Impact of cation multiplicity on halide perovskite defect densities and solar cell voltages

0541706 - FZÚ 2022 RIV US eng J - Journal Article
Ledinský, Martin - Vlk, Aleš - Schönfeldová, Tereza - Holovský, Jakub - Aydin, E. - Dang, H.X. - Hájková, Zdeňka - Landová, Lucie - Valenta, J. - Fejfar, Antonín - De Wolf, S.
Impact of cation multiplicity on halide perovskite defect densities and solar cell voltages.
Journal of Physical Chemistry C. Roč. 124, č. 50 (2020), s. 27333-27339. ISSN 1932-7447. E-ISSN 1932-7455
R&D Projects: GA MŠMT LM2018110; GA ČR GJ17-26041Y; GA MŠMT(CZ) EF16_019/0000760
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institutional support: RVO:68378271
Keywords : optical-absorption edge * temperature-dependence * efficiency * silicon * lengths * luminescence
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 4.126, year: 2020
Method of publishing: Limited access
https://doi.org/10.1021/acs.jpcc.0c08193

Metal-halide perovskites feature very low deep-defect densities, thereby enabling high operating voltages at the solar cell level. Here, by precise extraction of their absorption spectra, we find that the low deep-defect density is unaffected when cations such as Cs+ and Rb+ are added during the perovskite synthesis. By comparing single crystals and polycrystalline thin films of methylammonium lead iodide/bromide, we find these defects to be predominantly localized at surfaces and grain boundaries. Furthermore, generally, for the most important photovoltaic materials, we demonstrate a strong correlation between their Urbach energy and open-circuit voltage deficiency at the solar cell level. Through external quantum yield photoluminescence efficiency measurements, we explain these results as a consequence of nonradiative open-circuit voltage losses in the solar cell. Finally, we define practical power conversion efficiency limits of solar cells by taking into account the Urbach energy.
Permanent Link: http://hdl.handle.net/11104/0319236