GT’s Recent Solar Cell Development Partnered with New Solar Stacking Techniques is a Ray of Sunshine

Posted: February 27, 2014 by mattmargolis24 in My Publications
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A few days ago I gave everyone a spoiler of GT’s recent solar cell development plans as laid out from their recent patents along with my interpretation of the patent.  I have now found a solar cell stacking method that could revolutionize modern solar day efficiency ratings when used in partnership with GT’s super slim solar cell developments.

A recent article published on 2/22/14 by the economist  details some ground breaking work that has emerged out of the University of Illinois Urbana-Champaign.

 

John Rogers, of the University of Illinois, Urbana-Champaign, is one. The cells he has devised (and which are being made, packaged into panels and deployed in pilot projects by Semprius, a firm based in North Carolina) are indeed better. By themselves, he told this year’s meeting of the American Association for the Advancement of Science, they convert 42.5% of sunlight. Even when surrounded by the paraphernalia of a panel they manage 35%. Suitably tweaked, Dr Rogers reckons, their efficiency could rise to 50%. Their secret is that they are actually not one cell, but four, stacked one on top of another.

 

Below is my previous detail of GT management’s cliff hanger from Monday’s  conference call which relates directly to Hyperion and Solar Cells:

we have a deployed a new technology that we expect will significantly impact the economics of producing solar cells and modules. This technology was developed and comes out of a research operation we established in the Bay Area over a year ago to focus on advancing the state of the art and the design and assembly of solar cells and modules. We look forward to talking with you about this development on our March ‘14 webcast.

Well here is your spoiler alert:  Hyperion is going to be  a “disruptive technology” and a “game changer” that can and will be applied across all of GTAT’s platforms in the foreseeable future and for the foreseeable future.   During the March 14, 2014 webcast GT management will most certainly focus some of it’s attention on the design and assembly of solar cells and modules.  I’ve done my best to translate the patents so everyone can understand the key takeaway.  I’m sure the sci-fi team at GT Advanced Technologies will give a cleaner explanation but this is my best shot!  Essentially GT has patented a new process that likely creates the lowest cost, thinnest and most efficient solar cell technology on the market   The process to create this amazing innovation begins by leverage GT’s Hyperion technology (which is protected by over 50 patents) to fire hydrogen ions against a solar cell to create super thin solar cells that can be used in PV technology (solar panel).   The super thin solar cells are more efficient due to design (cutting angle) allowing them to improve efficiency.  They are lower cost due to Hyperion exfoliating abilities which allow for one of if not the thinnest solar cell produced in the industry (I hope the analysts ask if TG doesn’t tell us anyways).  Further cost reductions are found because the Hyperion method of exfoliating the solar cells reduces waste that results from through traditional “kerf” methods.

Obscure Analyst’s Spoiler Alert Takeaway: GTAT may have just come up the most efficient solar cells available on the market today due to the degree of the cut plane of the solar cells which allows for more light absorption than traditional methods.  The cost of the solar cells is greatly reduced because Hyperion allows up to a 2 for 1 benefit on thinness (current benefit might be 1.75 to 1) but it was 2:1 when GTAT acquired Twin Creeks in 2012.   Lastly, the method of using Hyperion versus traditional kerf methods of cutting solar cells will greatly reduce the amount waste, which will lead to further cost savings.  If I had to put names on who they are partnering with I would go with Yingli Green Energy or Trina Solar, who finished 2013 as #1 and #2 in PV supply.  Below are two of GTAT’s  key patents related to the growth and bonding of thin lamina.

 
EPITAXIAL GROWTH ON THIN LAMINA 

BACKGROUND OF THE INVENTION

[0001] Sivaram et al., U.S. patent application Ser. No. 12/026,530, “Method to Form a Photovoltaic Cell Comprising a Thin Lamina,” filed Feb. 5, 2008, owned by the assignee of the present invention and hereby incorporated by reference, describes fabrication of a photovoltaic cell comprising a thin semiconductor lamina formed of non-deposited semiconductor material. Using the methods of Sivaram et al., photovoltaic cells, rather than being formed from sliced wafers, are formed of thin semiconductor laminae without wasting silicon through kerf loss or by fabrication of an unnecessarily thick cell, thus reducing cost. The same donor wafer can be reused to form multiple laminae, further reducing cost, and may be resold after exfoliation of multiple laminae for some other use.

[0002] Referring to FIG. 1A, in embodiments of Sivaram et al., a semiconductor donor wafer 20 is implanted through first surface 10 with one or more species of gas ions, for example hydrogen and/or helium ions. The implanted ions define a cleave plane 30 within the semiconductor donor wafer. As shown in FIG. 1B, donor wafer 20 is affixed at a first surface 10 to receiver 60. Cleaving is most easily achieved by heating, for example to temperatures of 500 degrees C. or more. Referring to FIG. 1C, lamina 40 is heated and cleaves, or exfoliates, from donor wafer 20 at cleave plane 30, creating second surface 62. It has been found that the step of implanting to define the cleave plane may cause damage to the crystalline lattice of the monocrystalline donor wafer. This damage, if unrepaired, may impair cell efficiency. A relatively high-temperature anneal, for example at 900 degrees C., 950 degrees C., or more, will repair most implant damage in the body of the lamina.

[0003] In embodiments of Sivaram et al., additional processing before and after the cleaving step forms a photovoltaic cell comprising semiconductor lamina 40, which is between about 0.2 and about 100 microns thick. In other embodiments of Sivaram et al., lamina 40 may be, for example, between about 0.2-50 microns thick, between about 1-20 microns thick, between about 1-10 microns thick, between about 4-20 microns thick, or between about 5-15 microns thick, though any thickness within the named range is possible. FIG. 1D shows the structure inverted, with receiver 60 at the bottom, as during operation in some embodiments of Sivaram. Receiver 60 may be a discrete receiver element having a maximum width no more than 50 percent greater than that of donor wafer 20, and preferably about the same width, as described in Herner, U.S. patent application Ser. No. 12/057,265, “Method to Form a Photovoltaic Cell Comprising a Thin Lamina Bonded to a Discrete Receiver Element,” filed on Mar. 27, 2008, owned by the assignee of the present application and hereby incorporated by reference. Alternatively, a plurality of donor wafers may be affixed to a single, larger receiver, and a lamina cleaved from each donor wafer.

0004] In summary, the primary stages of producing a lamina are ion implantation, exfoliation (cleaving the lamina from the donor wafer), and annealing (to repair defects in the lamina).


BONDING OF THIN LAMINA

BACKGROUND

[0002] Sivaram et al., U.S. patent application Ser. No. 12/026,530, “Method to Form a Photovoltaic Cell Comprising a Thin Lamina,” filed Feb. 5, 2008, and issued as U.S. Pat. No. 8,481,845, owned by the assignee of the present disclosure and hereby incorporated by reference, describes fabrication of a photovoltaic cell comprising a thin semiconductor lamina formed of non-deposited semiconductor material. Using the methods of Sivaram et al., and others, photovoltaic cells and other electronic devices, rather than being formed from sliced wafers, are formed of thin semiconductor laminae without wasting silicon through kerf loss or by fabrication of an unnecessarily thick cell, thus reducing cost. The same donor wafer can be reused to form multiple laminae, further reducing cost, and may be resold after exfoliation of multiple laminae for some other use. Methods are needed for handling thin lamina in order to process them into electronic devices.

SUMMARY

[0003] Methods and apparatus are provided for bonding a thin lamina to a carrier, the methods may comprise providing a thin lamina wherein the lamina has a first side and a second side and wherein the first side of the lamina is separably contacted to a support plate; providing a first carrier having a first side and a second side and wherein the first side comprises a layer of adhesive material; contacting the second side of the thin lamina to the first side of the first carrier; fixing the lamina to the first carrier wherein the fixing comprises applying a first application of heat and a first application of pressure to a portion of the lamina and the first carrier; removing the support plate; applying a second application of heat and a second application of pressure to the lamina and the first carrier wherein the second application of heat and the second application pressure promotes an adhesive bond between the lamina and the first carrier and wherein the second application of pressure comprises moving the lamina, the first carrier and the cover sheet between a pair of rollers.

Two additional relevant patents are below

Photovoltaic Cell Comprising A Thin Lamina Having A Rear Junction And Method Of Making 
ASYMMETRIC SURFACE TEXTURING FOR USE IN A PHOTOVOLTAIC CELL AND METHOD OF MAKING 

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Comments
  1. Matt. Couldn’t sleep last night thinking about the laminate solar cell. The patent that shows thin layers of substrate should be comprised of Silicon and and maybe Sapphire as a insulator with several of these layers forming a solar cell. And a highly efficient one. One so efficient that its going to power a Tesla with a breakthrough battery technology that will allow it to operate forever. Its coming. With Apples money and Dan squiller and Elon Musk’s ideas, and the whole team of officials working for these company’s, its coming.

    Not only that, the very efficient solar panels and batteries will allow residential and commercial installations. Its coming.

    The Saudi contract just may have been held up to let this play out more. Costs will go down and maybe large solar complexes will not be needed.

    This is the disruptive technology that we need to get rid of the combustion engine and the smog producing utility company’s. I know, in the distant future.

    Like

  2. Bill Travers says:

    Matt, just a thank you for all the hard work you do providing excellent data and information on GTAT. I have invested in the company off and on with the last time being in 2012, but closed out all my positions around that time. Getting up there in age (71 now) so have to be more careful.

    When I saw the contract award with Apple, I perked up and started watching for signs/info that might aid me in making a decision to invest in GTAT again. Matt, you and a couple of others on the yahoo message board were most helpful, bought back in January, and have been most pleased with the results.

    Thank you and keep up the good work
    Bill

    Liked by 1 person

  3. Michael Slattery says:

    Matt could you please take a moment and address the likelihood of a buyout in the near future? This entire company now seems like a dream come true for GE. I can’t see them being around as a free standing entity for very long with this much potential to impact much large corporation’s bottom lines.

    I took a position in GTAT thanks to a good friend alerting me to your SA post and I am grateful to both of you,

    Michael

    Like

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