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Osimertinib (Osi) is a widely used epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). However, the emergence of resistance is inevitable, partly due to the gradual evolution of adaptive resistant cells during initial treatment. Here, we find that Osi treatment rapidly triggers adaptive resistance in tumor cells. Metabolomics analysis reveals a significant enhancement of oxidative phosphorylation (OXPHOS) in Osi adaptive-resistant cells. Mechanically, Osi treatment induces an elevation of NCOA4, a key protein of ferritinophagy, which maintains the synthesis of iron-sulfur cluster (ISC) proteins of electron transport chain and OXPHOS. Additionally, active ISC protein synthesis in adaptive-resistant cells significantly increases the sensitivity to copper ions. Combining Osi with elesclomol, a copper ion ionophore, significantly increases the efficacy of Osi, with no additional toxicity. Altogether, this study reveals the mechanisms of NCOA4-mediated ferritinophagy in Osi adaptive resistance and introduces a promising new therapy of combining copper ionophores to improve its initial efficacy.
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Carcinoma de Pulmón de Células no Pequeñas , Resistencia a Antineoplásicos , Receptores ErbB , Ferritinas , Neoplasias Pulmonares , Animales , Humanos , Ratones , Acrilamidas/farmacología , Compuestos de Anilina/farmacología , Autofagia/efectos de los fármacos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Tumoral , Cobre/metabolismo , Receptores ErbB/antagonistas & inhibidores , Ferritinas/metabolismo , Indoles/farmacología , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Ratones Desnudos , Coactivadores de Receptor Nuclear/metabolismo , Coactivadores de Receptor Nuclear/genética , Fosforilación Oxidativa/efectos de los fármacos , Pirimidinas/farmacología , /farmacologíaRESUMEN
BACKGROUND: Colorectal cancer (CRC) is a common malignancy with high morbidity and mortality. To improve CMC prognosis, research must identify safe and effective natural drugs that improve the proliferation, migration, and epithelial mesenchymal transition (EMT) processes of CRC. The purpose of this paper is to understand how cichoric acid (CA) impacts CRC proliferation, metastasis, and EMT of CRC by adjusting the Ras homolog family member A (RhoA)/RHO-associated coiled coil protein kinase (ROCK) pathway. METHODS: Human Colon Cancer Cells (HCT116) cells were randomly divided into Control (blank medium treatment), low concentration CA (CA-L), medium concentration CA (CA-M), high concentration CA (CA-H), and high-concentration CA+RhoA activator U46619 (CA-H+U46619) groups. Cell proliferation, migration and invasion, and apoptosis were evaluated with cell counting kit-8 (CCK-8) assay, transwell assay, and flow cytometry, respectively. The expression of RhoA, ROCK, and EMT-associated proteins were detected by Western Blot. The CRC transplanted tumor model of nude mice was constructed, and the mice were grouped into low-dose CA (CA-Low, 15 mg/kg CA), high-dose CA (CA-High, 30 mg/kg CA), high-dose CA+RhoA activator U46619 (CA-High+U46619, 30 mg/kg CA+10 mM U46619), and Model groups at random, with 12 mice in each group. Tumor volume, mass, and inhibition rate were measured and calculated, and the pathological changes of tumor in nude mice were detected by hematoxylin-eosin (HE) staining. RESULTS: Compared with Control, the optical density of cells at 450 nm (OD450) value (48 h, 72 h), cell migration number, cell invasion number, RhoA, ROCK1, N-cadherin, vimentin protein expression levels of HCT116 cells were reduced in CA-M and CA-H groups; however, E-cadherin level and apoptosis rate were increased (p < 0.05). In the CA-High group, we observed a significant decrease (p < 0.05) in both tumor volume and mass in nude mice. Additionally, the tumor tissue cells exhibited better organization, reduced size, reduced tumor and vascular tissue hyperplasia, and decreased infiltration of inflammatory cells. U46619 decreased the retardation of CA on the proliferation, EMT, and migration of CRC tumor cells as well as the growth of transplanted CRC tumors in nude mice. CONCLUSIONS: CA may reduce CRC migration, proliferation, and EMT by inhibiting the activation of the RhoA/ROCK signaling pathway.
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Ácidos Cafeicos , Neoplasias Colorrectales , Succinatos , Proteína de Unión al GTP rhoA , Humanos , Animales , Ratones , Ratones Desnudos , Línea Celular Tumoral , Proteína de Unión al GTP rhoA/metabolismo , Proteína de Unión al GTP rhoA/farmacología , Proteína de Unión al GTP rhoA/uso terapéutico , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/metabolismo , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacología , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/uso terapéutico , Transducción de Señal , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/patología , Transición Epitelial-Mesenquimal , Proliferación Celular , Movimiento Celular , Quinasas Asociadas a rho/metabolismoRESUMEN
An inverted AluYb8 insertion in the MUTYH intron 15 (AluYb8MUTYH variant) has been reported to be associated with reduced MUTYH1 expression and mitochondrial dysfunction with age. However, the underlying mechanism remains unknown. In this study, we identified a novel transcript associated with the AluYb8MUTYH variant, which revealed that this transcript is about 780 nucleotides in length with a poly-A tail, lacks protein-coding potential, referred to as lncMUTYH. The results from the reporter gene system confirmed that the lncMUTYH down-regulates MUTYH1 expression at the translational level. Site-directed mutagenesis on the 5'-terminal exon sequences of α-MUTYH and lncMUTYH constructs revealed that lncMUTYH can act as a trans-regulator that depends on the partial base pairing between its exonized AluYb8 sequence and the 5'UTR of α-MUTYH to impede MUTYH 1 expression. Furthermore, we have demonstrated a correlation between decreased mitochondrion-localized MUTYH1 caused by lncMUTYH and lowered levels of mitochondrial biological function indicators, such as mtDNA content, mitochondrial regulatory gene expression, oxygen consumption rate, ATP product, and mitochondrial respiratory capacity. Notably, we found that lncMUTYH inhibited the M2-like polarization of macrophages, and CD68/CD206-positive cell fractions were significantly lower in lncMUTYH ectopically expressing cells. The results confirmed that the AluYb8MUTYH-associated lncMUTYH, derived from an AluYb8 insertion mutation, acts as a trans-regulatory factor that inhibits the MUTYH1 protein expression, leading to a progressive mitochondrial dysfunction that may disrupt macrophage differentiation. In summary, lncMUTYH can contribute to AluYb8MUTYH-associated mitochondrial dysfunction with age and hamper the macrophage polarization process, potentially increasing the risk of developing age-related diseases.
A novel non-coding RNA was identified derived from the AluYb8 insertion in the MUTYH gene, namely lncMUTYH.LncMUTYH selectively decreased the MUTYH1 protein localized in mitochondrial, which is dependent on the sequence and orientation derived from AluYb8 insertion.Overexpression of lncMUTYH dampens the mitochondrial function and M2-like polarization of macrophages, partly due to the suppression of the MUTYH1 protein.
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Macrófagos , Enfermedades Mitocondriales , Humanos , Macrófagos/metabolismo , Mitocondrias , ARN no Traducido/metabolismoRESUMEN
BACKGROUND: It has been reported that smoking history as a predictor of immunotherapy efficacy in patients with advanced lung cancer, however, the underlying mechanisms of this phenomenon remain largely unknown. METHODS: The patients with lung adenocarcinoma's (LUAD) cohort and the orthotopical transplanted mouse model were used to explore the correlation between smoking status and tertiary lymphoid structure (TLS) and chemokine CCL21, respectively. Cell adhesion and co-immunoprecipitation assays were performed to explore the interaction between CD4+T cells and CD20+B cells under tobacco exposure. Chromatin immunoprecipitation-PCR was used to dissect the mechanism of upregulated CCL21 secretion in tobacco treatment. Serum CCL21 level was recorded in patients with LUAD treated with immunotherapy. RESULTS: Here we observed that individuals with a smoking history exhibit an increased quantity and maturation level of TLS compared with non-smokers, along with higher levels of CCL21 secretion. Tobacco exposure promoted CCL21 expression in an epithelial cell-intrinsic manner, of which BaP, the main component of tobacco, facilitated the nuclear retention of the aryl hydrocarbon receptor that occupied the promoter of CCL21. Additionally, the activated CCL21/CCR7 axis increased the CD11a expression of CD4+T cells, boosting the interaction with CD20+B cells dependent on ICAM1, which potentially induced the TLSs formation. Patients with elevated serum levels of CCL21 benefited more from immunotherapy. CONCLUSIONS: Patients with a smoking history exhibited higher levels of TLS via the CCL21-dependent mechanism, serum CCL21 was identified as a reliable biomarker for predicting the efficacy of immunotherapy.
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Quimiocina CCL21 , Estructuras Linfoides Terciarias , Animales , Ratones , Línea Celular Tumoral , Quimiocina CCL21/metabolismo , Inmunoterapia , HumanosRESUMEN
Lung adenocarcinoma (LUAD) exhibits high heterogeneity and is well known for its high genetic variation. Recently, the understanding of non-genetic variation provides a new perspective to study the heterogeneity of LUAD. Little is known about whether super-enhancers (SEs) may be primarily responsible for the inter-tumor heterogeneity of LUAD. We used super-enhancer RNA (seRNA) levels of a large-scale clinical well-annotated LUAD cohort to stratify patients into three clusters with different prognosis and other malignant characteristics. Mechanistically, estrogen-related receptor alpha (ERRα) in cluster 3-like cell lines acts as a cofactor of BRD4 to assist SE-promoter loops to activate glycolysis-related target gene expression, thereby promoting glycolysis and malignant progression, which confers a therapeutic vulnerability to glycolytic inhibitors. Our study identified three groups of patients according to seRNA levels, among which patients in cluster 3 have the worst prognosis and vulnerability of glycolysis dependency. We also proposed a 3-TF index model to stratify patients with glycolysis-addicted tumors according to tumor SE stratification.
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BACKGROUND: Immune checkpoint inhibitors (ICIs) are standard therapies for patients with advanced lung adenocarcinoma and significantly improve treatment outcomes. The effect of tobacco smoking on the response of immune checkpoint inhibitors is somewhat diverging. Here, we assessed the impact of tobacco exposure on the tumor microenvironment and developed a feasible tool for predicting prognosis. METHODS: Whole exon sequence data and the corresponding clinical information were downloaded from the Cancer Genome Atlas. The signature was developed by the Random Forest algorithm. CIBERSORTx online tool was used to estimate immune infiltration. Functional assays were performed to assess the roles of tobacco exposure in cancer cells. Immunohistochemistry (IHC) was performed to identify and validate the immune activation status. RESULTS: The TMB of lifelong non-smoker, current reformed smoker for over 15 years, current reformed smoker<15 years and current smoker had a significantly increasing trend in LUAD patients. In vitro tobacco exposure promoted the expression of PD-L1 and malignant phenotype of LUAD cells. In addition, patients with high Random Forest score (RFscore) had a poorer prognosis than those with low RFscore. The ROC curve analysis of RFscore revealed a promising prognostic capability. Memory activated CD4 + T cells, CD8 + t cells and memory B cells were noticeably enriched in the high RFscore group and PDCD1 appreciably upregulated in the high RFscore group as well. Furthermore, IHC results suggested that patients with high RFscore remained an immune activation status, indicating a positive correlation between RFscore and patient's immune status. CONCLUSION: Our analysis provides further insight into the profound impacts of tobacco exposure on tumor immune microenvironment and envisions integrative predictive models of RFscore, predicting the prognosis of smoking lung adenocarcinoma, which might help to understand the potential mechanism of smoking exposure on tumor immune microenvironment.
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Adenocarcinoma/inmunología , Subgrupos de Linfocitos B/inmunología , Neoplasias Pulmonares/inmunología , Linfocitos T/inmunología , Fumar Tabaco/efectos adversos , Células A549 , Adenocarcinoma/diagnóstico , Adenocarcinoma/mortalidad , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Biomarcadores de Tumor/metabolismo , Biología Computacional , Conjuntos de Datos como Asunto , Regulación Neoplásica de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Memoria Inmunológica , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/mortalidad , Modelos Estadísticos , Pronóstico , Proteómica , Análisis de Supervivencia , Microambiente TumoralRESUMEN
BACKGROUND: This study aimed to develop a reliable immune signature based on B-cell proportion to predict the prognosis and benefit of immunotherapy in LUAD. METHODS: The proportion of immune cells in the TCGA-LUAD dataset was estimated using MCP-counter. The Least Absolute Shrinkage and Selector Operation was used to identify a prognostic signature and validated in an independent cohort. We used quantitative reverse transcription-polymerase chain reaction (qRT-PCR) data and formalin-fixed paraffin-embedded (FFPE) specimens immunohistochemistry to illustrate the correlation between prognostic signature and leukocyte migration. RESULTS: We found that the relative abundance of B lineage positively correlated with overall survival. Then, we identified a 13-gene risk-score prognostic signature based on B lineage abundance in the testing cohort and validated it in a cohort from the GEO dataset. This model remained strongly predictive of prognoses across clinical subgroups. Further analysis revealed that patients with a low-risk score were characterized by B-cell activation and leukocyte migration, which was also confirmed in FFPE specimens by qRT-PCR and immunohistochemistry. Finally, this immune signature was an independent prognostic factor in the composite nomogram of clinical characteristics. CONCLUSIONS: In conclusion, the 13-gene immune signature based on B-cell proportion may serve as a powerful prognostic tool in LUAD.
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Adenocarcinoma del Pulmón/inmunología , Linfocitos B/citología , Perfilación de la Expresión Génica , Neoplasias Pulmonares/inmunología , Linfocitos Infiltrantes de Tumor/citología , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/mortalidad , Adenocarcinoma del Pulmón/terapia , Movimiento Celular , Bases de Datos Genéticas , Femenino , Humanos , Inmunidad Celular , Inmunohistoquímica , Inmunoterapia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/terapia , Masculino , Nomogramas , Adhesión en Parafina , Pronóstico , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Riesgo , Análisis de Secuencia de ARNRESUMEN
Mutation or downregulation of p53 (encoded by TP53) accelerates tumorigenesis and malignant progression in esophageal squamous cell carcinoma (ESCC). However, it is still unknown whether circular RNAs (circRNAs), a novel class of endogenous noncoding RNAs, participate in the regulation of this progress. In this study, we explored the expression profiles of circRNAs in three paired samples of ESCC and identified cCNTNAP3, which is a circRNA that originates from the CNTNAP3 gene transcript and is highly expressed in normal human esophageal tissue. However, we found that the cCNTNAP3 expression level was significantly downregulated in ESCC tissues. In vitro and in vivo studies revealed that cCNTNAP3 inhibited proliferation and increased apoptosis in p53 wild-type ESCC cells, but not in mutant cells. Mechanistically, we found that cCNTNAP3 promotes the expression of p53 by sponging miR-513a-5p. Rescue assay confirmed that the suppressive function of cCNTNAP3 was dependent on miR-513a-5p. We also observed that p53/RBM25 participated in the formation of cCNTNAP3, which implied the existence of a positive feedback loop between cCNTNAP3 and p53. Furthermore, the downregulation of cCNTNAP3 was significantly correlated with later T stage and thus can serve as an independent risk factor for the overall survival of patients with p53 wild-type ESCC. In conclusion, the cCNTNAP3-TP53 positive feedback loop may provide a potential target for the management of ESCC, which also reveals the important role of circRNAs in the regulation of p53.
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Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas de Esófago/metabolismo , Proteínas de la Membrana/genética , Proteínas del Tejido Nervioso/genética , ARN Circular/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Progresión de la Enfermedad , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patología , Carcinoma de Células Escamosas de Esófago/genética , Carcinoma de Células Escamosas de Esófago/patología , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Xenoinjertos , Humanos , Proteínas de la Membrana/metabolismo , Ratones , Ratones Desnudos , Proteínas del Tejido Nervioso/metabolismo , ARN Circular/genética , Transfección , Proteína p53 Supresora de Tumor/genéticaRESUMEN
A generalized superposition method is presented in this paper for free bending vibration analysis of single rectangular plates and assemblies of rectangular plates with arbitrary boundary conditions. The method was developed on the basis of the Levy method, the principle of superposition, and the uniform convergence of half-range Fourier cosine series for continuous functions in a closed interval. Numerical results, obtained using the proposed method for thin isotropic plates and plate assemblies, show that the proposed method is accurate and rapidly convergent. The proposed method can be extended to handle vibration of moderately thick plates made of isotropic and orthotropic materials.
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The performance of low-temperature carbon-based perovskite solar cells (C-PSCs) with high commercial potential was hampered by the inferior interface between the absorber and carbon electrode. In this work, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) was dissolved in an antisolvent for spin-coating perovskite (CH3NH3PbI3, MAPI) films, which was applied to modify both the MAPI films and the interface between the MAPI layer and carbon electrode by gradient engineering. Finally, the C-PSCs based on MAPI-PTAA gradient bulk heterojunction films achieved a power conversion efficiency of 13.0% with an active area of 1 cm2, 26% higher than that of pristine MAPI cells, because of the passivated trap states, accelerated hole extraction, and improved crystalline properties in absorber films.
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Inverted perovskite solar cells (PSCs) have been becoming more and more attractive, owing to their easy-fabrication and suppressed hysteresis, while the ion diffusion between metallic electrode and perovskite layer limit the long-term stability of devices. In this work, we employed a novel polyethylenimine (PEI) modified cross-stacked superaligned carbon nanotube (CSCNT) film in the inverted planar PSCs configurated FTO/NiO x/methylammonium lead tri-iodide (MAPbI3)/6, 6-phenyl C61-butyric acid methyl ester (PCBM)/CSCNT:PEI. By modifying CSCNT with a certain concentration of PEI (0.5 wt %), suitable energy level alignment and promoted interfacial charge transfer have been achieved, leading to a significant enhancement in the photovoltaic performance. As a result, a champion power conversion efficiency (PCE) of â¼11% was obtained with a Voc of 0.95 V, a Jsc of 18.7 mA cm-2, a FF of 0.61 as well as negligible hysteresis. Moreover, CSCNT:PEI based inverted PSCs show superior durability in comparison to the standard silver based devices, remaining over 85% of the initial PCE after 500 h aging under various conditions, including long-term air exposure, thermal, and humid treatment. This work opens up a new avenue of facile modified carbon electrodes for highly stable and hysteresis suppressed PSCs.
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Organic-inorganic hybrid perovskites have been emerging as promising light-harvesting materials for high-efficiency solar cells recently. Compared to solution-based methods, vapor-based deposition technologies are more suitable in preparing compact, uniform, and large-scale perovskite thin films. Here, we utilized flash-evaporation printing (FEP), a laser-induced ultrafast single source evaporation method employing a carbon nanotube evaporator, to fabricate high-quality methylammonium lead iodide perovskite thin films. Stoichiometric films with pure tetragonal perovskite phase can be achieved using a controlled methylammonium iodide to lead iodide ratio in evaporation precursors. The film crystallinity and crystal grain growth could further be promoted after postannealing. Planar solar cells (0.06 cm2) employing these perovskite films exhibit a champion power conversion efficiency (PCE) of 16.8% with insignificant hysteresis, which is among the highest reported PCEs using vapor-based deposition methods. Large-area (1 cm2) devices based on such perovskite films also achieved a stabilized PCE of 11.2%, indicating the feasibility and scalability of our FEP method in fabricating large-area perovskite films for other optoelectronic applications.
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In this study, a facile and effective approach to synthesize high-quality perovskite-quantum dots (QDs) hybrid film is demonstrated, which dramatically improves the photovoltaic performance of a perovskite solar cell (PSC). Adding PbS QDs into CH3 NH3 PbI3 (MAPbI3 ) precursor to form a QD-in-perovskite structure is found to be beneficial for the crystallization of perovskite, revealed by enlarged grain size, reduced fragmentized grains, enhanced characteristic peak intensity, and large percentage of (220) plane in X-ray diffraction patterns. The hybrid film also shows higher carrier mobility, as evidenced by Hall Effect measurement. By taking all these advantages, the PSC based on MAPbI3 -PbS hybrid film leads to an improvement in power conversion efficiency by 14% compared to that based on pure perovskite, primarily ascribed to higher current density and fill factor (FF). Ultimately, an efficiency reaching up to 18.6% and a FF of over ≈0.77 are achieved based on the PSC with hybrid film. Such a simple hybridizing technique opens up a promising method to improve the performance of PSCs, and has strong potential to be applied to prepare other hybrid composite materials.
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Significant efforts have been devoted to enhancing both the performance and long-term stability of lead halide perovskite solar cells (PSCs) to promote their practical application. In this context, a self-assembled monolayer composed of a dye molecule is demonstrated for the first time to be efficient in passivating the surface of the hole transport layer, NiO x, in the p-i-n PSCs through multiple functions, including the minimization of energy-level offset, reducing surface trap states, and enhancing wetting between NiO x and perovskite layers coupled with increasing perovskite crystallinity. Consequently, the dye monolayer has sufficiently improved the hole extraction efficiency and suppressed the charge recombination, validated by steady and transient photoluminescence measurements and the electrochemical impedance analysis. Concurrently, a mixed layer of BaSnO3 nanoparticles and [6,6]-phenyl-C61-butyric acid methyl (PCBM) (barium stannate (BSO)/PCBM) was exploited as an efficient electron transport layer, resulting in superior electron transport properties and correspondingly excellent device stability. By incorporating these bifacial modifications, the device performance of the inverted PSC was propelled to 16.2%, compared with 14.0% for that without any interfacial and compositional engineering. Benefiting from the excellent crystallinity of the perovskite through dye passivation and the blocking of moisture, oxygen, and ion migration by using the hybrid BSO/PCBM layer, over 90% of the initial power conversion efficiency has been preserved for the device after exposure to ambient air for 650 h.
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Electron-extraction layer (EEL) plays a critical role in determining the charge extraction and the power conversion efficiencies of the organometal-halide perovskite solar cells (PSCs). In this work, Ti-Fe-O ternary oxides were first developed to work as an efficient EEL in planar PSC. Compared with the widely used TiOx and the pure FeOx, the ternary composites show superior properties in multiple aspects including the excellent stability of the precursor solution, good coverage on the substrates, outstanding electrical properties, and suitable energy levels. By varying the Fe content from 0 to 100% in the Ti-Fe-O composites, the conductivity of the resultant compact layer was markedly improved, confirmed by consistent results from the conductive atomic force microscopy and the linear sweep voltammetry measurements. Meanwhile, the compositional engineering tunes the energy level alignment of the Ti-Fe-O EEL/CH3NH3PbI3 interface to a region that is favorable for obtaining excellent charge-extraction property. The combinational advantages of the Ti-Fe-O composites significantly improved the photovoltaic performance of the as-prepared solar cells. An increase of over 20% in the short-circuit current (JSC) density has been achieved due to a modified EEL conductivity and energy alignment with the perovskite layer. The reduction in the surface recombination and enhancement of the charge collection efficiency also result in about 15% increase in the fill factor. Notably, the device also showed remarkably alleviated hysteresis behavior, revealing a prominently inhibited surface recombination.
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The combination of perovskite solar cells and quantum dot solar cells has significant potential due to the complementary nature of the two constituent materials. In this study, solar cells (SCs) with a hybrid CH3 NH3 PbI3 /SnS quantum dots (QDs) absorber layer are fabricated by a facile and universal in situ crystallization method, enabling easy embedding of the QDs in perovskite layer. Compared with SCs based on CH3 NH3 PbI3 , SCs using CH3 NH3 PbI3 /SnS QDs hybrid films as absorber achieves a 25% enhancement in efficiency, giving rise to an efficiency of 16.8%. The performance improvement can be attributed to the improved crystallinity of the absorber, enhanced photo-induced carriers' separation and transport within the absorber layer, and improved incident light utilization. The generality of the methods used in this work paves a universal pathway for preparing other perovskite/QDs hybrid materials and the synthesis of entire nontoxic perovskite/QDs hybrid structure.
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Although the two-step deposition (TSD) method is widely adopted for the high performance perovskite solar cells (PSCs), the CH3NH3PbI3 perovskite crystal growth mechanism during the TSD process and the photo-generated charge recombination dynamics in the mesoporous-TiO2 (mp-TiO2)/CH3NH3PbI3/hole transporting material (HTM) system remains unexploited. Herein, we modified the concentration of PbI2 (C(PbI2)) solution to control the perovskite crystal properties, and observed an abnormal CH3NH3PbI3 grain growth phenomenon atop mesoporous TiO2 film. To illustrate this abnormal grain growth mechanism, we propose that a grain ripening process is taking place during the transformation from PbI2 to CH3NH3PbI3, and discuss the PbI2 nuclei morphology, perovskite grain growing stage, as well as Pb:I atomic ratio difference among CH3NH3PbI3 grains with different morphology. These C(PbI2)-dependent perovskite morphologies resulted in varied charge carrier transfer properties throughout the mp-TiO2/CH3NH3PbI3/HTM hybrid, as illustrated by photoluminescence measurement. Furthermore, the effect of CH3NH3PbI3 morphology on light absorption and interfacial properties is investigated and correlated with the photovoltaic performance of PSCs.
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NiOx is a promising hole-transporting material for perovskite solar cells due to its high hole mobility, good stability, and easy processability. In this work, we employed a simple solution-processed NiOx film as the hole-transporting layer in perovskite solar cells. When the thickness of the perovskite layer increased from 270 to 380 nm, the light absorption and photogenerated carrier density were enhanced and the transporting distance of electron and hole would also increase at the same time, resulting in a large charge transfer resistance and a long hole-extracted process in the device, characterized by the UV-vis, photoluminescence, and electrochemical impedance spectroscopy spectra. Combining both of these factors, an optimal thickness of 334.2 nm was prepared with the perovskite precursor concentration of 1.35 M. Moreover, the optimal device fabrication conditions were further achieved by optimizing the thickness of NiOx hole-transporting layer and PCBM electron selective layer. As a result, the best power conversion efficiency of 15.71% was obtained with a Jsc of 20.51 mA·cm-2, a Voc of 988 mV, and a FF of 77.51% with almost no hysteresis. A stable efficiency of 15.10% was caught at the maximum power point. This work provides a promising route to achieve higher efficiency perovskite solar cells based on NiO or other inorganic hole-transporting materials.
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Thermal luminescence quenching behavior of a phosphor is essential for application in phosphor converted white light emitting diodes (pc-WLEDs) because the phosphor layer can be heated up to 473K in a working high power WLEDs. Here, we have confirmed indeed a red luminescence of Mn(4+) substituting for calcium sites rather than tetrahedral aluminum sites in CaAl(4)O(7):Mn which can be synthesized in pure phase even with boron acid as flux, and examined the low and high temperature luminescent properties in the range of 10 to 500K. We have revealed as well as thermal quenching mechanism that distorted octahedral Mn(4+) sites suffer severe thermal quenching. This work, thus, hints a strategy to find a new Mn(4+) phosphor with better resistance to thermal impact in the future.