Thin film formation of wet chemically deposited NiOx and parasitic oxides at NiOx/Si interfaces during high-temperature annealing of selective contacts in perovskite/Si tandem solar cells

Lange S, Fett B, Hähnel A, Müller A, Herbig B, Naumann V, Sextl G, Mandel K, Hagendorf C (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Solar Energy Materials and Solar Cells Elsevier

Book Volume: 240

Article Number: 111724

DOI: 10.1016/j.solmat.2022.111724

Abstract

Wet chemically deposited NiOx is a promising hole-transport material in perovskite/Si tandem solar cells due to its high work function, chemical stability, and low cost. However, it requires subsequent annealing that may lead to the formation of SiOz at the Si interface to the bottom cell. These layers of nm thickness exhibit non-stoichiometric chemical composition and are detrimental for charge transport and passivation. In this contribution, we investigate the atomic and electronic structure as well as chemical properties of NiOx layers on Si after wet chemical deposition and annealing in air between 200 °C and 600 °C. For this purpose, photoelectron spectroscopy, X-ray diffraction, differential thermal analysis/thermogravimetric analysis coupled with Fourier transform infrared spectroscopy, time-of-flight secondary ion mass spectrometry, and electron-energy loss spectroscopy in a scanning transmission electron microscope are applied. After deposition and annealing at 200 °C, a mixed bulk phase consisting of NiOxHy is found which transforms to pure NiOx above 300 °C. A parasitic SiOz layer is observed at the NiOx/Si interface after this process, with a thickness of 3–4 nm after annealing at 500 °C. The impact of this interfacial layer for electrical current transport will be discussed concerning optimized performance and integrability in perovskite/silicon tandems.

Authors with CRIS profile

Bastian Fett Professur für Anorganische Chemie Karl Mandel Professur für Anorganische Chemie

Involved external institutions

Fraunhofer-Center für Silizium-Photovoltaik (CSP) DE Germany (DE) Fraunhofer Institut für Silicatforschung (ISC) DE Germany (DE)

How to cite

APA:

Lange, S., Fett, B., Hähnel, A., Müller, A., Herbig, B., Naumann, V.,... Hagendorf, C. (2022). Thin film formation of wet chemically deposited NiOx and parasitic oxides at NiOx/Si interfaces during high-temperature annealing of selective contacts in perovskite/Si tandem solar cells. Solar Energy Materials and Solar Cells, 240. https://doi.org/10.1016/j.solmat.2022.111724

MLA:

Lange, Stefan, et al. "Thin film formation of wet chemically deposited NiOx and parasitic oxides at NiOx/Si interfaces during high-temperature annealing of selective contacts in perovskite/Si tandem solar cells." Solar Energy Materials and Solar Cells 240 (2022).

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