PostDoc(s); ALD nanolayers for advanced silicon and perovskite photovoltaics (V34.3655)

PostDoc(s); ALD nanolayers for advanced silicon and perovskite photovoltaics

Aanstellingsfunctie(s)
(Postdoctoraal) onderzoeker
Faculteit(en)
Faculteit Technische Natuurkunde
FTE
1,0
Sluitdatum
07/02/2019
Referentie
V34.3655

Functieomschrijving

Research
Atomic layer deposition (ALD) is a deposition technique of ultrathin films that is quickly gaining momentum in solar cell research and manufacturing. The Plasma & Materials Processing (PMP) group at the Department of Applied Physics at the TU/e has been one of the main drivers behind the application of ALD in the preparation of solar cells. The PMP group pioneered the passivation of silicon surfaces by ALD Al2O3 films more than a decade ago and had a major contribution to the understanding of the underlying physics as well as to the industrial upscaling of Al2O3 surface passivation in e.g. PERC cells. Currently over 40% of all cells produced are PERC cells and they all contain Al2O3-based backside passivation with a steadily growing market share for ALD. Subsequent research in the PMP group focused on the preparation of silicon heterojunction solar cells, either based on heterojunctions with doped silicon layers in which ALD can be used to prepare transparent conductive contacts (TCO) or based on heterojunctions with metal oxide films in which the metal oxide films are used for surface passivation and selective carrier extraction. This “passivating contacts” research has recently been extended to solar cells based on the combination of polysilicon and tunnel oxide. In these solar cells ALD films can find applications in terms of (sacrificial) hydrogenation layers and TCOs. Beside the research in field of silicon solar cells, the PMP group has also played a leadership role in the introduction of ALD into the preparation of perovskite cells. ALD Al2O3 nanolayers found applications in the improvement of the environmental stability of the solar cells whereas ALD-prepared metal oxides were developed for the application of hole and electron transport layers. This ongoing work focuses both on high-efficiency silicon-perovskite tandem cells as well as on roll-to-roll-produced flexible single-junction perovskite cells.  

Project & Job description
We seek one or two postdocs (1-3 years each) who are interested in working on one or both of the following topics:

1.  ALD for poly-silicon passivating contact solar cells
Since the “rediscovery” of polysilicon (poly-Si) by the silicon research community about 5 years ago, this contact material has been very successfully used in a stack with an ultrathin SiOx layer. Currently, solar cell efficiencies exceeding 25% have been demonstrated by several groups, underlining the promise of poly-Si contacts. Nevertheless, the industrialization of this type of contact is still a challenge, for instance due to upscaling issues, large area uniformity, and metallization that should not degrade the contact performance. Therefore, a consortium of Dutch academic research partners and companies has joined forces to aid this lab-to-fab transition of poly-Si contacts, in particular for p-type poly-Si, which can be effectively used as an incremental upgrade to existing PERC production lines. A crucial part and open fundamental challenge in the current project involves the use of ALD metal oxides to form the ideal poly-Si contact. The project focuses on (i) the exploration of ALD oxides as hydrogenating capping layer for poly-Si layers and (ii) deepening the understanding of the ideal ultrathin oxide interlayer, which is commonly SiOx while other oxides might prove to be valuable too for this application.

2.  ALD for flexible perovskite solar cells
A decade ago “perovskite” solar cells did not even exist, but now they have power conversion efficiencies (PCEs) up to 23%, which is close to record PCEs for commercial PV technologies. The motivation to develop perovskite solar cells is based on the opportunity to turn abundant and inexpensive materials, processed at low temperature and in high volumes at low cost, into high quality semiconductor films, suitable for solar modules. However, several challenges need to be addressed, including environmental profile, long term outdoor performance, up-scaling, perovskite solar cell versatility and its integration and validation of new products. This project, which connects TU/e with research institutes (within the Solliance initiative) and industry, focuses on the development of a perovskite stack with good efficiency, stability and low material cost on polymer substrates. The complete process flow will be carried out on existing equipment and on a roll-to-roll ALD tool at atmospheric pressure, to synthesize electron and hole transport layers. The postdoc researcher at TU/e will support the design and synthesis of these contact layers at Solliance and investigate the perovskite/transport layer interface in terms of chemical composition and opto-electrical properties; energy band diagram of the interface; the complex nature of charge carrier processes (separation, trapping, surface and bulk recombination); etc.  

Location
The work will be performed in the group Plasma & Materials Processing at the Department of Applied Physics at the TU/e. The PMP group focuses on the advancement of the science and technology of plasma and materials processing, a research area which is in essence multidisciplinary and encompasses the research fields of plasma physics, surface science, and materials science. The scientific objective of the group is to obtain “atomic” level understanding of the interaction of plasmas and gases with materials.

Functie-eisen

Qualifications
For the postdoc position, we seek a highly talented, enthusiastic, and exceptionally motivated candidate with doctoral degree in (Applied) Physics, Chemistry, Chemical Engineering, Electrical Engineering or similar. He/she must have experience with solar cell research, have a good understanding of the underlying solar cell physics and have affinity with the synthesis of thin films and materials analysis. Good communication skills in English (both written and spoken) are required.

Responsibilities and tasks
• Develop and optimize ALD processes, analyse material properties and gain understanding of the relation between process and growth properties and the resulting material properties
• Study the thin film materials with respect to their application in solar cells; set up and coordinate experiments with project partners to test the materials in actual solar cells
• Prepare project progress reports, scientific papers and conference communications.
• Daily supervision of BSc and MSc students

Arbeidsvoorwaarden

We offer:
a challenging job in a stimulating internationally renowned research group;
a full-time temporary appointment for initially 1 year, with outlook on appointment for 3 years;
a gross salary of between € 3045,-  and € 4166,- gross per month, depending on knowledge and experience (based on salary scale 10 of CAO Dutch Universities);
• an extensive package of fringe benefits (e.g. excellent technical infrastructure, the possibility of child care and excellent sports facilities).

Informatie en sollicitatie

Information
Information on employment conditions can be found at http://www.tue.nl/en/university/working-at-tue/working-conditions/

For more information about the project, please contact dr. M. Creatore (m.creatore@tue.nl) or prof. W.M. M. Kessels (w.m.m.kessels@tue.nl).

Application
If you are interested in this position, please send in your application by using the 'Apply now'-button on this page.
Applications should include:

  • A cover letter explaining your motivation and qualifications for the position. Please indicate specifically your experience in the areas of silicon and/or perovskite photovoltaics and describe in a separate paragraph why you would be qualified for the position(s).
  • A detailed CV
  • A list of publications and conference contributions
  • Names and contact information of two or more references

Screening of applications will start as soon as applications are received and will continue until the position has been filled.

Please keep in mind; you can upload only 5 documents up to 2 MB each.