Bay  Area  Photovoltaic  Consortium  

Bay  Area  Photovoltaic  Consor3um  (BAPVC)  and  Solar  Cell  Research  at  

Stanford  University      

Yi  Cui,  Co-­‐Director  of  BAPVC  Department  of  Materials  Science  and  Engineering    

 Stanford  University  Stanford  Ins3tute  for  Materials  and  Energy  Sciences  

SLAC  Na3onal  Accelerator  Laboratory                .  

     This  material  is  based  upon  work  supported  by  the  Department  of  Energy  through  the  Bay  Area  Photovoltaic  Consor@um  under  Award  Number  DE-­‐EE0004946.  

   

BAPVC Objec@ve:  Dollar-­‐per-­‐WaK  

To  achieve  $1/W  installed  system,  it  is  cri@cal  to  get  the  module  cost  below  $0.50/W.  

Bay  Area  Photovoltaic  Consortium        2  

DOE Sunshot Initiative

BAPVC DOE  Photovoltaic  Manufacturing  Ini@a@ve  

-­‐   Perform  industry-­‐relevant  R&D  at  University/Na@onal  Labs  to  facilitate  high-­‐volume  PV  manufacturing  -­‐   Establish  scope  of  research  with  explicit  industry  support  -­‐   Develop  highly  trained  workforce  -­‐   Speed  up  commercializa@on  of  cu[ng-­‐edge  PV  technologies  

 

BAPVC  plans  to  achieve  all  these  objectives  

Bay  Area  Photovoltaic  Consortium        3  

BAPVC BAPVC  Objec@ve  

-  Conduct industry-relevant research: $25M from DOE + industrial support -  High efficiencies with low production cost -  The whole photovoltaic module approach towards < $0.50 per watt

Bay  Area  Photovoltaic  Consortium      4  

BAPVC

Bay  Area  Photovoltaic  Consortium      5  

Lead Institutions Partner Institutions

BAPVC  

- Co-Director: Yi Cui (SU), Ali Javey (UCB) - Executive Director: John Benner - Industrial Liaison: Steve Eglash - Chairman of Industrial Board: Richard Swanson

BAPVC Industrial  Members  

Bay  Area  Photovoltaic  Consortium        6  

17 Companies

GE DuPont Exxon-Mobil Schlumberger 3SUN Asahi Glass Company Robert Bosch LLC BASF Corning

Heliovolt Konica Minolta Stion Total American Services/SunPower Alta Devices Bandgap Engineering EpiSolar Rose Street Labs

BAPVC Our  Whole  Module  Approach  to  

Reach  $0.50/W  Modules  

Bay  Area  Photovoltaic  Consortium        7  

    An@reflec@on      

Absorber  and  junc@on  

Substrate  

Transparent  electrode  

Encapsula@on  

BoKom  contact  

Encapsulation

50  µm  

Metal  nanowire    transparent  electrode  

Novel electrodes

Nanocone  substrate  

500nm  

Substrates

Advanced materials characterization

Absorber  and  junc3on  

Thin film absorber

Nanoscale photon management

Substrate

H2O, O2, H2other active chemical

species

photochemical reactions

cracking and debonding

UV Exposure

defect evolution in nanomaterial

layers

surface weathering

Substrate

H2O, O2, H2other active chemical

species

photochemical reactions

cracking and debonding

UV Exposure

defect evolution in nanomaterial

layers

surface weathering

Reliability

BAPVC

Bay  Area  Photovoltaic  Consortium      8  

Thrust  Area  Silicon  Absorbers  and  Cells    

 Leader        Sanjay  Banerjee    Liaison    Marc  Vermeersch

Cui   Stanford   High  Efficiency  Ultrathin  Sericon  Solar  Cells  

S.  Banerjee   Texas   Thin  Crystalline  RPCVD  Back  Contact  Cells  

Stuart  Bowden   ASU   Laser  Wafering  

van  Hest   NREL  Module  Interconnects  and  Crystalline  Film  Silicon  by  Atmospheric  Pressure  Processing  

Subramanian   Berkeley   High�-­‐resolu@on,  high�-­‐speed  prin@ng  of  PV  contacts    

BAPVC Advanced  Contacts  via  Gravure  prin@ng  15

00 µ

m

12.55 µm

Gravure printing: Line width < 10 µm Line-edge roughness < 1 µm . Print speed 10x faster than current PV screen printers Reduced shadowing loss 80% reduction in Ag consumption Research in for Cu substitution

High-resolution, high-speed printing of PV contacts, V. Subramanian, Berkeley

BAPVC Ultra  Thin  Silicon  for  Solar  Cells  

Y. Cui, S. Fan

Silicon  Absorber  and  Cells

BAPVC

Bay  Area  Photovoltaic  Consortium      11  

Thrust  Area  Photon  Management  and  Transparent  Conductors    

 Leaders        Shanhui  Fan  and  Joel  Ager    Liaison    TBD  

Brongersma   Stanford   Percola@ng  Transparent  Metallic  Electrodes  for  Solar  Cells  

Fan   Stanford   Theory  and  simula@on  of  photon  management  in  nanostructured  solar  cells  

Wladek/Ager   LBNL   New  Transparent  Conduc@ng  Oxides  

Harry  Atwater   Cal  Tech  Solar  Cell  Efficiency  Enhancement  via  Light  Trapping  in  Resonant  Dielectric  Sphere  Arrays  

Kaustav  Banerjee  

U.C.  Santa  Barbara  

Graphene  Electrode  Eng.  for  Photovoltaic  Applica@on  

Ning  Wu  Colorado    Mines  

Large-­‐Area,  Fast,  and  Electric-­‐Field  Assisted  Con@nuous  Coa@ng  for  Nanostructured  Photon  Management  

Nanostructured Metals and Semiconductors for Enhanced Solar Energy Harvesting

� Metal nanostructures exhibit a strong, resonant light-matter interaction

� This interaction is tunable by changing the structure shape, size, environment,..

Metal nanostructures offer intriguing opportunities for enhancing solar cells

� Metal nanostructures deposition is scalable and low cost

Ultimate, best design of nanostructure patterns requires intuition and simulations

Metal stripes enhance light absorption •  Exploiting plasmon resonances of

metal stripes •  Coupling to Si waveguide modes

BAPVC

Bay  Area  Photovoltaic  Consortium      13  

Thrust  Area  This Film Absorbers and Cells

 Leader        Hugh  Hillhouse    Liaison    BJ  Stanbery

Clemens/Bent  Stanford   Bandgap  Grading  in  Cu2ZnSn(S,Se)4  Solar  Cells  +  SnS  based  PVs  Toney   SLAC   Advanced  Materials  Characteriza@on  Hanket   Delaware   Advanced  Evapora@on  Source  Design  H  Hillhouse   Washington  Development  of  Mul@color  Lock-­‐in  PL  Method  ScoK  Dunham  Washington   Fundamental  Modeling  of  Chalcopyrite  Solar  Cells  M  Lonergan   Oregon   Iden@fying  Problem  Areas  in  CIGS  and  CdTe  Based  Photovoltaic  Devices  

Colin  Wolden  Colorado    Mines  

Non-­‐Equilibrium  Processing  of  CdTe  Absorbers  

Mike  Scarpulla  

Utah   Laser  Processing  CdTe:  Efficiency  &  Manufacturing  

Ferekides   USF   CdTe  Absorbers  Milliron   LBNL   In  situ  characteriza@on  of  grain  growth  in  thin  film  semiconductors  

Yang   Berkeley  Applying  Ca@on-­‐Exchange  Chemistry  to  Nanowire  Arrays  for  Efficient  Solu@on-­‐Processed  Solar  Cells  

SnS  Vapor  Transport  Deposi@on  

2.5  to  5  m/min  First  Solar  ,  LLC  NREL  subcontract  report  NREL/SR-­‐520-­‐39669,  2006  

Art  Wangperawong,  Steve  M.  Herron,  Rory  Runser,  Han-­‐Bo-­‐Ram  Lee,  Stacey  F.  Bent  

14  

BAPVC

Bay  Area  Photovoltaic  Consortium      15  

Thrust  Area  High Performance and Multijunction Cells

 Leader        Tonio  Buonassisi    Liaison    Ben  Lenail

Javey   Berkeley   High  Performance,  Low  Cost,  III-­‐V  Photovoltaics  on  Metal  Foils  

Harris   Stanford   Ultra  high  efficiency  thin  film  mul@-­‐junc@on  solar  cell  

McIntyre   Stanford   Thin  Film  Compound  Semiconductor  Solar  Cells  via  Templated  Growth  

McGehee   Stanford  Low-­‐Cost  Tandem  Solar  Cells  With  Greater  than  20%  Power  Conversion  Efficiency  

Yablonovitch   Berkeley   High  Voc  Solar  Absorbers  for  High-­‐Efficiency,  Spectral-­‐Spli[ng,  Solar  Cells  

Y-­‐H  Zhang   ASU   Si/II-­‐VI  double-­‐heterostructure  solar  cells  

Buonassisi   MIT  Design  principles  and  defect  tolerances  of  silicon  /  III-­‐V  mul@junc@on  interfaces  

P  Bermel   Purdue   Exploratory  Photovoltaic  Modeling  and  Simula@on  

BAPVC

Bay  Area  Photovoltaic  Consortium      16  

Thrust  Area  

Dauskardt   Stanford   Reliability  and  Opera@onal  Life@mes  for  BAPVC  Technologies  

Roger  French  Case  Western  

PV  Module  Performance  &  Life@me  Predic@on:Inser@ng  New  Technologies  Without  Life@me  Penalty  

Segalman/Urban   Berkeley   Novel  polymer-­‐nanocrystal  composite  barrier  layers    

Bernard  Kippelen   GIT  Tailoring  Electrosta@c  Interac@ons  to  Produce  Hybrid  Barrier  Films  for  Photovoltaics  

Encapsulation and Reliability  Leader        Reinhold  Dauskardt    Liaison    Jeffrey  Sternberg  

In-situ UV Effects on Barrier Debonding

0 1 2 3 4 5 6 7 10-11

10-10

10-9

10-8

10-7

10-6

10-5

10-4

Cra

ck G

row

th R

ate,

da/

dt (m

/s)

Strain Energy Release Rate, G (J/m2)

No UV

UV intensity 1.2 mW/cm2

UV intensity 0.6 mW/cm2

Glass Substrate

ITO

ITO

Glass Substrate

Simulated UV Exposure

polysiloxane barrier

•  UV activates new kinetic pathways for debonding •  threshold load for crack growth dramatically reduced •  crack growth rate increases with increase in UV intensity

⎟⎟⎠

⎞⎜⎜⎝

⎛ −+=

η

γν 2sinh htip

o

GGv

dtda

kinetic model

Center  for  Advanced  Molecular  Photovoltaics  (CAMP)  

Stanford •  Michael McGehee (MSE) •  Reiner Dauskardt (MSE) •  Zhenan Bao (Chemical Engineering) •  Stacey Bent (Chemical Engineering) •  Mark Brongersma (MSE) •  Shanhui Fan (EE) •  Alberto Salleo (MSE) •  Michael Toney (SSRL)

 Outside  Stanford  •   Jean-­‐Luc  Brédas  (Georgia  Tech)    •   Brad  Chmelka  (UCSB)  •   Michael  Grätzel  (EPFL  Switzerland)    •   Mark  Thompson  (USC)    •   Jean  Fréchet  (UC  Berkeley  and  KAUST)          KAUST  Collaborators  •  Aram  Amassian  •  Pierre  Beaujuge  

Funding  from  the  King  Abdullah  University  of  Science  and  Technology,  the  Bay  Area  Photovoltaic  Consor@um  and  GCEP  

Hybrid Tandem Photovoltaics

•  Eg ≈ 1.7-2.0 eV •  Voc > 1 V •  < $10/m2

•  Printable •  Low T processing

19

Organic Top Cell

•  Si or CIGS •  Established

technology •  Eg ≈ 1.1 eV, VOC <

0.7 V •  Inefficient in the blue

Inorganic Bottom Cell

1.2 V

0.6 V CIGS%

Mo%

Organic%Absorber%Transparent%Electrode%

Planariza;on%

CdS%

Transparent%Electrode%

Transparent%Electrode%

Beiley and McGehee, Energy and Env Science, 10.1039/c2ee23073a

Hybrid Perovskites

Graetzel et al., Nature 499 (2013) p. 316.

BAPVC

Stanford/SLAC - Precourt Institute for Energy

- Global Climate & Energy Projects - Stanford Institute for Materials & Energy Sciences

- Center for Advanced Molecular Photovoltaics

Outside - UC Berkeley

- Lawrence Berkeley National Lab - PV Industry

-  National-wide institutions -  US Department of Energy