Correction to "Trace Water in Lead Iodide Affecting Perovskite Crystal Nucleation Limits the Performance of Perovskite Solar Cells".

Advanced materials (Deerfield Beach, Fla.) 36:23 (2024) e2403227

Authors:

Renjun Guo, Qiu Xiong, Aleksander Ulatowski, Saisai Li, Zijin Ding, Tianxiao Xiao, Suzhe Liang, Julian E Heger, Tianfu Guan, Xinyu Jiang, Kun Sun, Lennart K Reb, Manuel A Reus, Andrei Chumakov, Matthias Schwartzkopf, Minjian Yuan, Yi Hou, Stephan V Roth, Laura M Herz, Peng Gao, Peter Müller-Buschbaum

Bandgap-universal passivation enables stable perovskite solar cells with low photovoltage loss

Science American Association for the Advancement of Science 384:6697 (2024) 767-775

Authors:

Yen-Hung Lin, Vikram, Fengning Yang, Xue-Li Cao, Akash Dasgupta, Robert DJ Oliver, Aleksander M Ulatowski, Melissa M McCarthy, Xinyi Shen, Qimu Yuan, M Greyson Christoforo, Fion Sze Yan Yeung, Michael B Johnston, Nakita K Noel, Laura M Herz, M Saiful Islam, Henry J Snaith

Abstract:

The efficiency and longevity of metal-halide perovskite solar cells are typically dictated by nonradiative defect-mediated charge recombination. In this work, we demonstrate a vapor-based amino-silane passivation that reduces photovoltage deficits to around 100 millivolts (>90% of the thermodynamic limit) in perovskite solar cells of bandgaps between 1.6 and 1.8 electron volts, which is crucial for tandem applications. A primary-, secondary-, or tertiary-amino–silane alone negatively or barely affected perovskite crystallinity and charge transport, but amino-silanes that incorporate primary and secondary amines yield up to a 60-fold increase in photoluminescence quantum yield and preserve long-range conduction. Amino-silane–treated devices retained 95% power conversion efficiency for more than 1500 hours under full-spectrum sunlight at 85°C and open-circuit conditions in ambient air with a relative humidity of 50 to 60%.

The Role of Chemical Composition in Determining the Charge‐Carrier Dynamics in (AgI)x(BiI3)y Rudorffites

Advanced Functional Materials Wiley (2024)

Authors:

Snigdha Lal, Marcello Righetto, Benjamin WJ Putland, Harry C Sansom, Silvia G Motti, Heon Jin, Michael B Johnston, Henry J Snaith, Laura M Herz

Disentangling the effects of structure and lone-pair electrons in the lattice dynamics of halide perovskites.

Nature communications 15:1 (2024) 4184

Authors:

Sebastián Caicedo-Dávila, Adi Cohen, Silvia G Motti, Masahiko Isobe, Kyle M McCall, Manuel Grumet, Maksym V Kovalenko, Omer Yaffe, Laura M Herz, Douglas H Fabini, David A Egger

Abstract:

Halide perovskites show great optoelectronic performance, but their favorable properties are paired with unusually strong anharmonicity. It was proposed that this combination derives from the ns2 electron configuration of octahedral cations and associated pseudo-Jahn-Teller effect. We show that such cations are not a prerequisite for the strong anharmonicity and low-energy lattice dynamics encountered in these materials. We combine X-ray diffraction, infrared and Raman spectroscopies, and molecular dynamics to contrast the lattice dynamics of CsSrBr3 with those of CsPbBr3, two compounds that are structurally similar but with the former lacking ns2 cations with the propensity to form electron lone pairs. We exploit low-frequency diffusive Raman scattering, nominally symmetry-forbidden in the cubic phase, as a fingerprint of anharmonicity and reveal that low-frequency tilting occurs irrespective of octahedral cation electron configuration. This highlights the role of structure in perovskite lattice dynamics, providing design rules for the emerging class of soft perovskite semiconductors.

Unraveling Loss Mechanisms Arising from Energy‐Level Misalignment between Metal Halide Perovskites and Hole Transport Layers

Advanced Functional Materials Wiley (2024)

Authors:

Jae Eun Lee, Silvia G Motti, Robert DJ Oliver, Siyu Yan, Henry J Snaith, Michael B Johnston, Laura M Herz

Abstract:

<jats:title>Abstract</jats:title><jats:p>Metal halide perovskites are promising light absorbers for multijunction photovoltaic applications because of their remarkable bandgap tunability, achieved through compositional mixing on the halide site. However, poor energy‐level alignment at the interface between wide‐bandgap mixed‐halide perovskites and charge‐extraction layers still causes significant losses in solar‐cell performance. Here, the origin of such losses is investigated, focusing on the energy‐level misalignment between the valence band maximum and the highest occupied molecular orbital (HOMO) for a commonly employed combination, FA<jats:sub>0.83</jats:sub>Cs<jats:sub>0.17</jats:sub>Pb(I<jats:sub>1‐x</jats:sub>Br<jats:sub>x</jats:sub>)<jats:sub>3</jats:sub> with bromide content x ranging from 0 to 1, and poly[bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine] (PTAA). A combination of time‐resolved photoluminescence spectroscopy and numerical modeling of charge‐carrier dynamics reveals that open‐circuit voltage (V<jats:sub>OC</jats:sub>) losses associated with a rising energy‐level misalignment derive from increasing accumulation of holes in the HOMO of PTAA, which then subsequently recombine non‐radiatively across the interface via interfacial defects. Simulations assuming an ideal choice of hole‐transport material to pair with FA<jats:sub>0.83</jats:sub>Cs<jats:sub>0.17</jats:sub>Pb(I<jats:sub>1‐x</jats:sub>Br<jats:sub>x</jats:sub>)<jats:sub>3</jats:sub> show that such V<jats:sub>OC</jats:sub> losses originating from energy‐level misalignment can be reduced by up to 70 mV. These findings highlight the urgent need for tailored charge‐extraction materials exhibiting improved energy‐level alignment with wide‐bandgap mixed‐halide perovskites to enable solar cells with improved power conversion efficiencies.</jats:p>