Crystallization Regulation and Lead Leakage Prevention Simultaneously for High-Performance CsPbI2Br Perovskite Solar Cells.

All-inorganic CsPbI2Br perovskite is striking as a result of the reasonable band gap and thermal stability. However, the notorious air instability, unsatisfactory conversion efficiencies, and toxic water-soluble Pb2+ ions have greatly limited the further development of CsPbI2Br-based devices. Herein, a facile strategy is developed to prepare efficient and air-stable CsPbI2Br-based perovskite solar cells (PSCs) with in situ lead leakage protection. With the introduction of 2,2'-dihydroxy-4,4'-dimethoxy-5,5'-disulfobenzophenone disodium salt (BP-9) into the CsPbI2Br precursor solution, the crystallization of perovskite can be regulated at a reduced trap density, the uncoordinated Pb2+ ions and electron-rich defects in the structure can be passivated to suppress non-radiative recombination, and the energy level arrangement can be optimized to improve charge carrier transport. Consequently, the optimized PSC achieved a championship efficiency of 17.11%, accompanied by negligible J-V hysteresis and remarkably improved air stability. More importantly, the strong chelation of BP-9 with water-soluble Pb2+ ions minimizes the leakage of toxic lead in the perovskite structure.

Multifunctional anthraquinone-sulfonic potassium salts passivate the buried interface for efficient and stable planar perovskite solar cells.

SnO2-based planar perovskite solar cells (PSCs) are considered as potential photovoltaic candidates due to their simple structures and cost-effective preparation processes. However, the extensive defects accumulated at the buried interface between perovskite and SnO2 greatly hinder the further improvement of PSC efficiency and stability. Herein, the potassium salt of anthraquinone-1,8-disulfonate (ASPS) is used as a novel multifunctional interfacial modifier to improve the carrier transport performance at the buried interface and optimize the quality of the upper perovskite light absorber layer (PVK) in PSCs. Owing to the synergistic effect of sulfonic acid groups, carbonyl groups and potassium ions in ASPS, the accumulated defects at the buried interface are passivated, the energy level arrangement of the interface is optimized, and the crystalline quality and optoelectronic properties of the PVK films are improved. As a result, the power conversion efficiency (PCE) improved significantly from 21.36% for the controlled device to 23.96% for the ASPS-modified device. Furthermore, the unencapsulated ASPS-modified device also exhibited better storage stability and thermal stability than the controlled device.

High-Efficiency CsPbI2Br Perovskite Solar Cells with over 83% Fill Factor by Synergistic Effects of a Multifunctional Additive.

All-inorganic CsPbI2Br with outstanding thermal stability and excellent photoelectric properties is considered as a promising candidate for photovoltaic applications. However, the efficiency of CsPbI2Br perovskite solar cells (PSCs) is still much lower than that of their organic-inorganic hybrid counterparts or CsPbI3-based devices. Herein, we obtained an optimized CsPbI2Br PSC (0.09 cm2) with a champion efficiency of 17.38% and a record fill factor of 83.6% by introducing potassium anthraquinone-1,8-disulfonate (DAD) in the precursor solution. The synergistic effect between the electronegative functional groups and K+ ions in the DAD structure can not only effectively regulate the crystallization growth process to improve the crystalline quality and stability of photo-active CsPbI2Br but also optimize the energy level alignment and passivate the defects to improve the carrier transport properties. The efficiency of the corresponding large-area device (5 cm × 5 cm with an active area of 19.25 cm2) reached 13.20%. Moreover, the optimized CsPbI2Br PSC exhibited negligible hysteresis and enhanced long-term storage stability as well as thermal stability. Our method produces more stable photo-active CsPbI2Br with excellent photoelectric properties for industrial applications or perovskite/silicon tandem cells.

Water-soluble phosphate-pillar[5]arene (WPP5)-based artificial light-harvesting system for photocatalytic cross-coupling dehydrogenation.

A novel water-soluble phosphate-pillar[5]arene (WPP5)-based artificial light-harvesting system (LHS) was successfully fabricated through the supramolecular assembly of phenyl-pyridyl-acrylonitrile derivative (PBT), WPP5, and organic pigment Eosin Y (ESY). Initially, after host-guest interaction, WPP5 could bind well with PBT and form WPP5 âŠƒ PBT complexes in water, which further assembled into WPP5 âŠƒ PBT nanoparticles. WPP5 âŠƒ PBT nanoparticles performed an outstanding aggregation-induced emission (AIE) capability because of the J-aggregates of PBT in WPP5 âŠƒ PBT nanoparticles, which were appropriate as fluorescence resonance energy transfer (FRET) donors for artificial light-harvesting. Moreover, due to the emission region of WPP5 âŠƒ PBT overlapped well with the UV-Vis absorption of ESY, the energy of WPP5 âŠƒ PBT (donor) could be significantly transferred to ESY (acceptor) via FRET process in WPP5 âŠƒ PBT-ESY nanoparticles. Notably, the antenna effect (AEWPP5⊃PBT-ESY) of WPP5 âŠƒ PBT-ESY LHS was determined to be 30.3, which was much higher than that of recent artificial LHSs for photocatalytic cross-coupling dehydrogenation (CCD) reactions, suggesting a potential application in photocatalytic reaction. Furthermore, through the energy transfer from PBT to ESY, the absolute fluorescence quantum yields performed a remarkable increase from 14.4% (for WPP5 âŠƒ PBT) to 35.7% (for WPP5 âŠƒ PBT-ESY), further confirming their FRET processes in WPP5 âŠƒ PBT-ESY LHS. Subsequently, in order to output the harvested energy for catalytic reactions, WPP5 âŠƒ PBT-ESY LHSs were used as photosensitizers to catalyze the CCD reaction of benzothiazole and diphenylphosphine oxide. Compared to free ESY group (21%), a significant cross-coupling yield of 75% in WPP5 âŠƒ PBT-ESY LHS was observed, because more UV region energy of PBT was transferred to ESY for CCD reaction, which suggested more potential in improving the catalytic activity of organic pigment photosensitizers in aqueous systems.

A multifunctional chemical linker in a buried interface for stable and efficient planar perovskite solar cells.

The buried interface between a perovskite (PVK) light absorbing layer and an electron transport layer (ETL) plays an utmost important role in further improving the efficiency and stability of planar perovskite solar cells (PSCs). The interfacial properties greatly affect charge transport, perovskite crystal growth, and device stability. Herein, a variable structure broad-spectrum UV-284 absorber agent 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (HMBS) is introduced into PSCs based on SnO2 ETLs as an efficient multifunctional chemical linker to modify the buried interface properties. HMBS used to modify SnO2 can simultaneously suppress the surface trap states of ETLs, optimize the ETL/PVK interface energy level arrangement, and improve the crystallization quality of the upper perovskite films. Meanwhile, as an efficient UV absorber, HMBS can also greatly reduce the damage caused by UV light to perovskite films and thus improve the stability of devices. Consequently, HMBS-modified PSCs exhibit champion efficiencies of 23.42% (0.09 cm2) and 20.63% (1.00 cm2) along with remarkably enhanced UV stability. This work emphasizes the importance of appropriate interface treatment strategies for buried interface modification and provides an effective method for fabricating efficient and UV resistant perovskite photovoltaic devices.

Dual Functions of Performance Improvement and Lead Leakage Mitigation of Perovskite Solar Cells Enabled by Phenylbenzimidazole Sulfonic Acid.

With the continuous improvement of performance of lead-based perovskite solar cells (PSCs), the potential harm of water-soluble lead ion (Pb2+ ) to environment and public health is emerging as a major obstacle to their commercialization. Herein, an amphoteric phenylbenzimidazole sulfonic acid (PBSA) that is almost insoluble in water is added to the perovskite precursor to simultaneously regulate crystallization growth, passivate defects, and mitigate lead leakage of high-performance PSCs. Through systematic research, it is found that PBSA can not only regulate the crystallization of perovskite grains to form the film, but also passivate the defects of annealed films mainly due to the strong interaction between the functional groups in PBSA and Pb2+ , which greatly improves the crystallinity and stability of perovskite films. Consequently, the highest power conversion efficiency of 23.27% is achieved in 0.09 cm2 devices and 15.31% is obtained for large-area modules with an aperture area of 19.32 cm2 , along with negligible hysteresis and improved stability. Moreover, the leakage of lead ions from unpackaged devices is effectively prevented owing to the strong coupling between PBSA molecules and water-soluble Pb2+ to form insoluble complexes in water, which is of great significance to promote the application of optoelectronic devices based on lead-based perovskite materials.

Tribological Properties and Electrification Performance of Patterned Surface for Sliding-Mode Triboelectric Nanogenerator.

The triboelectric nanogenerator (TENG) can be used to transform kinetic energy into electricity based on the triboelectric effect and electrostatic induction. In most cases, the micro-/nanostructures are introduced on the polymer surface of sliding-mode TENG, but their effectiveness on electrical output as well as durability of the device are really ambiguous. Little research has been devoted to investigating the relationship between the tribological properties and electrical performance of TENG with a patterned surface so far. In this paper, the pillar arrays are fabricated through lithography, deep reactive ion etching, and replication techniques and a test platform for both tribological and electrical performance for sliding-mode TENG is constructed as well. Then, the effects of the pillar pitch on the coefficient of friction, mass loss, and open-circuit voltage are investigated experimentally. The reported results suggest that the open-circuit voltage has a clear dependence on the sliding distance of sliding-mode TENG with a certain patterned surface. Initially, the open-circuit voltage increases with the increasing sliding distance due to the increment of the contact area. Then, the open-circuit voltage diminishes with the increasing sliding distance because of the transfer of the material with negative charges from polyimide film to Cu surface. Finally, the open-circuit voltage remains almost steady with the increasing sliding distance, because the number of negatively charged wear debris of polyimide on the Cu surface is almost constant during this time. On the other hand, with the increment of the pillar pitch, the average coefficient of friction is found to be decreased, whereas the mass loss of the polymer film increases. The maximum values of the open-circuit voltage and the steady-state open-circuit voltage decrease with the increasing pillar pitch.

Recent advances in one-dimensional halide perovskites for optoelectronic applications.

Metal-halide perovskites have emerged as efficient, low-cost energy materials owing to their remarkable optoelectronic properties. In particular, the dimensionality and morphology of crystallites may have a striking influence on their chemical and physical properties and therefore affect their optoelectronic applications. One-dimensional halide perovskites have superior carrier transportation in one dimension, high crystalline quality, and consequently, high quantum efficiencies and long carrier diffusion lengths, which are important for the performance of perovskite-based nanoscale optoelectronic and photonic devices. In this review, we highlight recent advances in the synthesis of one-dimensional halide perovskites and their unique properties as well as their novel optoelectronic applications. This review aims to provide an overview of the achievements in synthesis techniques and nanoscale optoelectronic applications based on one-dimensional perovskite nanocrystals.

Glucocorticoid induces apoptosis in rat leydig cells.

The aim of the present study was to investigate whether glucocorticoid induces apoptosis in rat Leydig cells. To determine whether there are developmental differences in glucocorticoid sensitivity, Leydig cells were isolated at distinct stages of their differentiation [mesenchymal-like progenitors (PLC), immature Leydig cells (ILC), and adult Leydig cells (ALC)] from 21-, 35-, and 90-d-old Sprague Dawley rats, respectively. Glucocorticoid induction of apoptosis was evaluated after both in vitro and in vivo exposures. In the first set of experiments, PLC, ILC, and ALC were treated with 100 nM corticosterone (CORT) for either 4 or 24 h in vitro and then assessed for labeling with the apoptotic marker annexin V. PLC exposed to CORT had levels of annexin V-fluorescein isothiocyanate labeling that were unchanged relative to control values at both time points (P > 0.05). In contrast, CORT-treated ILC and ALC had increased frequencies of apoptosis: in ALC, a 22.1 +/- 1.7% incidence after 4 h and 30.5 +/- 2.3% after 24 h compared with 7.4 +/- 0.8% in untreated controls (P < 0.05). Similar trends were observed for ILC. Ultrastructural analysis confirmed that the increase in annexin V labeling was associated with characteristic signs of apoptosis, including nuclear fragmentation and formation of apoptotic bodies. A second line of experiments examined whether apoptosis was evident in purified Leydig cells after administration of CORT in vivo. Male rats were subjected to bilateral adrenalectomy and were treated with CORT by ip injection twice daily at doses ranging from 2.5-7.5 mg/100 g BW starting 3 d after surgery. The frequency of Leydig cell apoptosis was measured at 12, 24, 48, and 72 h after the first injection. Administration of the 2.5-mg dose raised circulating CORT 5-10 times above normal basal concentrations, and LH levels sampled at these times were not altered in the treated animals. Increased Leydig cell apoptosis was measurable after 24 h of treatment, with an incidence of 21.1 +/- 1.8% in ALC compared with 5.7 +/- 0.8% in untreated controls (P < 0.05). Sharp reductions in immunocytochemical staining intensity were observed in the treated animals for a Leydig cell marker, 11beta-hydroxysteroid dehydrogenase, which occurred concurrently with decreased serum T levels. This was consistent with the hypothesis that CORT-mediated induction of apoptosis leads to declines in Leydig cell numbers, thereby affecting T production. These results suggest that excessive exposure to CORT initiates apoptosis in rat Leydig cells, potentially contributing to suppression of circulating T levels during stress and other conditions in which glucocorticoid concentrations are elevated.