Impact of a Thin Sacrificial Mo Layer on the Formation of the Wide Band Gap ACIGSe Absorber/ITO Thin-Film Solar Cell Interface

Demling A, Gutzler R, Almeida Alves CF, Wilks RG, Félix R, Hariskos D, Paetel S, Cerqueira R, Sadewasser S, Witte W, Bär M (2025)

Publication Type: Journal article

Publication year: 2025

Journal

ACS Applied Materials and Interfaces American Chemical Society

DOI: 10.1021/acsami.5c02315

Abstract

The effect of a thin sacrificial Mo interlayer on the device performance of a thin-film solar cell based on a wide band gap (1.46 eV) (Ag, Cu)(In, Ga)Se2 (ACIGSe)/indium tin oxide (ITO) layer stack and its influence on the chemical composition at the absorber/transparent back contact (TBC) interface are investigated. The solar cell without a Mo interlayer exhibits an efficiency of less than 1%, whereas the inclusion of an approximately 10 nm thick Mo interlayer produces a cell with an efficiency of 10.1%, with the fill factor being more than tripled. Scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy line scans show strong GaOx formation at the absorber/transparent conductive oxide (TCO) interface in a Mo-free sample and a significant decrease in the amount of GaOx in a sample with the Mo interlayer included. Cleaving the absorber/TBC interface allowed us to study the absorber back side and the exposed ITO TCO using hard X-ray photoelectron spectroscopy. The nearly complete conversion of the metallic Mo interlayer into MoSe2 and MoOx is revealed. It is suggested that the formation of MoOx, which may act as a hole-selective contact, together with inhibited GaOx formation might be responsible for the pronounced performance enhancement for the cell with the thin Mo interlayer.

Authors with CRIS profile

Marcus Bär

Involved external institutions

Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) DE Germany (DE) Zentrum für Sonnenenergie- und Wasserstoff-Forschung (ZSW) DE Germany (DE) INL - International Iberian Nanotechnology Laboratory PT Portugal (PT)

How to cite

APA:

Demling, A., Gutzler, R., Almeida Alves, C.F., Wilks, R.G., Félix, R., Hariskos, D.,... Bär, M. (2025). Impact of a Thin Sacrificial Mo Layer on the Formation of the Wide Band Gap ACIGSe Absorber/ITO Thin-Film Solar Cell Interface. ACS Applied Materials and Interfaces. https://doi.org/10.1021/acsami.5c02315

MLA:

Demling, Angelika, et al. "Impact of a Thin Sacrificial Mo Layer on the Formation of the Wide Band Gap ACIGSe Absorber/ITO Thin-Film Solar Cell Interface." ACS Applied Materials and Interfaces (2025).

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