicon. The protons penetrate into the crystal to a depth of twenty microns. The material is heated, and the layer of protons -- which can also be thought of as hydrogen ions -- form a weak layer in the crystal. The 20 micron layer above that weak layer exfoliates from the block, and can be finished for use in a PV panel.
Conventional wafer creation technology involves cutting with a wire saw, which necessarily creates a lot of waste -- sawdust, or "kerf." The Hyperion technology reduces that waste, and provides as much as ten times the usable wafer surface area per unit of silicon crystal, offering the prospect of significantly cheaper silicon-based PV.
It's a fascinating and promising technology, but it wasn't enough to save Twin Creeks from the ravages of its lenders. According to Ucilia Wang at GigaOm, the firm had hoped to adapt to the bottoming-out of the market due to dropping solar cell prices by shifting from selling PV panels to selling the technology to make those panels more cheaply and efficiently. It looks as though GT will be the benefactor of that strategy: the company plans to implement Hyperion's proton-induced exfoliation in a number of applications.