X‐ray detectors are widely utilized in medical diagnostics and nondestructive product inspection. Halide perovskites are recently demonstrated as excellent candidates for direct X‐ray detection. ...However, it is still challenging to obtain high quality perovskites with millimeter‐thick over a large area for high performance, stable X‐ray detectors. Here, methylammonium bismuth iodide (MA3Bi2I9) polycrystalline pellets (PPs) are developed by a robust, cost effective, and scalable cold isostatic‐pressing for fabricating X‐ray detectors with low limit of detection (LoD) and superior operational stability. The MA3Bi2I9‐PPs possess a high resistivity of 2.28 × 1011 Ω cm and low dark carrier concentration of ≈107 cm−3, and balanced mobility of ≈2 cm2 V−1 s−1 for electrons and holes. These merits enable a sensitivity of 563 μC Gyair−1 cm−2, a detection efficiency of 28.8%, and an LoD of 9.3 nGyair s−1 for MA3Bi2I9‐PPs detectors, and the LoD is much lower than the dose rate required for X‐ray diagnostics used currently (5.5 μGyair s−1). In addition, the MA3Bi2I9‐PPs detectors work stably under high working bias field up to 2000 V cm−1 after sensing an integrated dose >320 Gyair with continuous X‐ray radiation, demonstrating its competitive advantage in practical application. These findings provide an approach to explore a new generation of low LoD, stable and green X‐ray detectors based on MA3Bi2I9‐PPs.
MA3Bi2I9 polycrystalline pellets (PPs) are fabricated by the robust, cost‐effective, and scalable cold isostatic‐pressing approach, and X‐ray detectors based on MA3Bi2I9‐PPs reach a limit of detection (LoD) of 9.3 nGyair s−1. The low LoD of the X‐ray detectors can obviously decrease the radiation dose used, thereby reducing health risks in medical diagnostics and security screening.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The organic–inorganic halide CH3NH3PbI3 (MAPbI3) has been the most commonly used light absorber layer of perovskite solar cells (PSCs); however, solution‐processed MAPbI3 films usually suffer from ...random crystal orientation and high trap density, resulting in inferior power conversion efficiency (PCE) with open circuit voltage (Voc) being typically below 1.2 V for PSC devices. Herein, for the first time an imidazole sulfonate zwitterion, 4‐(1H‐imidazol‐3‐ium‐3‐yl)butane‐1‐sulfonate (IMS), is applied as a bifunctional additive in regular‐structure planar heterojunction PSC devices to regulate the crystal orientation, yielding highly ordered MAPbI3 film and passivating the trap states of the film. Such a dual effect of IMS is fulfilled via coordination interactions between the sulfonate moiety of IMS with the Pb2+ ion and the electrostatic interaction between the imidazole of IMS with the I– ion of MAPbI3. As a result, under a optimized IMS doping ratio of 0.5 wt%, the PSC device exhibits a significant increase in PCE from 18.77% to 20.84%, with suppressed current–voltage hysteresis and promoted ambient stability. Moreover, a high Voc of 1.208 V is achieved under a higher IMS doping ratio of 1.2 wt%, which is the highest Voc for regular‐structure MAPbI3 planar PSC devices based on TiO2 electron transport layer.
A bifunctional zwitterion additive affords efficiency enhancement of perovskite solar cells: an imidazole sulfonate zwitterion is doped into a CH3NH3PbI3 precursor solution as a bifunctional additive, enabling regulation of crystalline grain orientation and passivation of trap states. As a result, a significant efficiency enhancement and a high open circuit voltage (Voc) of 1.208 V are achieved.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
In the last few years, organometal halide perovskites (OHPs) have emerged as a promising candidate for photovoltaic (PV) applications. A certified efficiency as high as 23.7% has been achieved, which ...is comparable with most of the well‐established PV technologies. Their good solubility due to the ionic nature enables versatile low‐temperature solution processes, including blade coating, slot‐die coating, etc., most of which are scalable and compatible with roll‐to‐roll large‐scale manufacturing processes. The low cost, high efficiency, and facile processable features make perovskite solar cells (PSCs) a very competitive PV technology. Despite the great progress, long‐term durability concerns, toxicity issues of both materials and manufacturing process, and lack of robust high‐throughput production technology for fabricating efficient large‐area modules are major obstacles toward commercialization. In this review, the recent progress of commercially available process of PSCs is surveyed, the underlying determinants for upscaling high‐quality PSCs from hydrodynamic characteristics and crystallization thermodynamic mechanism are identified, the influence of external stress factors on stability of PSCs and intrinsic instability mechanism in OHPs themselves is revealed, and the environmental impact and sustainable development of PSC technology are analyzed. Strategies and opportunities for large‐scale production of PSCs are suggested to promote the development of PSCs toward commercialization.
Perovskite solar cells (PSCs) have emerged as a promising candidate for photovoltaic applications. This review summarizes the recent progress and discusses the obstacles for PSCs toward industrial production, including upscaling of high‐quality perovskites for efficient PSC modules, stability issue of PSCs, Pb substitution, and greener manufacturing process, which can promote the development of PSCs toward commercialization.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Podlike nitrogen‐doped carbon nanotubes encapsulating FeNi alloy nanoparticles (Pod(N)‐FeNi) were prepared by the direct pyrolysis of organometallic precursors. Cyclic voltammetry (CV), ...electrochemical impedance spectroscopy (EIS), and Tafel polarization measurements revealed their excellent electrocatalytic activities in the I−/I3− redox reaction of dye‐sensitized solar cells (DSSCs). This is suggested to arise from the modification of the surface electronic properties of the carbon by the encapsulated metal alloy nanoparticles (NPs). Sequential scanning with EIS and CV further showed the high electrochemical stability of the Pod(N)‐FeNi composite. DSSCs with Pod(N)‐FeNi as the counter electrode (CE) presented a power conversion efficiency of 8.82 %, which is superior to that of the control device with sputtered Pt as the CE. The Pod(N)‐FeNi composite thus shows promise as an environmentally friendly, low‐cost, and highly efficient CE material for DSSCs.
The direct pyrolysis of organometallic precursors was used to prepare podlike nitrogen‐doped carbon nanotubes encapsulating FeNi alloy nanoparticles (Pod(N)‐FeNi), which exhibited high electrocatalytic activity in the I3−/I− redox reaction and excellent electrochemical stability. The photovoltaic performance of dye‐sensitized solar cells made with the Pod(N)‐FeNi counter electrode was similar to that having a Pt counter electrode.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The unstable feature of the widely employed organic hole‐transporting materials (HTMs) (e.g., spiro‐MeOTAD) significantly limits the practical application of perovskite solar cells (PSCs). Therefore, ...it is desirable to design new structured PSCs with stable HTMs presenting excellent carrier extraction and transfer properties. This work demonstrates a new inverted PSC configuration. The new PSC has a graded band alignment and bilayered inorganic HTMs (i.e., compact NiOx and mesoporous CuGaO2). In comparison with planar‐structured PSCs, the mesoporous CuGaO2 can effectively extract holes from perovskite due to the increased contact area of the perovskite/HTM. The graded energy alignment constructed in the ultrathin compact NiOx, mesoporous CuGaO2, and perovskite can facilitate carrier transfer and depress charge recombination. As a result, the champion device based on the newly designed mesoscopic PSCs yields a stabilized efficiency of ≈20%, which is considered one of the best results for inverted PSCs with inorganic HTMs. Additionally, the unencapsulated PSC device retains more than 80% of its original efficiency when subjected to thermal aging at 85 °C for 1000 h in a nitrogen atmosphere, thus demonstrating superior thermal stability of the device. This study may pave a new avenue to rational design of highly efficient and stable PSCs.
A graded bilayered inorganic hole‐transporting layer (including compact NiOx and mesoporous CuGaO2) is developed for inverted perovskite solar cells. The resulting devices demonstrate both high efficiency, with the champion one giving a stabilized efficiency of ≈20% and superior thermal stability with >80% of the initial efficiency being retained subject to 1000 hours' thermal aging at 85 °C.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Background
Molecular subtyping of triple‐negative breast cancers (TNBCs) via gene expression profiling is essential for understanding the molecular essence of this heterogeneous disease and for ...guiding individualized treatment. We aim to devise a clinically practical method based on immunohistochemistry (IHC) for the molecular subtyping of TNBCs.
Materials and Methods
By analyzing the RNA sequencing data on TNBCs from Fudan University Shanghai Cancer Center (FUSCC) (n = 360) and The Cancer Genome Atlas data set (n = 158), we determined markers that can identify specific molecular subtypes. We performed immunohistochemical staining on tumor sections of 210 TNBCs from FUSCC, established an IHC‐based classifier, and applied it to another two cohorts (n = 183 and 214).
Results
We selected androgen receptor (AR), CD8, FOXC1, and DCLK1 as immunohistochemical markers and classified TNBCs into five subtypes based on the staining results: (a) IHC‐based luminal androgen receptor (IHC‐LAR; AR‐positive +), (b) IHC‐based immunomodulatory (IHC‐IM; AR‐negative −, CD8+), (c) IHC‐based basal‐like immune‐suppressed (IHC‐BLIS; AR−, CD8−, FOXC1+), (d) IHC‐based mesenchymal (IHC‐MES; AR−, CD8−, FOXC1−, DCLK1+), and (e) IHC‐based unclassifiable (AR−, CD8−, FOXC1−, DCLK1−). The κ statistic indicated substantial agreement between the IHC‐based classification and mRNA‐based classification. Multivariate survival analysis suggested that our IHC‐based classification was an independent prognostic factor for relapse‐free survival. Transcriptomic data and pathological observations implied potential treatment strategies for different subtypes. The IHC‐LAR subtype showed relative activation of HER2 pathway. The IHC‐IM subtype tended to exhibit an immune‐inflamed phenotype characterized by the infiltration of CD8+ T cells into tumor parenchyma. The IHC‐BLIS subtype showed high expression of a VEGF signature. The IHC‐MES subtype displayed activation of JAK/STAT3 signaling pathway.
Conclusion
We developed an IHC‐based approach to classify TNBCs into molecular subtypes. This IHC‐based classification can provide additional information for prognostic evaluation. It allows for subgrouping of TNBC patients in clinical trials and evaluating the efficacy of targeted therapies within certain subtypes.
Implications for Practice
An immunohistochemistry (IHC)‐based classification approach was developed for triple‐negative breast cancer (TNBC), which exhibited substantial agreement with the mRNA expression‐based classification. This IHC‐based classification (a) allows for subgrouping of TNBC patients in large clinical trials and evaluating the efficacy of targeted therapies within certain subtypes, (b) will contribute to the practical application of subtype‐specific treatment for patients with TNBC, and (c) can provide additional information beyond traditional prognostic factors in relapse prediction.
This article describes an immunohistochemistry‐based approach to classification of triple‐negative breast cancers into molecular subtypes for purposes of the translation of TNBC molecular classification into clinical practice.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Photoreactive olefinic species are incorporated into a metal–organic framework (MOF), Zn(bdc)(3‐F‐spy) (1). Single crystals of 1 are shown to undergo three types of photomechanical macroscopic ...deformation upon illumination by UV light. To demonstrate the practical potential of this system, the inclusion of 1 in a PVA (polyvinyl alcohol) composite membrane, by exploiting hydrogen‐bonding interactions, is presented. Using this composite membrane, the amplification of mechanical stress to achieve macroscopic actuation behavior is demonstrated. These results pave the way for the generation of MOF‐based soft photoactuators that produce clearly defined mechanical responses upon irradiation with light. Such systems are anticipated to have considerable potential in photomechanical energy harvesting and conversion systems.
A self‐assembly strategy for the fabrication of a hierarchical photoactuator system in which a photoresponsive moiety is incorporated into a MOF crystal. A photoactuation system was successfully fabricated that involves a MOF‐PVA composite membrane, which exhibits a macroscopic response upon exposure to UV light irradiation.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Understanding the dynamics and underlying mechanism of carbon exchange between terrestrial ecosystems and the atmosphere is one of the key issues in global change research. In this study, we ...quantified the carbon fluxes in different terrestrial ecosystems in China, and analyzed their spatial variation and environmental drivers based on the long‐term observation data of ChinaFLUX sites and the published data from other flux sites in China. The results indicate that gross ecosystem productivity (GEP), ecosystem respiration (ER), and net ecosystem productivity (NEP) of terrestrial ecosystems in China showed a significantly latitudinal pattern, declining linearly with the increase of latitude. However, GEP, ER, and NEP did not present a clear longitudinal pattern. The carbon sink functional areas of terrestrial ecosystems in China were mainly located in the subtropical and temperate forests, coastal wetlands in eastern China, the temperate meadow steppe in the northeast China, and the alpine meadow in eastern edge of Qinghai‐Tibetan Plateau. The forest ecosystems had stronger carbon sink than grassland ecosystems. The spatial patterns of GEP and ER in China were mainly determined by mean annual precipitation (MAP) and mean annual temperature (MAT), whereas the spatial variation in NEP was largely explained by MAT. The combined effects of MAT and MAP explained 79%, 62%, and 66% of the spatial variations in GEP, ER, and NEP, respectively. The GEP, ER, and NEP in different ecosystems in China exhibited ‘positive coupling correlation’ in their spatial patterns. Both ER and NEP were significantly correlated with GEP, with 68% of the per‐unit GEP contributed to ER and 29% to NEP. MAT and MAP affected the spatial patterns of ER and NEP mainly by their direct effects on the spatial pattern of GEP.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Antimony is an attractive anode material for sodium‐ion batteries (SIBs) owing to its high theoretical capacity and appropriate sodiation potential. However, its practical application is severely ...impeded by its poor cycling stability caused by dramatic volumetric variations during sodium uptake and release processes. Here, to circumvent this obstacle, Sb@C@TiO2 triple‐shell nanoboxes (TSNBs) are synthesized through a template‐engaged galvanic replacement approach. The TSNB structure consists of an inner Sb hollow nanobox protected by a conductive carbon middle shell and a TiO2‐nanosheet‐constructed outer shell. This structure offers dual protection to the inner Sb and enough room to accommodate volume expansion, thus promoting the structural integrity of the electrode and the formation of a stable solid–electrolyte interface film. Benefiting from the rational structural design and synergistic effects of Sb, carbon, and TiO2, the Sb@C@TiO2 electrode exhibits superior rate performance (212 mAh g−1 at 10 A g−1) and outstanding long‐term cycling stability (193 mAh g−1 at 1 A g−1 after 4000 cycles). Moreover, a full cell assembled with a configuration of Sb@C@TiO2//Na3(VOPO4)2F displays a high output voltage of 2.8 V and a high energy density of 179 Wh kg−1, revealing the great promise of Sb@C@TiO2 TSNBs as the electrode in SIBs.
Sb@C@TiO2 triple‐shell nanoboxes (TSNBs) composed of an inner Sb hollow nanobox protected by a conductive carbon middle shell and a TiO2‐nanosheet‐constructed outer shell are synthesized through a template‐engaged galvanic replacement approach. Benefiting from the rational structural design,the Sb@C@TiO2 TSNBs exhibit enhanced sodium storage performance in terms of superior rate performance and outstanding long‐term cycling stability.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
One‐dimensional (1D) nanostructured oxides are proposed as excellent electron transport materials (ETMs) for perovskite solar cells (PSCs); however, experimental evidence is lacking. A facile ...hydrothermal approach was employed to grow highly oriented anatase TiO2 nanopyramid arrays and demonstrate their application in PSCs. The oriented TiO2 nanopyramid arrays afford sufficient contact area for electron extraction and increase light transmission. Moreover, the nanopyramid array/perovskite system exhibits an oriented electric field that can increase charge separation and accelerate charge transport, thereby suppressing charge recombination. The anatase TiO2 nanopyramid array‐based PSCs deliver a champion power conversion efficiency of approximately 22.5 %, which is the highest power conversion efficiency reported to date for PSCs consisting of 1D ETMs. This work demonstrates that the rational design of 1D ETMs can achieve PSCs that perform as well as typical mesoscopic and planar PSCs.
Nanopyramid arrays of 1D highly oriented anatase TiO2 present an oriented electric field distribution, which is favorable for charge separation and transport. An impressive power conversion efficiency of approximately 22.5 % was achieved, which is the highest efficiency reported for perovskite solar cells consisting of 1D electron transport materials to date.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
PDF
