Search

Cs2AgBiBr6, as a benchmark lead‐free double perovskite, has emerged as a promising alternative to lead‐based perovskites because of its high stability, non‐toxicity, exceptional optoelectronic properties, and multifunctionality. To encourage further research on Cs2AgBiBr6 and its broad applications, in this review, its fundamental properties including the structure‐property relation, synthesis, stability, origin of absorption and photoluminescence, electron‐phonon coupling, role of defects, charge carrier dynamics, and bandgap modulation are comprehensively emphasized. The recent progress on the wide applications including solar cells, light/X‐ray detectors, and ferroelectric/magnetic devices are highlighted. Moreover, the challenges of Cs2AgBiBr6 materials and related applications are discussed and perspectives are provided for guiding the future development of this research area. [ABSTRACT FROM AUTHOR]

Nickel oxide (NiOx) is desirable hole selective material (HSMs) for perovskite photovoltaics because of the characteristic in stability and low cost. However, they deliver limited open‐circuit voltage (VOC) compared to some organic HSMs. As it is known, the performance of perovskite solar cells is predominantly limited by trap‐assisted non‐radiative recombination at the perovskite/hole‐selective layer interfaces. A typical lithium‐doping strategy leads to the valence‐band maximum shift and the electronic levels of NiOx can be tuned robustly to match perovskite active layer in perovskite solar cells. More critically, carrier dynamics studies demonstrate another critical PN4N interlayer strategy reduced interfacial density of defect sites and trap‐assisted recombination. These merits contribute coordinately to lower energy loss across the perovskite/NiOx interface and facilitate charge transport process through the relevant interface, yielding VOC values increase to 1.14 V and power conversion efficiencies over 20%. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO2) offers its advantages in widespread applications that require efficient carrier transport. However, the usages of SnO2 in organic solar cells are hindered because of dangling bonds on the surface of SnO2. Herein, PFN‐Br as an interfacial layer to tailor the work function of SnO2 is adopted, making it an ideal candidate for interfacial material in organic electronics. Meanwhile, such an efficient SnO2/PFN‐Br electron transport layer (ETL) can also be applied to perovskite devices and achieve competitive efficiency. To eliminate current–voltage hysteresis and improve poor thermodynamic stability of perovskite solar cells (PSCs), 5 mol% of guanidinium iodide (GAI) into the (MA)x(FA)1 − xPbI3 precursor solution is incorporated, enabling the formation of triple‐cation perovskite films with excellent optoelectronic quality and stability. The combination of an SnO2/PFN‐Br ETL and GAI doping strategy finally delivers power conversion efficiencies over 21% and negligible current–voltage hysteresis in planar PSCs. These improvements arise from the strong hydrogen bonding caused by the incorporation of GA+. It can stiffen the inorganic Pb–I lattice of the unit cell and restrain the formation of iodine vacancies defects. Moreover, the strong hydrogen bonding can immobilize iodide ion and thus enhance the thermal stability of the corresponding device. [ABSTRACT FROM AUTHOR]

Perovskite Solar Cells: In Situ Defect Passivation with Silica Oligomer for Enhanced Performance and Stability of Perovskite Solar Cells (Adv. In article number 1901716, Hongwei Lei, Song Zhang, Zuojun Tan, and co-workers report a novel and efficient perovskite defect passivation strategy using silica oligomer. Silica oligomer PA can enlarge perovskite grain sizes, prolong carrier lifetime, enhance charge carrier dynamics and reduce trap state densities, resulting in highly efficient PVSCs with good humid and thermal stability. [Extracted from the article]

Perovskite solar cells (PVSCs) have achieved excellent power conversion efficiency (PCE) but still suffer from instability issues. Defect passivation is an important route to simultaneously increase the efficiency and stability of PVSCs. Here, a strategy of incorporating silica oligomer in perovskite films for surface and grain boundary defect passivation is reported. Silica oligomer passivation agent (PA) is in situ formed through hydrolysis and condensation reaction of tetraethyl orthosilicate additive in perovskite precursor. The passivation mechanism is elucidated by density functional theory calculation, revealing stable chelating interaction and hydrogen bond interaction between PA and perovskite. Spectroscopic and electrical characterizations demonstrate that silica oligomer can enlarge grain sizes, prolong carrier lifetime, enhance charge carrier dynamics, and reduce trap state densities in perovskite films. Planar PVSCs with passivation achieve a highly improved PCE of 19.64% with a stabilized efficiency of 18.81%. More importantly, unencapsulated perovskite devices with passivation retain nearly 90% of original efficiency after 1000 h storage under ambient condition and sustained 87% of initial performance after high‐temperature (120 °C) thermal accelerated aging, showing highly enhanced moisture and thermal stability. Therefore, the present study provides a pathway to the future design and optimization of PVSCs with higher efficiency and greater stability. [ABSTRACT FROM AUTHOR]

Antimony chalcogenides such as Sb2S3, Sb2Se3, and Sb2(SxSe1−x)3 have emerged as very promising alternative solar absorber materials due to their high stability, abundant elemental storage, nontoxicity, low‐cost, suitable tunable bandgap, and high absorption coefficient. Remarkable achievements have been made in antimony chalcogenide solar cells in the past few decades, with the power conversion efficiency (PCE) currently reaching 9.2%, which is close to the PCE level required for industrial applications. To facilitate the realization of highly efficient antimony chalcogenide solar cells in the future, a comprehensive review of antimony chalcogenide‐based materials and photovoltaic devices is presented. First, the fundamental physical properties and preparation methods of antimony chalcogenide‐based materials are outlined, and then, notable recent developments in antimony chalcogenide‐based photovoltaic devices with various architectures are highlighted. Finally, the most prominent limitations are described, and approaches to achieving remarkable advances in antimony chalcogenide solar cells in the future are provided. [ABSTRACT FROM AUTHOR]