Charge transport in mixed metal halide perovskite semiconductors
Nature Materials Springer Nature 22:2 (2023) 216-224
Charge transport in mixed metal halide perovskite semiconductors
Nature Materials 22, 216–224 (2023)
Abstract:
Investigation of the inherent field-driven charge transport behaviour of three-dimensional lead halide perovskites has largely remained challenging, owing to undesirable ionic migration effects near room temperature and dipolar disorder instabilities prevalent specifically in methylammonium-and-lead-based high-performing three-dimensional perovskite compositions. Here, we address both these challenges and demonstrate that field-effect transistors based on methylammonium-free, mixed metal (Pb/Sn) perovskite compositions do not suffer from ion migration effects as notably as their pure-Pb counterparts and reliably exhibit hysteresis-free p-type transport with a mobility reaching 5.4 cm2 V–1 s−1. The reduced ion migration is visualized through photoluminescence microscopy under bias and is manifested as an activated temperature dependence of the field-effect mobility with a low activation energy (~48 meV) consistent with the presence of the shallow defects present in these materials. An understanding of the long-range electronic charge transport in these inherently doped mixed metal halide perovskites will contribute immensely towards high-performance optoelectronic devices.
Tunable Multiband Halide Perovskite Tandem Photodetectors with Switchable Response
ACS Photonics 9, 3958–3966 (2022)
Abstract:
Photodetectors with multiple spectral response bands have shown promise to improve imaging and communications through the switchable detection of different photon energies. However, demonstrations to date have been limited to only two bands and lack capability for fast switching in situ. Here, we exploit the band gap tunability and capability of all-perovskite tandem solar cells to demonstrate a new device concept realizing four spectral bands of response from a single multijunction device, with fast, optically controlled switching between the bands. The response to monochromatic light is highly selective and narrowband without the need for additional filters and switches to broader response bands on applying bias light. Sensitive photodetection above 6 × 1011 Jones is demonstrated in all modes, with rapid switching response times of <250 ns. We demonstrate proof of principle on how the manipulation of the modular multiband detector response through light conditions enables diverse applications in optical communications with secure encryption.
Impact of the Addition of Tin on the Charge Carrier Dynamics of Metal Halide Perovskites
47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz), 2022
Abstract:
The gradual partial to full introduction of lead into pure tin films has been shown to enhance the stability and performance of tin-based perovskite thin films. However, how its influences the charge carrier recombination dynamics is yet to be studied. Here, the impact of the addition of tin on the charge carrier recombination dynamics is studied. We elucidate an enhancement in the charge carrier lifetime and hence reduction in monomolecular recombination with the introduction of higher lead ratio.
An open-access database and analysis tool for perovskite solar cells based on the FAIR data principles
Nature Energy 7, 107–115 (2022)
Abstract:
Large datasets are now ubiquitous as technology enables higher-throughput experiments, but rarely can a research field truly benefit from the research data generated due to inconsistent formatting, undocumented storage or improper dissemination. Here we extract all the meaningful device data from peer-reviewed papers on metal-halide perovskite solar cells published so far and make them available in a database. We collect data from over 42,400 photovoltaic devices with up to 100 parameters per device. We then develop open-source and accessible procedures to analyse the data, providing examples of insights that can be gleaned from the analysis of a large dataset. The database, graphics and analysis tools are made available to the community and will continue to evolve as an open-source initiative. This approach of extensively capturing the progress of an entire field, including sorting, interactive exploration and graphical representation of the data, will be applicable to many fields in materials science, engineering and biosciences.