TY  - JOUR
A1  - Stolterfoht, Martin
A1  - Grischek, Max
A1  - Caprioglio, Pietro
A1  - Wolff, Christian Michael
A1  - Gutierrez-Partida, Emilio
A1  - Peña-Camargo, Francisco
A1  - Rothhardt, Daniel
A1  - Zhang, Shanshan
A1  - Raoufi, Meysam
A1  - Wolansky, Jakob
A1  - Abdi-Jalebi, Mojtaba
A1  - Stranks, Samuel D.
A1  - Albrecht, Steve
A1  - Kirchartz, Thomas
A1  - Neher, Dieter
T1  - How to quantify the efficiency potential of neat perovskite films
BT  - Perovskite semiconductors with an implied efficiency exceeding 28%
JF  - Advanced Materials
N2  - Perovskite photovoltaic (PV) cells have demonstrated power conversion efficiencies (PCE) that are close to those of monocrystalline silicon cells; however, in contrast to silicon PV, perovskites are not limited by Auger recombination under 1-sun illumination. Nevertheless, compared to GaAs and monocrystalline silicon PV, perovskite cells have significantly lower fill factors due to a combination of resistive and non-radiative recombination losses. This necessitates a deeper understanding of the underlying loss mechanisms and in particular the ideality factor of the cell. By measuring the intensity dependence of the external open-circuit voltage and the internal quasi-Fermi level splitting (QFLS), the transport resistance-free efficiency of the complete cell as well as the efficiency potential of any neat perovskite film with or without attached transport layers are quantified. Moreover, intensity-dependent QFLS measurements on different perovskite compositions allows for disentangling of the impact of the interfaces and the perovskite surface on the non-radiative fill factor and open-circuit voltage loss. It is found that potassium-passivated triple cation perovskite films stand out by their exceptionally high implied PCEs > 28%, which could be achieved with ideal transport layers. Finally, strategies are presented to reduce both the ideality factor and transport losses to push the efficiency to the thermodynamic limit.
KW  - non-radiative interface recombination
KW  - perovskite solar cells
KW  - photoluminescence
Y1  - 2020
U6  - https://doi.org/10.1002/adma.202000080
SN  - 0935-9648
SN  - 1521-4095
VL  - 32
IS  - 17
SP  - 1
EP  - 10
PB  - Wiley-VCH
CY  - Weinheim
ER  -