Ex Parte ATWATER et al

Patent Trial and Appeal Board

Dec 11, 2018

12176057 (P.T.A.B. Dec. 11, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
12/176,057 07/18/2008
26138 7590 12/12/2018
Joseph R. Baker, APC
Gavrilovich, Dodd & Lindsey LLP
4370 La Jolla Village Drive, Suite 303
San Diego, CA 92122
FIRST NAMED INVENTOR
Harry A. ATWATER
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
00016-051001/CIT 4946 1783
EXAMINER
KOLLIAS, ALEXANDER C
ART UNIT PAPER NUMBER
1767
MAIL DATE DELIVERY MODE
12/12/2018 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE
THE PATENT TRIAL AND APPEAL BOARD
ExparteHARRY A.ATWATER, 1
Brendan M. Kayes, Nathan S. Lewis, James R. Maiolo III, and
Joshua M. Spurgeon
Appeal2017-002282 2
Application 12/176,057
Technology Center 1700
Before LINDA M. GAUDETTE, MARK NAGUMO, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.
NAGUMO, Administrative Patent Judge.
DECISION ON APPEAL
Harry A. Atwater, Brendan M. Kayes, Nathan S. Lewis,
James R. Maiolo III, and Joshua M. Spurgeon ("Atwater") timely appeal
1 The real party in interest is identified as the California Institute of
Technology. (Appeal Brief, filed 5 August 2016 ("Br."), 2.)
2 A hearing scheduled for 17 January 2019 was waived. (Communication
dated 19 November 2018).
Appeal2017-002282
Application 12/176,057
under 35 U.S.C. § 134(a) from the Final Rejection3 of claims 1-6, 8, 10, 21,
and 23-26. 4 We have jurisdiction. 35 U.S.C. § 6. We affirm-in-part.
OPINION
A. Introduction 5
The subject matter on appeal relates to devices based on arrays of
semiconductor wires that are said to be useful for converting light into
electricity. (Spec. 1 [0004].)
According to the '057 Specification, "[a] key constraint in photon
absorbers for solar energy conversion is that the material must be
sufficiently thick to absorb most of the solar photons with energies above the
material's band gap, yet sufficiently pure to have a high minority carrier
diffusion length for effective collection of the photo generated charge
carriers." (Id. at 2 [0005].) Inexpensive materials are said to tend to have
high levels of impurities or high densities of defects, resulting in low
minority-carrier diffusion lengths. (Id. at [0006].) As a result, such
3 Office Action mailed 06 October 2015 ("Final Rejection"; cited as "FR"),
incorporating by reference rejections set forth in an Office Action
mailed 21 April 2015 ("OA").
4 Remaining copending claims 11, 13, 14, and 16 have been withdrawn
from consideration by the Examiner (FR 1, § 5a), and are not before us.
5 Application 12/176,057, Structures of ordered arrays of semiconductors,
filed 18 July 2008, claiming the benefit of three provisional applications
filed 19 July 2007, a provisional application filed 28 August 2007, and a
provisional application filed 13 May 2008. We refer to the
"'057 Specification," which we cite as "Spec."
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Appeal2017-002282
Application 12/176,057
materials "cannot be readily incorporated into planar solar cell structures
with high energy-conversion efficiency." (Id.)
The inventors seek patent protection for photocells formed with
vertically-aligned semiconductor wires that are long "in the direction of
received light, but with relatively small radii to facilitate efficient collection
of [photo-generated charge] carriers." (Id. at 3 [0008].) An embodiment of
such a cell is illustrated schematically in Figure IA, below.
Light
\.1 l \
\ \ \ \
il{l
\\'))
++-tt
130
,-vv...,....,.......... '\ ....
\__/
I .
) )
'-----~ ..................... ,, ................ (
\
\110
{Figure 1 A shows a photoelectrochemical cell}
Vertically aligned semiconductor wires 1406 make electrical contact at one
end with conductive base 110, and at the other end with liquid electrolyte (or
conductive polymer) 130. (Id. at 7 [0034].) In the words of the
Specification, "[ o Jptimal efficiencies are expected when each wire has a
radius comparable to the minority carrier diffusion length. Smaller radii
produce increased surface area and thus increase surface and junction
6 Throughout this Opinion, for clarity, labels to elements are presented in
bold font, regardless of their presentation in the original document.
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Appeal2017-002282
Application 12/176,057
recombination with little concomitant improvements in carrier collection."
(Id. at 11 [0044].)
Claim 1 is representative and reads:
A device comprising:
a base conducting layer [110];
an ordered array of elongated semiconductor rod
structures [140]
having lengths of 20-30 µm
with micron sized diameters and wherein the diameters
are at least 1.5 microns and less than the length,
wherein the elongated semiconductor rod structures
have length dimensions defined by
adjacent ends in electrical contact with at least portions
of the base conducting layer and
distal ends not in contact with the base conducting
layer; and
a charge conducting layer [130] selected from the group
consisting of a liquid electrolyte and a conducting polymer,
wherein
at least some portions of the charge conducting layer
are in electrical contact with
one or more elongated semiconductor rod structures of the
plurality of the elongated semiconductor rod structures
along at least portions of the length dimensions of the
one or more elongated semiconductor rod structures,
wherein the elongated semiconductor rod structures
absorb received light, and
wherein the elongated semiconductor rod structures are
comprised of doped or undoped material selected from
the group consisting of crystalline silicon, amorphous
silicon, micromorphous silicon, protocrystalline
silicon, nanocrystalline silicon, copper-indium
selenide, copper indium gallium selenide, gallium
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Appeal2017-002282
Application 12/176,057
arsenide, gallium arsenide phosphide, indium
phosphide, a-Si:H alloy, and combinations thereof.
(Claims App., Br. 12; some formatting, emphasis, and bracketed labels to
elements illustrated in Figure IA added.)
The Examiner maintains the following grounds of rejection 7, 8 :
A. Claims 1, 4---6, 8, 10, 21, and 23-26 stand rejected under 35
U.S.C. § I03(a) in view of the combined teachings ofYang9
and Tsakalakos. 10
Al. Claims 2 and 3 stand rejected under 35 U.S.C. § I03(a) in view
of the combined teachings of Yang, Tsakalakos, and Alexiev. 11
B. Claim 26 stands rejected under 35 U.S.C. § 112(1) for lack of
adequate written description.
Atwater elects to partially withdraw the appeal as to: claims 4---6, 8,
10, 21, and 23-26; and claims 2 and 3, rejected as obvious in view of cited
prior art; and as to claim 26, rejected under 35 U.S.C. § 112(1), for lack of
written description. (Br. 10-11, citing Manual of Patent Examination
7 Examiner's Answer dated 5 October 2016 ("Ans.").
8 Because this application was filed before the 16 March 2013, effective
date of the America Invents Act, we refer to the pre-AIA version of the
statute.
9 Peidong Yang et al., Nanowire array and nanowire solar cells and
methods for forming the same, U.S. Patent Application Publication
2005/0009224 Al (2005).
10 Loucas Tsakalakos et al., High efficiency inorganic nanorod-enhanced
photovoltaic devices, U.S. Patent Application Publication 2006/0207647 Al
(2006).
11 D. Alexiev et al., Minority carrier diffusion lengths for high purity liquid
phase epitaxial GaAs, (2004), obtained from the Archiv database:
http://arxiv.org/ftp/cond-mat/papers/0409/0409176.pdf
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Appeal2017-002282
Application 12/176,057
Procedure§ 1215.03 (Partial Withdrawal [of Appeal]).) Atwater states
further that an amendment canceling these claims will be filed should the
appeal proceed to the Board. (Id.)
B. Discussion
The Board's findings of fact throughout this Opinion are supported by
a preponderance of the evidence of record.
Although no amendment canceling rejected but non-appealed
claims 2-6, 8, 10, 21, and 23-26 appears to be of record, notwithstanding
Atwater' s representation that such an amendment would be filed (Br. 10-
11 ), that incident is unimportant, as we summarily affirm the rejections of
those claims. 37 C.F.R. § 4I.37(c)(l)(iv) (2016).
Atwater urges, inter alia, that the Examiner erred harmfully in finding
(OA 5, 11. 1--4) that Yang's disclosure ofnanowires having an "aspect ratio
greater than about 20 or even 120, and a length greater than about 15
or 20 microns" (Yang 1 [0011]) would have disclosed or suggested
semiconductor wires having a diameter of 1.5 microns and a length of 20-
30 microns, as required by claim 1. Most compellingly, Atwater cites the
testimony12 of co-inventor Nathan S. Lewis, Professor of Chemistry at the
California Institute of Technology, who has extensive experience in areas
relevant to the present invention. Professor Lewis testifies that, under the
conditions used by Yang to grow nano wires, "only submicron diameter sized
wires can result from the methods and teachings of Yang." (Lewis
12 Declaration of Nathan S. Lewis, signed and filed 29 September 2014
("Lewis Deel.").
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Appeal2017-002282
Application 12/176,057
Deel. ,r 7.) In further support of his statement, Professor Lewis points out
that the publication Greene, 13 which is co-authored by the three inventors
listed on the Yang patent application publication, states that when using the
disclosed methodology (the same methodology used by Yang), "[g]rowth
from a substrate coated in a thin layer of ZnO nanoparticles decreases the
diameter [of the wires and rods] to below 200 nm." (Greene 7537, col. 1,
11. 4--5 (emphasis added).) Professor Lewis testifies further that the
"Tsakalakos et al. methods have been optimized to produce wires having
submicron sized diameters." (Lewis Deel. ,r 8; see also
Tsakalakos 4 [0066]: ("Typically, the I-dimensional nanostructures used in
the above-described photovoltaic devices have a diameter between
about 1 nm and about 300 nm. They also typically have a height between
about 50 nm and about 50 µm. In some embodiments, the I-dimensional
nanostructures vary in height and diameter within the array.").) 14
The Examiner does not dispute the accuracy of Professor Lewis's
testimony. The Examiner's reliance on the open-ended statements of Yang
to support the conclusion that "the reference discloses a length range which
overlaps that presently claimed" (FR 6, ,r 17), and that such an overlap
renders the range recited in the claim prima facie obvious (id. (citing, e.g., In
13 Lori E. Greene et al., Solution-grown zinc oxide nanowires, 45 Inorg.
Chem. 7535--43 (2006).
14 It has not escaped our attention that Tsakalakos includes the following
definition: "A 'I -dimensional nanostructure,' as defined herein, refers to
nanotubes, nanorods, nanocylinders, and nano wires of inorganic
composition, generally having submicron diameters and typically having
diameters below 300 nm, and wherein their I-dimensionality originates from
their large aspect ratios." (Tsakalakos 3 [0045].)
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Application 12/176,057
re Harris, 409 F.3d 1339 (Fed. Cir. 2005))), overlooks the underlying
presumption in those cases that the compositions at issue were enabled, i.e.,
obtainable without undue experimentation. The preponderance of the
evidence of record indicates that the methods described by Yang and by
Tsakalakos result in smaller diameter wires than required by claim 1.
Moreover, the Examiner does not direct our attention to any credible
evidence of record that other techniques were known to persons having
ordinary skill in the art, at the time of the invention (i.e., the filing date,
18 July 2008), to make ordered arrays of semiconductor wires having
diameters greater than 1.5 microns, and lengths of 20-30 microns, as
required by claim 1. Thus, the Examiner has not shown that it would have
been known how to make such structured arrays without undue
experimentation. That which was not enabled cannot have been obvious,
because without enablement, there cannot have been a reasonable
expectation of success.
We therefore reverse the rejection of claim 1 as obvious in view of the
combined teachings of Yang and Tsakalakos.
C. Order
It is ORDERED that the rejection of claim 1 is reversed.
It is FURTHER ORDERED that the rejections of claims 2---6, 8, 10,
21, and 23-26 are affirmed summarily.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED-IN-PART
8