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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]

Sb2S3 solar cells are lagging behind conventional thin-film solar cells such as silicon solar cells and cadmium telluride solar cells in the power conversion efficiency (PCE). One of the most prominent problems is that the carrier concentration of Sb2S3 is relatively low. In order to increase the carrier concentration, elemental Cu was doped into Sb2S3 film by radio-frequency (RF) magnetron sputtering. We proved that Cu was doped into Sb2S3 films and mainly anchored with sulfur in the form of copper chalcogenide species at the surface and grain boundaries of Sb2S3. The doping of Cu essentially affects the physical and electrical properties of RF-sputtered Sb2S3 films such as the optical band gap, crystallinity, chemical composition, morphology, and carrier concentration. Specially, the electronic carrier concentration is remarkably increased from 6.28 × 109 to 6.06 × 1010 cm−3 and the Fermi level is also significantly uplifted after prudent doping with Cu. Planar solar cells based on RF-sputtered Cu-doped Sb2S3 absorber deliver an increased PCE of 1.13% and show good stability. This research proves that doping of Cu is an alternative and effective way to improve the electronic property of Sb2S3 films and enhance the performance of Sb2S3 solar cells. [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]

Perovskite solar cells have developed rapidly in recent years as the third generation solar cells. In spite of the great improvement achieved, there still exist some issues such as undesired hysteresis and indispensable high temperature process. In this work, bulk heterojunction perovskite-phenyl-C 61 -butyric acid methyl ester solar cells have been prepared to diminish hysteresis using a facile two step spin-coating method. Furthermore, high quality tin oxide films are fabricated using pulse laser deposition technique at room temperature without any annealing procedure. The as fabricated tin oxide film is successfully applied in bulk heterojunction perovskite solar cells as a hole blocking layer. Bulk heterojunction devices based on room temperature tin oxide exhibit almost hysteresis-free characteristics with power conversion efficiency of 17.29% and 14.0% on rigid and flexible substrates, respectively. [ABSTRACT FROM AUTHOR]

Ternary oxides Fe 2-x Mg x O 3 is introduced to passivate the perovskite/SnO 2 QDs interface, trigger the heterogeneous nucleation for uniform perovskite films, and increase the interface contact for the rapid electron transfer. Consequently, the corresponding perovskite solar cell achieves a champion efficiency over 21%. [Display omitted] • Fe 2-x Mg x O 3 is introduced to passivate the perovskite/SnO 2 interface. • The interaction between perovskite and Fe 2-x Mg x O 3 triggers a heterogeneous nucleation. • Flocculent Fe 2-x Mg x O 3 increase the contact with perovskite for electron transfer. • The interaction between Fe 2-x Mg x O 3 and SnO 2 QD passivates the defects. • Fe 1.84 Mg 0.16O 3 -based PSC achieves a champion efficiency over 21% with negligible J–V hysteresis. Interface function material has been widely used to reduce interfacial potential barrier for enhanced charge-dynamics and photovoltaic properties of perovskite solar cells (PSCs). Herein, ternary oxides Fe 2-x Mg x O 3 are introduced to passivate the perovskite/SnO 2 quantum dots (QDs) interface. The interaction between perovskite and Fe 2-x Mg x O 3 could trigger a heterogeneous nucleation for the uniform perovskite photoactive layer. The flocculent Fe 2-x Mg x O 3 also increase the interface contact with perovskite enabling more transferring channel of electron, and decrease the interface-defects with smaller the energy level offset at this interface. Such oxide bridges between perovskite and SnO 2 QD could effectively enhance electron transfer. Consequently, a Fe 1.84 Mg 0.16 O 3 -based PSC is achieved with a champion efficiency over 21% and negligible J–V hysteresis. [ABSTRACT FROM AUTHOR]