Highly Efficient and Scalable p-i-n Perovskite Solar Cells Enabled by Poly-metallocene Interfaces.

Inverted p-i-n perovskite solar cells (PSCs) are easy to process but need improved interface characteristics with reduced energy loss to prevent efficiency drops when increasing the active photovoltaic area. Here, we report a series of poly ferrocenyl molecules that can modulate the perovskite surface enabling the construction of small- and large-area PSCs. We found that the perovskite-ferrocenyl interaction forms a hybrid complex with enhanced surface coordination strength and activated electronic states, leading to lower interfacial nonradiative recombination and charge transport resistance losses. The resulting PSCs achieve an enhanced efficiency of up to 26.08% for small-area devices and 24.51% for large-area devices (1.0208 cm2). Moreover, the large-area PSCs maintain >92% of the initial efficiency after 2000 h of continuous operation at the maximum power point under 1-sun illumination and 65 °C.

Top-Down Induced Crystallization Orientation toward Highly Efficient p-i-n Perovskite Solar Cells.

Crystallization orientation plays a crucial role in determining the performance and stability of perovskite solar cells (PVSCs), whereas effective strategies for realizing oriented perovskite crystallization is still lacking. Herein, a facile and efficient top-down strategy is reported to manipulate the crystallization orientation via treating perovskite wet film with propylamine chloride (PACl) before annealing. The PA+ ions tend to be adsorbed on the (001) facet of the perovskite surface, resulting in the reduced cleavage energy to induce (001) orientation-dominated growth of perovskite film and then reduce the temperature of phase transition, meanwhile, the penetrating Cl ions further regulate the crystallization process. As-prepared (001)-dominant perovskite films exhibit the ameliorative film homogeneity in terms of vertical and horizontal scale, leading to alleviated lattice mismatch and lowered defect density. The resultant PVSC devices deliver a champion power conversion efficiency (PCE) of 25.07% with enhanced stability, and the unencapsulated PVSC device maintains 95% of its initial PCE after 1000 h of operation at the maximum power point under simulated AM 1.5G illumination.

Deletion of the B125R gene in the African swine fever virus SY18 strain leads to an A104R frameshift mutation slightly attenuating virulence in domestic pigs.

African swine fever (ASF), caused by the ASF virus (ASFV), is a hemorrhagic and fatal viral disease that affects Eurasian wild boars and domestic pigs, posing a substantial threat to the global pig breeding industry. ASFV, a double-stranded DNA virus, possesses a large genome containing up to 160 open reading frames, most of which exhibit unknown functions. The B125R gene of ASFV, located at the 105595-105972 bp site in the ASFV-SY18 genome, remains unexplored. In this study, we discovered that B125R deletion did not affect recombinant virus rescue, nor did it hinder viral replication during the intermediate growth phase. Although the virulence of the recombinant strain harboring this deletion was attenuated, intramuscular inoculation of the recombinant virus in pigs at doses of 102 or 104 TCID50 resulted in mortality. Moreover, sequencing analysis of six recombinant strains obtained from three independent experiments consistently revealed an adenine insertion at the 47367-47375 bp site in the A104R gene due to the B125R deletion, leading to premature termination of this gene. Intriguingly, this insertion did not influence the transcription of the A104R gene between the recombinant and parental strains. Consequently, we postulate that the deletion of the B125R gene in ASFV-SY18 or other genotype II strains may marginally attenuate virulence in domestic pigs.

A quantum-chemical insight into SOMO-HOMO conversion in phosphorus-boron cation radicals.

Organic radicals exhibiting SOMO-HOMO conversion (SHC) electronic configurations have recently garnered increasing attention due to their exceptional stability and photophysical properties. In this study, we investigate two series of phosphorus-boron cation radicals based on 1,3,5-trimethylphenyl units substituted with P and B atoms, varying numbers of P-B moieties, and π-conjugation linkers. We perform quantum-chemical calculations to systematically assess the influence of chemical substituents on the SHC electronic structural features. Our computational results demonstrate that the SHC electronic configurations of the studied complexes are primarily determined by the number of P-B moieties, specifically, phosphorus-boron cation radicals with two P-B moieties as terminal groups in π-conjugation linkers, which efficiently arrange electrons to increase HOMO energies compared to corresponding radicals with only one P-B unit. Furthermore, spin density distributions change as the size of π-conjugation linkers increases. Natural bond orbital (NBO) and atoms-in-molecules (AIM) analyses reveal strong intramolecular charge transfer between P and B atoms along with other stabilized donor-acceptor interactions and significant covalent bonds between P and B atoms. Moreover, synergistic effects resulting from 1,3,5-trimethylphenyl substitutions and enlarged π-conjugation linkers containing P-B units confer excellent photophysical properties upon these studied radicals, making them potential stable radicals in optoelectronic applications.

Deleting the C84L Gene from the Virulent African Swine Fever Virus SY18 Does Not Affect Its Replication in Porcine Primary Macrophages but Reduces Its Virulence in Swine.

(1) Background: African swine fever (ASF) is a highly contagious disease that causes high pig mortality. Due to the absence of vaccines, prevention and control are relatively challenging. The pathogenic African swine fever virus (ASFV) has a complex structure and encodes over 160 proteins, many of which still need to be studied and verified for their functions. In this study, we identified one of the unknown functional genes, C84L. (2) Methods: A gene deficient strain was obtained through homologous recombination and several rounds of purification, and its replication characteristics and virulence were studied through in vitro and in vivo experiments, respectively. (3) Results: Deleting this gene from the wild-type virulent strain SY18 did not affect its replication in porcine primary macrophages but reduced its virulence in pigs. In animal experiments, we injected pigs with a 102 TCID50, 105 TCID50 deletion virus, and a 102 TCID50 wild-type strain SY18 intramuscularly. The control group pigs reached the humane endpoint on the ninth day (0/5) and were euthanized. Two pigs in the 102 TCID50(2/5) deletion virus group survived on the twenty-first day, and one in the 105 TCID50(1/5) deletion virus group survived. On the twenty-first day, the surviving pigs were euthanized, which was the end of the experiment. The necropsies of the survival group and control groups' necropsies showed that the surviving pigs' liver, spleen, lungs, kidneys, and submaxillary lymph nodes did not show significant lesions associated with the ASFV. ASFV-specific antibodies were first detected on the seventh day after immunization; (4) Conclusions: This is the first study to complete the replication and virulence functional exploration of the C84L gene of SY18. In this study, C84L gene was preliminarily found not a necessary gene for replication, gene deletion strain SY18ΔC84L has similar growth characteristics to SY18 in porcine primary alveolar macrophages. The C84L gene affects the virulence of the SY18 strain.

Molecular characterization of an outbreak-involved Bacillus anthracis strain confirms the spillover of anthrax from West Africa.

BACKGROUND: Anthrax, a zoonotic disease caused by the spore-forming bacterium Bacillus anthracis, remains a major global public health concern, especially in countries with limited resources. Sierra Leone, a West African country historically plagued by anthrax, has almost been out of report on this disease in recent decades. In this study, we described a large-scale anthrax outbreak affecting both animals and humans and attempted to characterize the pathogen using molecular techniques. METHODS: The causative agent of the animal outbreak in Port Loko District, Sierra Leone, between March and May 2022 was identified using the nanopore sequencing technique. A nationwide active surveillance was implemented from May 2022 to June 2023 to monitor the occurrence of anthrax-specific symptoms in humans. Suspected cases were subsequently verified using quantitative polymerase chain reaction. Full-genome sequencing was accomplished by combining long-read and short-read sequencing methods. Subsequent phylogenetic analysis was performed based on the full-chromosome single nucleotide polymorphisms. RESULTS: The outbreak in Port Loko District, Sierra Leone, led to the death of 233 animals between March 26th and May 16th, 2022. We ruled out the initial suspicion of Anaplasma species and successfully identified B. anthracis as the causative agent of the outbreak. As a result of the government's prompt response, out of the 49 suspected human cases identified during the one-year active surveillance, only 6 human cases tested positive, all within the first month after the official declaration of the outbreak. The phylogenetic analysis indicated that the BaSL2022 isolate responsible for the outbreak was positioned in the A.Br.153 clade within the TransEuroAsian group of B. anthracis. CONCLUSIONS: We successfully identified a large-scale anthrax outbreak in Sierra Leone. The causative isolate of B. anthracis, BaSL2022, phylogenetically bridged other lineages in A.Br.153 clade and neighboring genetic groups, A.Br.144 and A.Br.148, eventually confirming the spillover of anthrax from West Africa. Given the wide dissemination of B. anthracis spores, it is highly advisable to effectively monitor the potential reoccurrence of anthrax outbreaks and to launch campaigns to improve public awareness regarding anthrax in Sierra Leone.

Charge Management Enables Efficient Spontaneous Chromatic Adaptation Bipolar Photodetector.

Solution-processed photodetectors have emerged as promising candidates for next-generation of visible-near infrared (vis-NIR) photodetectors. This is attributed to their ease of processing, compatibility with flexible substrates, and the ability to tune their detection properties by integrating complementary photoresponsive semiconductors. However, the limited performance continues to hinder their further development, primarily influenced by the difference of charge transport properties between perovskite and organic semiconductors. In this work, a perovskite-organic bipolar photodetectors (PDs) is introduced with multispectral responsivity, achieved by effectively managing charges in perovskite and a ternary organic heterojunction. The ternary heterojunction, incorporating a designed NIR guest acceptor, exhibits a faster charge transfer rate and longer carrier diffusion length than the binary heterojunction. By achieving a more balanced carrier dynamic between the perovskite and organic components, the PD achieves a low dark current of 3.74 nA cm-2 at -0.2 V, a fast response speed of <10 µs, and a detectivity of exceeding 1012 Jones. Furthermore, a bioinspired retinotopic system for spontaneous chromatic adaptation is achieved without any optical filter. This charge management strategy opens up possibilities for surpassing the limitations of photodetection and enables the realization of high-purity, compact image sensors with exceptional spatial resolution and accurate color reproduction.

Efficient Solar-Driven Water Splitting Enabled by Perovskite Photovoltaics and a Halogen-Modulated Metal-Organic Framework Electrocatalyst.

Solar-driven water splitting powered by photovoltaics enables efficient storage of solar energy in the form of hydrogen fuel. In this work, we demonstrate efficient solar-to-hydrogen conversion using perovskite (PVK) tandem photovoltaics and a halogen-modulated metal-organic framework (MOF) electrocatalyst. By substituting tetrafluoroterephthalate (TFBDC) for terephthalic (BDC) ligands in a nickel-based MOF, we achieve a 152 mV improvement in oxygen evolution reaction (OER) overpotential at 10 mA·cm2. Through X-ray photoelectron spectroscopy (XPS), X-ray adsorption structure (XAS) analysis, theoretical simulation, and electrochemical results, we demonstrated that the introduction of fluorine atoms enhanced the intrinsic activity of Ni sites as well as the transfer property and accessibility of the MOF. Using this electrocatalyst in a bias-free photovoltaic electrochemical (PV-EC) system with a PVK/organic tandem solar cell, we achieve 6.75% solar-to-hydrogen efficiency (ηSTH). We also paired the electrocatalyst with a PVK photovoltaic module to drive water splitting at 206.7 mA with ηSTH of 10.17%.

Suppressing Oxidation at Perovskite-NiOx Interface for Efficient and Stable Tin Perovskite Solar Cells.

Inorganic nickel oxide (NiOx ) is an ideal hole transport material (HTM) for the fabrication of high-efficiency, stable, and large-area perovskite photovoltaic devices because of its low cost, stability, and ease of solution processing. However, it delivers low power conversion efficiency (PCE) in tin perovskite solar cells (TPSCs) compared to other organic HTMs. Here, the origin of hole transport barriers at the perovskite-NiOx interface is identified and a self-assembled monolayer interface modification is developed, through introducing (4-(7H-dibenzo[c,g]carbazol-7-yl)ethyl)phosphonic acid (2PADBC) into the perovskite-NiOx interface. The 2PADBC anchors undercoordinated Ni cations through phosphonic acid groups, suppressing the reaction of highly active Ni≥3+ defects with perovskites, while increasing the electron density and oxidation activation energy of Sn at the perovskite interface, reducing the interface nonradiative recombination caused by tetravalent Sn defects. The devices deliver significantly increased open-circuit voltage from 0.712 to 0.825 V, boosting the PCE to 14.19% for the small-area device and 12.05% for the large-area (1 cm2 ) device. In addition, the 2PADBC modification enhances the operational stability of NiOx -based TPSCs, maintaining more than 93% of their initial efficiency after 1000 h.

Stabilized hole-selective layer for high-performance inverted p-i-n perovskite solar cells.

P-i-n geometry perovskite solar cells (PSCs) offer simplified fabrication, greater amenability to charge extraction layers, and low-temperature processing over n-i-p counterparts. Self-assembled monolayers (SAMs) can enhance the performance of p-i-n PSCs but ultrathin SAMs can be thermally unstable. We report a thermally robust hole-selective layer comprised of nickel oxide (NiOx) nanoparticle film with a surface-anchored (4-(3,11-dimethoxy-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid (MeO-4PADBC) SAM that can improve and stabilize the NiOx/perovskite interface. The energetic alignment and favorable contact and binding between NiOx/MeO-4PADBC and perovskite reduced the voltage deficit of PSCs with various perovskite compositions and led to strong interface toughening effects under thermal stress. The resulting 1.53-electron-volt devices achieved 25.6% certified power conversion efficiency and maintained >90% of their initial efficiency after continuously operating at 65 degrees Celsius for 1200 hours under 1-sun illumination.

SY18ΔL60L: a new recombinant live attenuated African swine fever virus with protection against homologous challenge.

Introduction: African swine fever (ASF) is an acute and highly contagious disease and its pathogen, the African swine fever virus (ASFV), threatens the global pig industry. At present, management of ASF epidemic mainly relies on biological prevention and control methods. Moreover, due to the large genome of ASFV, only half of its genes have been characterized in terms of function. Methods: Here, we evaluated a previously uncharacterized viral gene, L60L. To assess the function of this gene, we constructed a deletion strain (SY18ΔL60L) by knocking out the L60L gene of the SY18 strain. To evaluate the growth characteristics and safety of the SY18ΔL60L, experiments were conducted on primary macrophages and pigs, respectively. Results: The results revealed that the growth trend of the recombinant strain was slower than that of the parent strain in vitro. Additionally, 3/5 (60%) pigs intramuscularly immunized with a 105 50% tissue culture infectious dose (TCID50) of SY18ΔL60L survived the 21-day observation period. The surviving pigs were able to protect against the homologous lethal strain SY18 and survive. Importantly, there were no obvious clinical symptoms or viremia. Discussion: These results suggest that L60L could serve as a virulence- and replication-related gene. Moreover, the SY18ΔL60L strain represents a new recombinant live-attenuated ASFV that can be employed in the development of additional candidate vaccine strains and in the elucidation of the mechanisms associated with ASF infection.

Highly Efficient Perovskite/Organic Tandem Solar Cells Enabled by Mixed-Cation Surface Modulation.

Perovskite/organic tandem solar cells (POTSCs) are gaining attention due to their easy fabrication, potential to surpass the S-Q limit, and superior flexibility. However, the low power conversion efficiencies (PCEs) of wide bandgap (Eg) perovskite solar cells (PVSCs) have hindered their development. This work presents a novel and effective mixed-cation passivation strategy (CE) to passivate various types of traps in wide-Eg perovskite. The complementary effect of 4-trifluoro phenethylammonium (CF3 -PEA+ , denoted as CA+ ) and ethylenediammonium (EDA2+ , denoted as EA2+ ) reduces both electron/hole defect densities and non-radiative recombination rate, resulting in a record open-circuit voltage (Voc ) of wide-Eg PVSCs (1.35 V) and a high fill factor (FF) of 83.29%. These improvements lead to a record PCE of 24.47% when applied to fabricated POTSCs, the highest PCE to date. Furthermore, unencapsulated POTSCs exhibit excellent photo and thermal stability, retaining over 90% of their initial PCE after maximum power point (MPP) tracking or exposure to 60 °C for 500 h. These findings imply that the synergic effect of surface passivators is a promising strategy to achieve high-efficiency and stable wide-Eg PVSCs and corresponding POTSCs.

Laparoendoscopic single-site surgery for deep infiltrating endometriosis based on retroperitoneal pelvic spaces anatomy: a retrospective study.

Transumbilical single-port laparoscopy is widely used in gynecological surgery. However, it is rarely used in the treatment of deep infiltrating endometriosis due to its own shortcomings and the complex condition of deep infiltrating endometriosis. The study aims to introduce a transumbilical single-port laparoscopic surgery based on retroperitoneal pelvic spaces anatomy, which can complete the operation of deep infiltrating endometriosis more easily. A retrospective analysis of 63 patients with deep infiltrating endometriosis treated by transumbilical single-port laparoscopy using this method was conducted. The operation duration was 120.00 (85.00 ± 170.00) (35-405) min, the estimated blood loss was 68.41 ± 39.35 ml, the postoperative hospital stay was 5.00 (4.00-6.00) days, and the incidence of postoperative complications was 4.76% (3/63). 1 patient was found to have intestinal injury during operation, 1 patient had ureteral injury after operation, and 1 patient had postoperative pelvic infection, with a recurrence rate of 9.52%. The postoperative scar score was 3.00 (3.00-4.00) and the postoperative satisfaction score was 9.00 (8.00-10.00). In summary, this study demonstrates the feasibility of transumbilical single-port laparoscopic surgery for deep infiltrating endometriosis based on retroperitoneal pelvic spaces anatomy. Hysterectomy, adenomyosis resection, etc. are also feasible with this method, boasting more obvious advantages. This method can make transumbilical single-port laparoscopy more widely used in deep infiltrating endometriosis.

Nonradiative Dynamics Induced by Vacancies in Wide-Gap III-Nitrides: Ab Initio Time-Domain Analysis.

Insightful understanding of defect properties and prevention of defect damage are among the biggest issues in the development of photoelectronic devices based on wide-gap III-nitride semiconductors. Here, we have investigated the vacancy-induced carrier nonradiative dynamics in wide-gap III-nitrides (GaN, AlN, and AlxGa1-xN) by ab initio molecular dynamics and nonadiabatic (NA) quantum dynamics simulations since the considerable defect density in epitaxy samples. E-h recombination is hardly affected by Vcation, which created shallow states near the VBM. Our findings demonstrate that VN in AlN creates defect-assisted nonradiative recombination centers and shortens the recombination time (τ) as in the Shockley-Read-Hall (SRH) model. In GaN, VN improves the NA coupling between the CBM and the VBM. Additionally, increasing x in the AlxGa1-xN alloys accelerates nonradiative recombination, which may be an important issue in further improving the IQE of high Al-content AlxGa1-xN alloys. These findings have significant implications for the improvement of wide-gap III-nitrides-based photoelectronic devices.

Seasonal distribution of microplastics in the surface waters of the Yellow Sea, China.

Different studies are filling the gaps in the distribution map of global marine microplastics. However, the data on the seasonal variation is relatively limited, which may lead to overestimation or underestimation of the distribution level of microplastics. To understand baseline data and seasonal variations of the microplastics in the surface seawater of the Yellow Sea, a survey over four seasons was conducted during 2017-2018. Microplastics were collected using a 330 µm manta net. It was found that the abundance of microplastics was 0.63 ± 0.57 particles/m3. The seasonal abundance variation was spring > summer ≈ winter > autumn. The main categories were foam, line, and fragments, accounting for 32 %, 19 %, and 19 % of the total amount, respectively, and the dominant components were polypropylene, polyethylene, and polyethylene terephthalate, accounting for 38 %, 22 %, and 22 % of particles, respectively. The factors affecting the variation included wind-induced mixing, river input, and environmental topography.

Evaluation of African Swine Fever Virus E111R Gene on Viral Replication and Porcine Virulence.

African swine fever (ASF) is an acute infectious disease of domestic pigs and wild boars caused by the African swine fever virus (ASFV), with up to a 100% case fatality rate. The development of a vaccine for ASFV is hampered by the fact that the function of many genes in the ASFV genome still needs to be discovered. In this study, the previously unreported E111R gene was analyzed and identified as an early-expressed gene that is highly conserved across the different genotypes of ASFV. To further explore the function of the E111R gene, a recombinant strain, SY18ΔE111R, was constructed by deleting the E111R gene of the lethal ASFV SY18 strain. In vitro, the replication kinetics of SY18ΔE111R with deletion of the E111R gene were consistent with those of the parental strain. In vivo, high-dose SY18ΔE111R (105.0 TCID50), administered intramuscularly to pigs, caused the same clinical signs and viremia as the parental strain (102.0 TCID50), with all pigs dying on days 8-11. After being infected with a low dose of SY18ΔE111R (102.0 TCID50) intramuscularly, pigs showed a later onset of disease and 60% mortality, changing from acute to subacute infection. In summary, deletion of the E111R gene has a negligible effect on the lethality of ASFV and does not affect the viruses' ability to replicate, suggesting that E111R could not be the priority target of ASFV live-attenuated vaccine candidates.

Molecular Engineering of Metal-Organic Frameworks as Efficient Electrochemical Catalysts for Water Oxidation.

Metal-organic framework (MOF) solids with their variable functionalities are relevant for energy conversion technologies. However, the development of electroactive and stable MOFs for electrocatalysis still faces challenges. Here, a molecularly engineered MOF system featuring a 2D coordination network based on mercaptan-metal links (e.g., nickel, as for Ni(DMBD)-MOF) is designed. The crystal structure is solved from microcrystals by a continuous-rotation electron diffraction (cRED) technique. Computational results indicate a metallic electronic structure of Ni(DMBD)-MOF due to the Ni-S coordination, highlighting the effective design of the thiol ligand for enhancing electroconductivity. Additionally, both experimental and theoretical studies indicate that (DMBD)-MOF offers advantages in the electrocatalytic oxygen evolution reaction (OER) over non-thiol (e.g., 1,4-benzene dicarboxylic acid) analog (BDC)-MOF, because it poses fewer energy barriers during the rate-limiting *O intermediate formation step. Iron-substituted NiFe(DMBD)-MOF achieves a current density of 100 mA cm-2 at a small overpotential of 280 mV, indicating a new MOF platform for efficient OER catalysis.

Photoaging processes of polyvinyl chloride microplastics enhance the adsorption of tetracycline and facilitate the formation of antibiotic resistance.

Microplastics (MPs), antibiotics and microorganism ubiquitously coexist in aquatic environments. MPs inevitably undergo photoaging processes in aquatic environments, affecting the interactions between MPs and antibiotics and the antibiotic resistance of microorganism. In this study, the impact of photoaging processes of MPs on their adsorption behavior of tetracycline (TC) and related formation of antibiotic resistance were investigated. It was found that the photoaging processes significantly increased the adsorption capacity of TC onto MPs, with the Qe increasing from 0.387 to 0.507 mg/g at 288 K and from 0.507 to 0.688 mg/g at 308 K. The site energy distribution (SED) analysis further confirmed that the enhanced adsorption capacity was attributed to more high-energy adsorption sites acquired from MPs photoaging processes. Moreover, the enhanced adsorption of TC further facilitated the formation of seven antibiotic resistance genes (i.e., tetA, tetB, tetC, tetD, tetE, tetG, tetK) when MPs adsorbed with TC was covered by biofilm. This study helps comprehensively understand the environmental behaviors of co-existing MPs, antibiotics and microorganisms, providing a theoretical basis for evaluating and mitigating their coexistence risks.

Theoretical investigations on P-stabilized boryl cation radicals: from the Aufbau principle to SOMO-HOMO conversion.

We report the characterization of a series of novel phosphinidene-stabilized (P-stabilized) boryl cation radicals, in which the phosphinidene and boryl are stabilised by iPrNHC (iPrNHC[:C{N(iPr)C(H)}2]), and the P-stabilized boryl (P → B) moieties are linked by 1,8-naphthalene (1PB-a), 1,10-biphenyl (1PB-b), 1,2-perylene (1PB-c), and 4,5-perylene (1PB-d), to form a series of 1PB compounds. The 2PB series is designed by adding another P-stabilized boryl (P → B) unit into the 1PB series, in which the two P-stabilized boryl (P → B) moieties for each 2PB compound are linked by 1,4,5,8-naphthalene, (2PB-a), 1,5,6,10-biphenyl (2PB-b), 1,2,7,8-perylene (2PB-c), and 4,5,10,11-perylene (2PB-d), respectively. Theoretical calculations demonstrate that for all the studied molecules, the spin density mainly locates on the B atoms. Interestingly, the series of 2PB(a-d) compounds possess SOMO-HOMO conversion properties, while 1PB(a-d) compounds obey the Aufbau principle, resulting from the difference in the number of the P-stabilized boryl (P → B) moieties and an increase of the π-conjugation bridge that lead to the significantly increased HOMO energy in 2PB(a-d) compounds, which should be responsible for the different structural properties of compounds 1PB(a-d) and 2PB(a-d). The natural bond orbital (NBO) and atoms in molecules (AIM) analysis reveal how the interactions contribute to the covalent bond between P and B atoms. Moreover, the absorption properties show that the spectra of the 2PB(a-d) compounds are red-shifted relative to those of the corresponding 1PB(a-d) compounds in the near infrared region. We hope this work can provide new insights into tuning the electronic structures of the well-defined forms of P-stabilized boryl cation radicals and expand their potential application in organic optoelectronics.

Backbone Engineering Enables Highly Efficient Polymer Hole-Transporting Materials for Inverted Perovskite Solar Cells.

The interface and crystallinity of perovskite films play a decisive role in determining the device performance, which is significantly influenced by the bottom hole-transporting material (HTM) of inverted perovskite solar cells (PVSCs). Herein, a simple design strategy of polymer HTMs is reported, which can modulate the wettability and promote the anchoring by introducing pyridine units into the polyarylamine backbone, so as to realize efficient and stable inverted PVSCs. The HTM properties can be effectively modified by varying the linkage sites of pyridine units, and 3,5-linked PTAA-P1 particularly demonstrates a more regulated molecular configuration for interacting with perovskites, leading to highly crystalline perovskite films with uniform back contact and reduced defect density. Dopant-free PTAA-P1-based inverted PVSCs have realized remarkable efficiencies of 24.89% (certified value: 24.50%) for small-area (0.08 cm2 ) as well as 23.12% for large-area (1 cm2 ) devices. Moreover, the unencapsulated device maintains over 93% of its initial efficiency after 800 h of maximum power point tracking under simulated AM 1.5G illumination.