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.
After demonstration of a 23% power conversion efficiency, a high operational stability is the next most important scientific and technological challenge in perovskite solar cells (PSCs). A potential failure mechanism is tied to a bias‐induced ion migration, which causes current–voltage hysteresis and a decay in the device performance over time. Herein, alkali salts are shown to mitigate hysteresis and stabilize device performance in n‐i‐p hybrid planar PSCs. Different alkali salts of potassium chloride, iodide, and nitrate as well as sodium chloride and iodide are deposited from aqueous solution onto the n‐type contact, based on SnO2, prior to deposition of the perovskite absorber Cs0.05(FA0.83MA0.17)0.95Pb(I0.83Br0.17)3. Introduction of potassium‐based alkali salts suppresses the current–voltage hysteresis and stabilizes the operational device stability at the maximum power point. This is attributed to the suppression of hole trapping at the n‐type selective transport layer (SnO2)/perovskite interface observed by surface photovoltage spectroscopy, which is interpreted to reduce interfacial recombination and improve charge carrier extraction. The best and most stable performance of 19% is achieved using potassium nitrate as the interface modifier. Devices with higher and more stable performance exhibit substantially lower current transients, analyzed during maximum power point tracking.
Nonradiative losses in semiconductors are related to defects. At cryogenic temperatures, defect-related photoluminescence (PL) at energies lower than the band-edge PL is observed in methylammonium lead triiodide perovskite. We applied multispectral PL imaging to samples prepared by two different procedures and exhibiting 1 order of magnitude different PL quantum yield (PLQY). The high-PLQY sample showed concentration of the emitting defect sites around 10 12 −10 13 cm −3 . No correlation between PLQY and the relative intensity of the defect emission was found when micrometer-sized local regions of the same sample were compared. However, a clear positive correlation between the lower PLQY and higher defect emission was observed when two preparation methods were contrasted. Therefore, although the emissive defects are not connected directly with the nonradiative centers and may be spatially separated at the nano scale, chemical processes during the perovskite synthesis promote/prevent formation of both types of defects at the same time.
We report on the fabrication and optimization of Cs0.05FA0.79MA0.16Pb(Br0.17I0.83)3 perovskite solar cells from inks containing the polymer PTB7 as an additive, comparing spin-coating and inkjet printing as deposition methods. Spin-coated devices exhibited a maximum power conversion efficiency of 17.75% but showed little difference between samples with and without the polymer ink additive. For inkjet-printed devices, the combined optimization of printing parameters and the amount of the polymer additive in the precursor ink enabled a perovskite layer with increased quality. In comparison, devices with added PTB7 improved the power conversion efficiency to 10.35% as compared to 8.0% for cells prepared without the polymer additive. The effect is attributed to the modified crystallization dynamics of the perovskite layer by the PTB7 addition after inkjet printing and improved quality of the resulting perovskite layers. We found that the effect of the polymer additive on film formation in spin-coated samples was obscured when using an antisolvent drip, but the incorporation of PTB7 has a positive effect on the opto-electronic quality of thin films, indicated by the increased grain size and the photoluminescence quantum yield. Our results emphasize the technological potential of polymer additives in perovskite precursor inks when using scalable manufacturing processes, such as inkjet printing, where the control and induction of controlled crystallization are more difficult to implement by additional quenching steps.
Record performance Metal-Halide Perovskite (MHP) based solar cells have been achieved by incremental optimization of deposition procedures based on spin-coating. We here provide unprecedented insight into the formation process of MHP thin films of the “triple cation” (Cs,MA,FA)Pb(Br,I)3 perovskite from multi-modal in-situ optical process monitoring during spin-coating and annealing. This report details small-footprint fiber-optics based optical spectroscopy setup that enables monitoring of thin-film formation processes by UV-Vis reflectance and photoluminescence spectroscopy with a sub-second time resolution. Complementary information can be obtained from optical features during different stages of film formation: 1) During the first, flow regime dominated, stage of spin-coating, the wet-film thinning can be analyzed from UV-Vis interference, 2) the onset of bulk perovskite formation is clearly observed from the evolution of the semiconductor absorption edge, and 3) Photoluminescence (PL) measurements provide complementary information on nucleation and growth processes. We here provide a comprehensive picture that rationalizes the conditions to obtain a high quality “triple cation” perovskite thin-film during spin-coating and subsequent annealing.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.