Cells and modules with passivating contacts - …...2019/05/09 · Cells and modules with passivating contacts - POLO technology F. Haase, R. Peibst Institute for Solar Energy Research

PERC and beyond – next generation modules, what can we expect?

Webinar: 09.05.2019

Cells and modules with

passivating contacts -

POLO technology

F. Haase, R. Peibst

Institute for Solar Energy Research Hamelin (ISFH)

Am Ohrberg 1, 31860 Emmerthal, Germany

[email protected]

www.isfh.de

mailto:[email protected]

http://www.isfh.de/

ISFH

• Founded in 1987

• 10.2 Mio € turn over (2017)

• 145 employees

• R&D in photovoltaics and solar systems

• R&D in cooperation with industrial

partners

• Focus on applied research in c-Si PV

09.05.2019Webinar: PERC and beyond

F. Haase2

PERC+ solar cell

• PERC cell with local contacts at

the rear but full area aluminum

• PERC+ cell with Al fingers for

bifaciality and less aluminum

consumption and bow [1]

[1] T. Dullweber et al., Proc. of the 31st EUPVSEC, p.341 (2015).


F. Haase3

PERC+ solar cell - limitations

• Current industrial PERC+ cells are

limited by emitter and contact

recombination[1]

• Are there less limiting contacts?

[1] C. Kruse et al., IEEE Journal of Photovoltaics 8 (3), 683-688, (2018).

e-selective contact

h-selective contact (Al-BSF)


F. Haase4

Poly-Si on oxide (POLO) is a nano-PERC

• Efficiency limitation by contacts:

25 %[1,2]

PERC POLO

P-doping 1020 cm-3

1 µm

5 nm2 nm

Al-doping 5x1018 cm-3

1 mm

100 nm

50 µm


F. Haase5

• Efficiency limitation by contacts:

29 %[1]

• Less contact fraction but still less

contact resistance

[1] R. Brendel et al., Proc. of the 35th EUPVSEC, p. 39 (2018)

[2] J. Zhao et al., Appl. Phys. Lett. 73 (14), p. 1991-1993 (1998)

POLO – double side contacted industrial

solar cell concepts

• Various cell concepts / process sequences / poly-Si depositions under

investigation[1]

• Benefit of POLO: high-temperature stable, compatible with high-T. screen-print

→ Possible “add-on” for PERC mainstream

• Using mostly same process equipment could be interesting for upgrading

existing PERC lines

• Metal layout same as for PERC → Module integration similar as for PERC


F. Haase

[1] R. Peibst et al., accepted as presentation at 36th EUPVSEC (2019)

POLO – double side contacted industrial

solar cells

• Efficiency gain over PERC (simulated with measured input parameter):

+0.2-0.4 % +0.2-0.4 % +0.8-1.2 % +1.4-1.8 % +0.6-0.9 %

• Costs depend on number of process steps (can be more or less than PERC)


F. Haase

PERC+ POLO-RS PERC+POLO POLO2-FJ POLO2-BJ TOPCon

p+ and n+ POLO junctions: POLO-IBC cell

• POLO-IBC solar cell

• P-type Si world record

• h = 26.1 %[1] independently confirmed

at ISO17025-accredited Calibration

and Test Center, ISFH-CalTeC

[1] F. Haase et al., Solar Energy Materials and Solar Cells 186,184 (2018)


F. Haase8

Industrial POLO-IBC cell[1]

• Same process equipment as PERC+

except poly-Si deposition tool

• 25 % efficiency potential simulated

[1] F. Haase et al., accepted as presentation at 46th IEEE PVSC 2019


F. Haase9

POLO-IBC module

• Ribbon or Multiwire cell

interconnection possible

• Same process equipment for

module manufacturing as PERC+

Multiwire

• High robustness against efficiency

losses by cell cracks

• High efficiency modules for vehicle

integrated PV

[1] M. Hendrichs et al., Proc. of the 42nd IEEE PVSC (2015), DOI: 10.1109/PVSC.2015.7355645


F. Haase10

Wire cell interconnection without busbars[1]

POLO cells – degradation mechanisms

Known from PERC and also relevant for

POLO

• Light Induced Degradation (LID)

• Light and elevated Temperature

Induced Degradation (LeTID)

• Potential Induced Degradation (PID)

of bifacial cells

Degradation of POLO contacts

under investigation


F. Haase11

LeTID on multicrystalline PERC cells [1]

[1] K. Ramspeck et al., Proc. of the 27th EUPVSC, 861 (2012)

Conclusion and Outlook

• PERC will stay mainstream and keep on improving

• Pioneer work of ISFH to working principle and potential of POLO contacts

• POLO contacts do not limit the cell anymore

• 26.1 % record efficiency with POLO-IBC

• Various cell concepts / process sequences / poly-Si depositions under

investigation

• First production lines built for passivating contacts

Webinar: PERC and beyond

F. Haase09.05.2019 12

Acknowledgments

13

Many thanks to

• … director Prof. R. Brendel and the whole team @ ISFH and MBE

• … industrial partners

• … the federal state of Lower Saxony, the German Ministry for Economic Affairs and Energy,

and the European Commission for funding

• … you for your kind attention!

For further questions please contact:

Dr. Felix Haase

[email protected]

www.isfh.de


F. Haase

mailto:[email protected]

http://www.isfh.de/

Cells and modules with passivating contacts - …...2019/05/09 · Cells and modules with passivating contacts - POLO technology F. Haase, R. Peibst Institute for Solar Energy Research

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