Alkali Postdeposition Treatment-Induced Changes of the Chemical and Electronic Structure of Cu(In,Ga)Se2Thin-Film Solar Cell Absorbers: A First-Principle Perspective

Malitckaya M, Kunze T, Komsa HP, Havu V, Handick E, Wilks RG, Bär M, Puska MJ (2019)


Publication Type: Journal article

Publication year: 2019

Journal

Book Volume: 11

Pages Range: 3024-3033

Journal Issue: 3

DOI: 10.1021/acsami.8b18216

Abstract

The effects of alkali postdeposition treatment (PDT) on the valence band structure of Cu(In,Ga)Se 2 (CIGSe) thin-film solar cell absorbers are addressed from a first-principles perspective. In detail, experimentally derived hard X-ray photoelectron spectroscopy (HAXPES) data [ Handick, E.; et al. ACS Appl. Mater. Interfaces 2015, 7, 27414-27420 ] of the valence band structure of alkali-free and NaF/KF-PDT CIGSe are directly compared and fit by calculated density of states (DOS) of CuInSe 2 , its Cu-deficient counterpart CuIn 5 Se 8 , and different potentially formed secondary phases, such as KInSe 2 , InSe, and In 2 Se 3 . The DOSs are based on first-principles electronic structure calculations and weighted according to element-, symmetry-, and energy-dependent photoionization cross sections for the comparison to experimental data. The HAXPES spectra were recorded using photon energies ranging from 2 to 8 keV, allowing extraction of information from different sample depths. The analysis of the alkali-free CIGSe valence band structure reveals that it can best be described by a mixture of the DOS of CuInSe 2 and CuIn 5 Se 8 , resulting in a stoichiometry slightly more Cu-rich than that of CuIn 3 Se 5 . The NaF/KF-PDT-induced changes in the HAXPES spectra for different alkali exposures are best reproduced by additional contributions from KInSe 2 , with some indications that the formation of a pronounced K-In-Se-type surface species might crucially depend on the amount of K available during PDT.

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APA:

Malitckaya, M., Kunze, T., Komsa, H.-P., Havu, V., Handick, E., Wilks, R.G.,... Puska, M.J. (2019). Alkali Postdeposition Treatment-Induced Changes of the Chemical and Electronic Structure of Cu(In,Ga)Se2Thin-Film Solar Cell Absorbers: A First-Principle Perspective. ACS Applied Materials and Interfaces, 11(3), 3024-3033. https://dx.doi.org/10.1021/acsami.8b18216

MLA:

Malitckaya, Maria, et al. "Alkali Postdeposition Treatment-Induced Changes of the Chemical and Electronic Structure of Cu(In,Ga)Se2Thin-Film Solar Cell Absorbers: A First-Principle Perspective." ACS Applied Materials and Interfaces 11.3 (2019): 3024-3033.

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