Unlocking roles of cationic and aromatic residues in peptide amphiphiles in treating drug-resistant gram-positive pathogens.

Multidrug resistance (MDR) is a rising threat to global health because the number of essential antibiotics used for treating MDR infections is increasingly compromised. In this work we report a group of new amphiphilic peptides (AMPs) derived from the well-studied G3 (G(IIKK)3I-NH2) to fight infections from Gram-positive bacteria including susceptible Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA), focusing on membrane interactions. Time-dependent killing experiments revealed that substitutions of II by WW (GWK), II by FF (GFK) and KK by RR (GIR) resulted in improved bactericidal efficiencies compared to G3 (GIK) on both S. aureus and MRSA, with the order of GWK > GIR > GFK > GIK. Electronic microscopy imaging revealed structural disruptions of AMP binding to bacterial cell walls. Fluorescence assays including AMP binding to anionic lipoteichoic acids (LTA) in cell-free and cell systems indicated concentration and time-dependent membrane destabilization associated with bacterial killing. Furthermore, AMP's binding to anionic plasma membrane via similar fluorescence assays revealed a different extent of membrane depolarization and leakage. These observations were supported by the penetration of AMPs into the LTA barrier and the subsequent structural compromise to the cytoplasmic membrane as revealed from SANS (small angle neutron scattering). Both experiments and molecular dynamics (MD) simulations revealed that GWK and GIR could make the membrane more rigid but less effective in diffusive efficiency than GIK and GFK through forming intramembrane peptide nanoaggregates associated with hydrophobic mismatch and formation of fluidic and rigid patches. The reported peptide-aggregate-induced phase-separation emerged as a crucial factor in accelerated membrane disintegration and fast bacterial killing. This work has demonstrated the importance of membrane interactions to the development of more effective AMPs and the relevance of the approaches as reported in assisting this area of research.

Elevating Charge Transport Layer for Stable Perovskite Light-Emitting Diodes.

Ion migration is a major factor affecting the long term stability of perovskite light-emitting diodes (LEDs), which limits their commercialization potential. The accumulation of excess halide ions at the grain boundaries of perovskite films is a primary cause of ion migration in these devices. Here, it is demonstrated that the channels of ion migrations can be effectively impeded by elevating the hole transport layer between the perovskite grain boundaries, resulting in highly stable perovskite LEDs. The unique structure is achieved by reducing the wettability of the perovskites, which prevents infiltration of the upper hole-transporting layer into the spaces of perovskite grain boundaries. Consequently, nanosized gaps are formed between the excess halide ions and the hole transport layer, effectively suppressing ion migration. With this structure, perovskite LEDs with operational half-lifetimes of 256 and 1774 h under current densities of 100 and 20 mA cm-2 respectively are achieved. These lifetimes surpass those of organic LEDs at high brightness. It is further found that this approach can be extended to various perovskite LEDs, showing great promise for promoting perovskite LEDs toward commercial applications.

Interface Dipole Management of D-A-Type Molecules for Efficient Perovskite Solar Cells.

Interfacial engineering of perovskite films has been the main strategies in improving the efficiency and stability of perovskite solar cells (PSCs). In this study, three new donor-acceptor (D-A)-type interfacial dipole (DAID) molecules with hole-transporting and different anchoring units are designed and employed in PSCs. The formation of interface dipoles by the DAID molecules on the perovskite film can efficiently modulate the energy level alignment, improve charge extraction, and reduce non-radiative recombination. Among the three DAID molecules, TPA-BAM with amide group exhibits the best chemical and optoelectrical properties, achieving a champion PCE of 25.29% with the enhanced open-circuit voltage of 1.174 V and fill factor of 84.34%, due to the reduced defect density and improved interfacial hole extraction. Meanwhile, the operational stability of the unencapsulated device has been significantly improved. Our study provides a prospect for rationalized screening of interfacial dipole materials for efficient and stable PSCs.

3D Poly (L-lactic acid) fibrous sponge with interconnected porous structure for bone tissue scaffold.

Large bone defects, often resulting from trauma and disease, present significant clinical challenges. Electrospun fibrous scaffolds closely resembling the morphology and structure of natural ECM are highly interested in bone tissue engineering. However, the traditional electrospun fibrous scaffold has some limitations, including lacking interconnected macropores and behaving as a 2D scaffold. To address these challenges, a sponge-like electrospun poly(L-lactic acid) (PLLA)/polycaprolactone (PCL) fibrous scaffold has been developed by an innovative and convenient method (i.e., electrospinning, homogenization, progen leaching and shaping). The resulting scaffold exhibited a highly porous structure (overall porosity = 85.9 %) with interconnected, regular macropores, mimicking the natural extracellular matrix. Moreover, the incorporation of bioactive glass (BG) particles improved the hydrophilicity (water contact angle = 79.7°) and biocompatibility and promoted osteoblast cell growth. In-vitro 10-day experiment revealed that the scaffolds led to high cell viability. The increment of the proliferation rates was 195.4 % at day 7 and 281.6 % at day 10. More importantly, Saos-2 cells could grow, proliferate, and infiltrate into the scaffold. Therefore, this 3D PLLA/PCL with BG sponge holds great promise for bone defect repair in tissue engineering applications.

Self-Polymerized Spiro-Type Interfacial Molecule toward Efficient and Stable Perovskite Solar Cells.

In the pursuit of highly efficient perovskite solar cells, spiro-OMeTAD has demonstrated recorded power conversion efficiencies (PCEs), however, the stability issue remains one of the bottlenecks constraining its commercial development. In this study, we successfully synthesize a novel self-polymerized spiro-type interfacial molecule, termed v-spiro. The linearly arranged molecule exhibits stronger intermolecular interactions and higher intrinsic hole mobility compared to spiro-OMeTAD. Importantly, the vinyl groups in v-spiro enable in situ polymerization, forming a polymeric protective layer on the perovskite film surface, which proves highly effective in suppressing moisture degradation and ion migration. Utilizing these advantages, poly-v-spiro-based device achieves an outstanding efficiency of 24.54 %, with an enhanced open-circuit voltage of 1.173 V and a fill factor of 81.11 %, owing to the reduced defect density, energy level alignment and efficient interfacial hole extraction. Furthermore, the operational stability of unencapsulated devices is significantly enhanced, maintaining initial efficiencies above 90 % even after 2000 hours under approximately 60 % humidity or 1250 hours under continuous AM 1.5G sunlight exposure. This work presents a comprehensive approach to achieving both high efficiency and long-term stability in PSCs through innovative interfacial design.

The Biological Function of POLA2 in Hepatocellular Carcinoma.

INTRODUCTION: The role and prognostic value of POLA2 in liver cancer were comprehensively analyzed through TCGA, GEO, and ICGC databases, and the role of POLA2 in liver cancer cells and the regulatory mechanism involved were further verified through cell experiments. Hepatocellular carcinoma (HCC) is the most prevalent malignancy with high morbidity and mortality. Consequently, it is critical to identify robust and reliable predictive biomarkers and therapeutic targets for HCC patients. POLA2 is involved in the regulation of various tumors, but the specific role of POLA2 in HCC has not been reported. The regulatory role and prognostic value of POLA2 in HCC were determined by bioinformatics techniques and cell experiments. METHOD: The specific role and prognostic value of POLA2 in HCC were comprehensively analyzed by combining the expression data of POLA2 in TCGA, GEO, and ICGC databases and clinical data. In clinical samples, the expression of POLA2 in liver cancer was verified by QPCR. Further, the regulatory role of POLA2 in HCC was explored through cell experiments such as CCK-8, clonal formation experiment, EDU cell proliferation experiment, and flow cytometry. In terms of mechanism exploration, western blot was used to verify the specific regulatory mechanism that POLA2 participated in. Finally, the relationship between POLA2 and immune invasion of HCC was analyzed by using the TIMER database. RESULT: A POLA2 expression and prognosis analysis of HCC patients was conducted using the TCGA, GEO, and ICGC databases. We hypothesized that POLA2 might be one of the key factors contributing to the HCC progression. According to a combined analysis of TCGA, ICGC, and GEO databases, POLA2 was highly expressed in HCC. This was further confirmed in clinical samples using the qPCR. POLA2 knockdown was also performed in vitro on HCC cell lines to study the changes in their biological behavior. We confirmed that POLA2 was associated with HCC proliferation by CCK-8, Colony Formation, and EDU assay. We verified the POLA2's involvement in cell cycle regulation using flow techniques. The relationship between POLA2 and PI3K/AKT/mTOR pathway was explored using Western Blotting experiments regarding its mechanism. Further analysis revealed that the POLA2 expression was significantly associated with HCC immune infiltration. CONCLUSION: Our study demonstrated POLA2's importance in HCC development and progression and its potential role as a biomarker for disease progression on multiple levels. POLA2 has an important role in regulating the cell cycle and cell proliferation. By interfering with the cell cycle and proliferation, HCC cell growth is inhibited. Furthermore, POLA2 expression was significantly associated with immune infiltration. POLA2 may play a role in HCC immunotherapy based on its correlation with several immune cell types' genetic markers. The findings of this study are expected to lead to new anticancer strategies for HCC.

Spherulitic Crystallization of CsCu2I3 for High Performance Ultraviolet Photodetectors.

Ternary copper halides have become promising materials for UV photodetection due to their stability and eco-friendliness. However, the uncontrollable crystallization induces high-concentration defects in these films, inherently limiting further improvement in device performance. Herein, we reveal the antisolvent-assisted crystallization kinetics mechanism of CsCu2I3 during the film-forming process. The nucleation rate is manipulated by adjusting precursor supersaturation using different antisolvents, resulting in decreased density and preferential orientation of the nuclei within the wet film. Subsequent annealing leads to a homogeneous and low-defect CsCu2I3 film with 40-µm-scale spherulites. A resulting visible-blind ultraviolet photodetector exhibits a responsivity of 8.73 A W-1, a specific detectivity of 5.28 × 1012 jones, and a response speed of 1.12 ms. The unencapsulated photodetector shows negligible degradation of responsivity in ambient air (∼70% humidity) for one month. Moreover, the flexible device with a responsivity of 420.2 mA W-1 and a detectivity of 1.18 × 1012 jones also shows excellent bending stability.

Monolithically-grained perovskite solar cell with Mortise-Tenon structure for charge extraction balance.

Although the power conversion efficiency values of perovskite solar cells continue to be refreshed, it is still far from the theoretical Shockley-Queisser limit. Two major issues need to be addressed, including disorder crystallization of perovskite and unbalanced interface charge extraction, which limit further improvements in device efficiency. Herein, we develop a thermally polymerized additive as the polymer template in the perovskite film, which can form monolithic perovskite grain and a unique "Mortise-Tenon" structure after spin-coating hole-transport layer. Importantly, the suppressed non-radiative recombination and balanced interface charge extraction benefit from high-quality perovskite crystals and Mortise-Tenon structure, resulting in enhanced open-circuit voltage and fill-factor of the device. The PSCs achieve certified efficiency of 24.55% and maintain >95% initial efficiency over 1100 h in accordance with the ISOS-L-2 protocol, as well as excellent endurance according to the ISOS-D-3 accelerated aging test.

A Biodegradable Stereo-Complexed Poly (Lactic Acid) Drinking Straw of High Heat Resistance and Performance.

Current biodegradable drinking straws suffer from poor heat resistance and rigidity when wet, causing user dissatisfaction. Here, a fully biodegradable straw formed by stereocomplexation of poly (lactic acid) (SC-PLA) is reported. Because of the unique strong interaction and high density of link chains between stereocomplex crystallites (over 70% crystallinity), SC-PLA straws outperform their counterparts on the market. This coupled with the advantages of simple processing (solution casting and annealing) and relatively low cost (~2.06 cents per straw) makes SC-PLA drinking straws a superior substitute for plastic ones. Commercially available PLLA straws lose almost 60% of their flexural strength when wet compared to less than 5% of the SC-PLA straws proposed in this study.

Orientated crystallization of FA-based perovskite via hydrogen-bonded polymer network for efficient and stable solar cells.

Incorporating mixed ion is a frequently used strategy to stabilize black-phase formamidinum lead iodide perovskite for high-efficiency solar cells. However, these devices commonly suffer from photoinduced phase segregation and humidity instability. Herein, we find that the underlying reason is that the mixed halide perovskites generally fail to grow into homogenous and high-crystalline film, due to the multiple pathways of crystal nucleation originating from various intermediate phases in the film-forming process. Therefore, we design a multifunctional fluorinated additive, which restrains the complicated intermediate phases and promotes orientated crystallization of α-phase of perovskite. Furthermore, the additives in-situ polymerize during the perovskite film formation and form a hydrogen-bonded network to stabilize α-phase. Remarkably, the polymerized additives endow a strongly hydrophobic effect to the bare perovskite film against liquid water for 5 min. The unencapsulated devices achieve 24.10% efficiency and maintain >95% of the initial efficiency for 1000 h under continuous sunlight soaking and for 2000 h at air ambient of ~50% humid, respectively.

HMGCL-induced ß-hydroxybutyrate production attenuates hepatocellular carcinoma via DPP4-mediated ferroptosis susceptibility.

BACKGROUND: Metabolic disorder is an essential characteristic of tumor development. Ketogenesis is a heterogeneous factor in multiple cancers, but the effect of ketogenesis on hepatocellular carcinoma (HCC) is elusive. METHODS: We aimed to explain the role of ketogenesis-related hydroxy-methyl-glutaryl-CoA lyase (HMGCL) on HCC suppression. Expression pattern of HMGCL in HCC specimens was evaluated by immunohistochemistry (IHC). HMGCL was depleted or overexpressed in HCC cells to investigate the functions of HMGCL in vitro and in vivo. The anti-tumor function of HMGCL was studied in subcutaneous xenograft and Trp53Δhep/Δhep; c-Myc-driven HCC mouse models. The mechanism of HMGCL-mediated tumor suppression was studied by IHC, western blot (WB) and Cut & Tag. RESULTS: HMGCL depletion promoted HCC proliferation and metastasis, whereas its overexpression reversed this trend. As HMGCL catalyzes ß-hydroxy-butyric acid (ß-OHB) production, we discovered that HMGCL increased acetylation at histone H3K9, which further promoted the transcription of dipeptidyl peptidase 4 (DPP4), a key protein maintains intracellular lipid peroxidation and iron accumulation, leading to HCC cells vulnerability to erastin- and sorafenib-induced ferroptosis. CONCLUSION: Our study identified a critical role of HMGCL on HCC suppression, of which HMGCL regulated H3K9 acetylation through ß-OHB and modulating the expression of DPP4 in a dose-dependent manner, which led to ferroptosis in HCC cells.

ASF1B, as an Independent Prognostic Biomarker, Correlates with Immune Infiltrates in Hepatocellular Carcinoma.

BACKGROUND: Hepatocellular Carcinoma (HCC) is one of the fastest-growing malignancies globally. The impact of surgical treatment is limited, and molecular targeted therapy has not yielded a consistent efficacy. This warrants for identification of novel molecular targets. The Anti- Silencing Function of 1B histone chaperone (ASF1B) was previously studied in numerous cancers. However, the understanding of its role in HCC is limited. METHODS: The TIMER database was used to analyze the ASF1B expression in pan-cancer and paracarcinoma tissues. ASF1B expression in HCC was confirmed using the HCCDB database, Quantitative real-time PCR (q-PCR), and Western Blot (WB) assays. The relationship between clinicopathological parameters and ASF1B expression was analyzed using UALCAN, whereas the prognostic value of ASF1B was evaluated using the GEPIA database. Linkedomics and cBioPortal databases were used to validate the ASF1B co-expression associated with immune infiltration by the TIMER database. Moreover, cell proliferation after ASF1B-knockdown was determined through CCK8 and clone formation assays. RESULTS: ASF1B was highly expressed in HCC tissues, and the expression levels were linked to tumor grade, race, and disease stage. Univariate and multivariate Cox models showed that ASF1B is an independent prognostic factor in HCC. CCK8 and clone formation assays demonstrated that ASF1B promotes cell proliferation. Gene co-expression analysis in Linkedomics demonstrated that HJURP, KIF2C, KIF4A, KIF18B, and KIFC1 expressions were closely associated with ASF1B and immune infiltrate cells. CONCLUSION: This study shows that ASF1B promotes the proliferation of HCC. Besides, ASF1B could be a potential prognostic biomarker for HCC patients.

Orientation Regulation of One-Dimensional CsCu2I3 Perovskites for Visible-Blind Ultraviolet Photodetectors.

Ternary copper halides with a formula of CsCu2X3 (X = Cl, Br, I) have been considered as prospective materials for ultraviolet (UV) photodetectors, due to their suitable band gaps, environmental stability, eco-friendliness, and low cost. However, the crystal orientation of one-dimensional (1D) CsCu2X3 perovskites significantly affects the exciton/carrier transport in the films and thus the photodetector performance. Here, we tune the crystal orientation and exciton/charge transport of 1D CsCu2I3 perovskite films by using antisolvents during the film formation process. Compared to the randomly oriented film treated by ethyl acetate, the CsCu2I3 film using toluene as antisolvent exhibits preferential (221)-oriented growth, which induces enhanced vertical exciton diffusion/charge transport and suppressed nonradiative recombination. On the basis of this strategy, we demonstrate a self-powered, stable, and visible-blind UV photodetector with significantly enhanced response speed and detectivity. Our work clarifies that tuning the crystal orientation of 1D CsCu2X3 perovskites is the key to achieve efficient exciton diffusion/charge transport and thus high-performance lead-free perovskite optoelectronic devices.

All roads lead to Rome - a review of the potential mechanisms by which exerkines exhibit neuroprotective effects in Alzheimer's disease.

Age-related neurodegenerative disorders such as Alzheimer's disease (AD) have become a critical public health issue due to the significantly extended human lifespan, leading to considerable economic and social burdens. Traditional therapies for AD such as medicine and surgery remain ineffective, impractical, and expensive. Many studies have shown that a variety of bioactive substances released by physical exercise (called "exerkines") help to maintain and improve the normal functions of the brain in terms of cognition, emotion, and psychomotor coordination. Increasing evidence suggests that exerkines may exert beneficial effects in AD as well. This review summarizes the neuroprotective effects of exerkines in AD, focusing on the underlying molecular mechanism and the dynamic expression of exerkines after physical exercise. The findings described in this review will help direct research into novel targets for the treatment of AD and develop customized exercise therapy for individuals of different ages, genders, and health conditions.

Cell division cycle associated 8: A novel diagnostic and prognostic biomarker for hepatocellular carcinoma.

The cell division cycle associated 8 (CDCA8) is a crucial component of the chromosome passenger complex (CPC). It has been implicated in the regulation of cell dynamic localization during mitosis. However, its role in hepatocellular carcinoma (HCC) is not clearly known. In this study, data of 374 patients with HCC were retrieved from the Cancer Genome Atlas (TCGA) database. Pan analysis of Gene Expression Profiling Interactive Analysis (GEPIA) database was performed to profile the mRNA expression of CDCA8 in HCC. Then, the Kaplan-Meier plotter database was analysed to determine the prognostic value of CDCA8 in HCC. In addition, samples of tumour and adjacent normal tissues were collected from 88 HCC patients to perform immunohistochemistry (IHC), reverse transcription-quantitative polymerase chain reaction (qRT-PCR) and Western blotting. The results obtained from bioinformatic analyses were validated through CCK-8 assay, EdU assay, colony formation assay, cell cycle assays and Western blotting experiments. Analysis of the Kaplan-Meier plotter database showed that high expression of CDCA8 may lead to poor overall survival (OS, p = 4.06e-05) in patients with HCC. For the 88 patients with HCC, we found that stages and grades appeared to be strongly linked with CDCA8 expression. Furthermore, the high expression of CDCA8 was found to be correlated with poor OS (p = 0.0054) and progression-free survival (PFS, p = 0.0009). In vitro experiments revealed that inhibition of CDCA8 slowed cell proliferation and blocked the cell cycle at the G0/G1 phase. In vivo experiments demonstrated that inhibition of CDCA8 inhibited tumour growth. Finally, blockade of CDCA8 reduced the expression levels of cyclin A2, cyclin D1, CDK4, CDK6, Ki67 and PCNA. And, there is an interaction between CDCA8 and E2F1. In conclusion, this research demonstrates that CDCA8 may serve as a biomarker for early diagnosis and prognosis prediction of HCC patients. In addition, CDCA8 could be an effective therapeutic target in HCC.

ASRGL1 Correlates With Immune Cell Infiltration in Hepatocellular Carcinoma and Can Serve as a Prognostic Biomarker.

BACKGROUND: The enzyme L-asparaginase (ASRGL1) catalyzes the hydrolysis of L-asparagine (Asn) to L-aspartic acid (Asp) and ammonia. Numerous studies have shown a strong correlation between ASRGL1 expression and tumorigenesis. However, the expression and biological function of ASRGL1 in hepatocellular carcinoma (HCC) are still unclear. METHODS: We explored the mRNA expression of ASRGL1 in HCC using the HCCDB, Oncomine, and TIMER 2.0 databases. Western blotting and immunohistochemical analyses were also used to determine the mRNA expression of ASRGL1 in HCC. LinkedOmics was used to analyze the genes co-expressed with ASRGL1 and regulators including kinases, miRNAs, and transcription factors. The Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of the co-expressed genes were also investigated using LinkedOmics. The correlation between ASRGL1 expression and immune infiltrates was analyzed using the TIMER 2.0 and Gene Expression Profiling Interactive Analysis (GEPIA) databases. The effects of ASRGL1 expression on patient outcome were investigated using the UALCAN and GEPIA databases, and the Kaplan-Meier plotter. c-Bioportal was used to explore the mutations of ASRGL1 in HCC. RESULTS: Compared with the adjacent tissues, ASRGL1 was upregulated in HCC. High ASRGL1 expression in HCC indicated poor relapse-free survival, progression-free survival, disease-specific survival, and overall survival. The expression of ASRGL1 was significantly correlated with infiltrating levels of B cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells in HCC. CONCLUSION: Our findings suggest that ASRGL1 is overexpressed in HCC and that ASRGL1 expression was significantly correlated with immune infiltration in HCC and prognosis. Therefore, ASRGL1 may serve as a biomarker for the early diagnosis and treatment of HCC.

Immune Score Indicator for the Survival of Melanoma Patients Based on Tumor Microenvironment.

BACKGROUND: Tumor microenvironment (TME) refers to the cellular environment where tumors exist, including immune cells, fibroblasts, stromal cells, chemokines, etc. TME is closely related to the prognosis of various tumors; nevertheless, limited studies have established predictive prognosis models based on TME. This work aims to construct a survival prediction model for melanoma patients based on TME. METHODS: Data of 482 melanoma patients were extracted from The Cancer Genome Atlas (TCGA) database. Based on the infiltration of immune cells (Immune score), stromal cells (Stromal score), and tumor purity (Estimate score), the "Estimate" algorithm was used to construct 3 scores for each patient. To identify the differentially expressed genes (DEGs), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted using DAVID database and visualized using the R software. The STRING database was used to construct the protein-protein interaction (PPI) network and functional modules. FGD2 expression was confirmed via Western Blotting and quantitative reverse transcription PCR (RT-qPCR) analyses. RESULTS: Patients with higher immune scores estimate scores showed better OS than those with lower scores. All three scores were related to age and primary tumor stage. Further, DEGs between patients with high immune/stromal scores and low immune/stromal scores were screened. Eventually, 10 down-regulated DEGs and 201 up-regulated DEGs were identified as TME associated genes. Out of these, the FGD2 gene demonstrated close association with survival and was confirmed in the included melanoma patients. CONCLUSION: In summary, TME is closely associated with the prognosis of melanoma patients. Besides, genes including FGD2 promote the TME-mediated regulation of melanoma.

Intermediate-phase-assisted low-temperature formation of γ-CsPbI3 films for high-efficiency deep-red light-emitting devices.

Black phase CsPbI3 is attractive for optoelectronic devices, while usually it has a high formation energy and requires an annealing temperature of above 300 °C. The formation energy can be significantly reduced by adding HI in the precursor. However, the resulting films are not suitable for light-emitting applications due to the high trap densities and low photoluminescence quantum efficiencies, and the low temperature formation mechanism is not well understood yet. Here, we demonstrate a general approach for deposition of γ-CsPbI3 films at 100 °C with high photoluminescence quantum efficiencies by adding organic ammonium cations, and the resulting light-emitting diode exhibits an external quantum efficiency of 10.4% with suppressed efficiency roll-off. We reveal that the low-temperature crystallization process is due to the formation of low-dimensional intermediate states, and followed by interionic exchange. This work provides perspectives to tune phase transition pathway at low temperature for CsPbI3 device applications.

Microcavity top-emission perovskite light-emitting diodes.

Light-emitting diodes (LEDs) based on perovskites show great potential in lighting and display applications. However, although perovskite films with high photoluminescence quantum efficiencies are commonly achieved, the efficiencies of perovskite LEDs are largely limited by the low light out-coupling efficiency. Here, we show that high-efficiency perovskite LEDs with a high external quantum efficiency of 20.2% and an ultrahigh radiant exitance up to 114.9 mW cm-2 can be achieved by employing the microcavity effect to enhance light extraction. The enhanced microcavity effect and light out-coupling efficiency are confirmed by the study of angle-dependent emission profiles. Our results show that both the optical and electrical properties of the device need to be optimized to achieve high-performance perovskite LEDs.