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- 摘要
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- 实验方案
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Electron Transporting Bilayer of SnO <sub/>2</sub> and TiO <sub/>2</sub> Nanocolloid Enables Highly Efficient Planar Perovskite Solar Cells
摘要： Here, we applied the commercially accessible SnO2 and home-made TiO2 NPs as a combined electron transporting bilayer (ETBL) to achieve a highly efficient planar perovskite solar cell (PSC). The formed cascade-aligned energy levels from the proper stacking of SnO2 and TiO2 layers and the excellent defect-passivation ability of TiO2, SnO2/TiO2 ETBLs effectively reduced energy loss and inhibited defects formation both at the ETL/perovskite interface and within the bulk of perovskite layer as revealed by a comprehensive analysis of photoelectric characteristic analysis, including ultraviolet photoelectron spectroscopy, photoluminescence and electrochemical impedance spectroscopy. Consequently, the PSC devices acquired a high PCE of 20.50% with a Voc of 1.10 V, a Jsc of 24.2 mA/cm2 and an FF of 77%, which are superior to the values of the control device based on single SnO2 layer with a PCE of 18.09% (a 13.3% boosting on PCE). Moreover, there was no degradation after 49 days, indicating the great stability after adding TiO2 layer. Our work demonstrates that the cascaded alignment of energy levels between the electrode and perovskite layer by ETBLs could be an effective approach to improve the photovoltaic performance of the PSCs with excellent long-term stability.
关键词： electron transporting bilayer,perovskite solar cells,SnO2 nanoparticles,TiO2 nanoparticles,cascade-aligned energy level
更新于2025-09-11 14:15:04
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Improved Interface Charge Extraction by Double Electron Transport Layers for High‐Efficient Planar Perovskite Solar Cells
摘要： Charge extraction by electron transport layers (ETLs) plays a vital role in improving the performance of perovskite solar cells (PSCs). Here, PSCs with four different types of ETLs, such as SnO2, amorphous-Zn2SnO4 (am-ZTO), am-ZTO/SnO2, and SnO2/am-ZTO, are successfully synthesized. The interface recombination behavior and the charge transport properties of the devices affected by four types of ETLs are systematically investigated. For dual am-ZTO/SnO2 ETLs, compact am-ZTO ETL prepared by the pulsed laser deposition method provides a dense physical contact with FTO than the spin coating films, decreasing leakage current and improving charge collection at the interface of ETL/FTO. Moreover, dual am-ZTO/SnO2 ETLs lead to large free energy difference (ΔG), improving electron injection from perovskite to ETLs. One additional electron pathway from perovskite to am-ZTO is formed, which can also improve electron injection efficiency. A power conversion efficiency of 20.04% and a stabilized efficiency of 19.17% are achieved for the device based on dual am-ZTO/SnO2 ETLs. Most importantly, the devices are fabricated at a low temperature of 150 °C, which offers a potential method for large-scale production of PSCs, and paves the way for the development of flexible PSCs. It is believed that this work provides a strategy to design ETLs via controlling ΔG and interface contact to improve the performance of PSCs.
关键词： amorphous-Zn2SnO4/SnO2,charge transport,perovskite solar cells,interface recombination
更新于2025-09-11 14:15:04
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Spray-coated monodispersed SnO2 microsphere films as scaffold layers for efficient mesoscopic perovskite solar cells
摘要： Mesoporous SnO2 microspheres are a class of promising electron transport materials for mesoscopic perovskite solar cells, but a smooth and dense film as requested by electron transport layer is difficult to realize using the microspheres. Here, a series of monodispersed SnO2 microspheres with high specific surface area and good crystallinity are synthesized via a surfactant-free solvothermal method. These SnO2 microspheres showing small diameters of about 75, 110 and 200 nm with narrow size distribution are achieved by precisely controlling the crystal growth process. They are suitable for constructing the electron transport layers whose thickness is only about hundreds nanometers. Besides, as the microspheres easily slip off from the substrate during the conventional spin coating process, the spray coating method is exploited to prepare high quality electron transport layers. As a result, a power conversion efficiency of 16.85% is yielded by using the 75 nm sized SnO2 microspheres as the electron transport layers. This high power conversion efficiency is attributed to the fast electron transport and inhibited charge recombination. To further improve the charge transfer between the electron transport layer and perovskite layer, graphene quantum dots are added into the SnO2 microspheres, and a best efficiency of 17.08% is obtained.
关键词： Monodispersed SnO2 microspheres,Electron transport layer,Spray coating,Perovskite solar cells
更新于2025-09-11 14:15:04
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Burrs-Shelled SnO2@Al2O3 Nanocables for Detection of 3-Hydroxy-2-Butanone Biomarkers
摘要： Detection of 3-hydroxy-2-butanone (3H-2B) biomarker is a newly emerging and feasible way to monitor Listeria monocytogenes (LMs). Although progress has been made in gas-sensing methodology, the long-term adsorption of the intermediate products of the reaction onto the sensing materials leads to a decrease in stability and selectivity. Herein, we report highly selective and stable 3H-2B sensors, which are developed from a core-shell structure of tin oxide nanowire coated with alumina (SnO2@Al2O3 NCBs), via combining AAO template-confined electrodeposition and wet-chemical etching. As-built sensors exhibit high sensitivity of Ra/Rg = 43.3 to 5 ppm 3H-2B at 120 oC, which is around 6 ~ 40 times against other interfering gases. Also, our sensors exhibit excellent stability with 42 days’ evaluation. Furthermore, the sensors can detect as low as 0.1 ppm 3H-2B (Ra/Rg = 2.4; 120 oC), and the sensitivity reach Ra/Rg = 27.2 at 50 oC. Our SnO2@Al2O3 NCBs sensors are endowed with ppb-level detection limit, excellent selectivity and stability at low temperature, which is of great potential in future detection of LMs.
关键词： SnO2@Al2O3 nanocables,3-hydroxy-2-butanone,selectivity and stability,sensor,AAO template
更新于2025-09-11 14:15:04
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Effect of the Substrate Temperature on the Properties of SnO<sub>2</sub> Thin Films Prepared by Ultrasonic Spray for Solar Cells Applications
摘要： Structural, optical properties of SnO2 thin films deposited by spray ultrasonic technique were investigated by varying substrate temperature. The structural characterization of the films was analyzed via X-ray diffraction (XRD) technique and transmission electron microscopy (TEM). These studies indicated that the layers were polycrystalline. Films surface morphologies were studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Optical absorption spectrum was recorded using the UV-VIS-NIR spectroscopy and the films were found to be transparent. The optical transmittance varied with substrate temperature from 60–80% over a wide range of wavelength. Optical measurements showed that the layers had a relatively high absorption coefficient of 105 cm?1. A shift in the absorption edge was observed and the films exhibited direct transitions with band gap energies ranging from 3.85 to 3.94 eV.
关键词： transparent and conductive tin dioxide,SnO2 thin films,spray ultrasonic technique,substrate temperature
更新于2025-09-11 14:15:04
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3D Multi-Branched SnO2 Semiconductor Nanostructures as Optical Waveguides
摘要： Nanostructures with complex geometry have gathered interest recently due to some unusual and exotic properties associated with both their shape and material. 3D multi-branched SnO2 one-dimensional nanostructrures, characterized by a “node”—i.e., the location where two or more branches originate, are the ideal platform to distribute signals of di?erent natures. In this work, we study how this particular geometrical con?guration a?ects light propagation when a light source (i.e., laser) is focused onto it. Combining scanning electron microscopy (SEM) and optical analysis along with Raman and Rayleigh scattering upon illumination, we were able to understand, in more detail, the mechanism behind the light-coupling occurring at the node. Our experimental ?ndings show that multi-branched semiconductor 1D structures have great potential as optically active nanostructures with waveguiding properties, thus paving the way for their application as novel building blocks for optical communication networks.
关键词： SnO2,waveguiding e?ect in nanostructures,3D multi-branched nanostructures,nanowires,light scattering,tin oxide nanostructure,nano-optics
更新于2025-09-11 14:15:04
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Sensitive Detection of Prostate Specific Antigen Based on Copper Ions Doped Ag-Au Nanospheres Labeled Immunosensor
摘要： A sandwich-type electrochemical immunosensor was designed for quantitative detection of prostate speci?c antigen (PSA). Gold-platinum bimetallic functionalized tin oxide graphene (GS-SnO2-Au@Pt) has a large speci?c surface area, good conductivity and biocompatibility, which was used as the sensing interface to capture PSA coating antibody (Ab1). The copper ions doped Ag-Au nanospheres (Cu2+@Ag-Au) was prepared and used as a label of PSA labeling antibody (Ab2), which generated high intensive electrochemical redox signal based on the reduction reaction of Cu2+. The L-cysteine was applied as a bridge to connect Au nanoparticles (NPs) and Ag NPs, and to keep the nanosized gap between Au nuclear and Ag shell. This structure not only makes full advantage of space effect to load more Ag NPs but also increases the speci?c surface area for loaded more Cu2+. The proposed immunosensor with a wide range (10 pg mL?1 to 100 ng mL?1) and a low detection limit (3.84 pg mL?1) shows excellent performance in the detection of PSA. The results indicate that proposed immunosensor provides a promising application for the quantitative detection of biomolecules in serum samples.
关键词： Cu2+@Ag-Au,prostate speci?c antigen,GS-SnO2-Au@Pt,electrochemical immunosensor,signal amplification
更新于2025-09-11 14:15:04
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Red‐Carbon‐Quantum‐Dot‐Doped SnO <sub/>2</sub> Composite with Enhanced Electron Mobility for Efficient and Stable Perovskite Solar Cells
摘要： An efficient electron transport layer (ETL) plays a key role in promoting carrier separation and electron extraction in planar perovskite solar cells (PSCs). An effective composite ETL is fabricated using carboxylic-acid- and hydroxyl-rich red-carbon quantum dots (RCQs) to dope low-temperature solution-processed SnO2, which dramatically increases its electron mobility by ≈20 times from 9.32 × 10?4 to 1.73 × 10?2 cm2 V?1 s?1. The mobility achieved is one of the highest reported electron mobilities for modified SnO2. Fabricated planar PSCs based on this novel SnO2 ETL demonstrate an outstanding improvement in efficiency from 19.15% for PSCs without RCQs up to 22.77% and have enhanced long-term stability against humidity, preserving over 95% of the initial efficiency after 1000 h under 40–60% humidity at 25 °C. These significant achievements are solely attributed to the excellent electron mobility of the novel ETL, which is also proven to help the passivation of traps/defects at the ETL/perovskite interface and to promote the formation of highly crystallized perovskite, with an enhanced phase purity and uniformity over a large area. These results demonstrate that inexpensive RCQs are simple but excellent additives for producing efficient ETLs in stable high-performance PSCs as well as other perovskite-based optoelectronics.
关键词： electron transport layers,SnO2,planar perovskite solar cells,synchrotron-based GIXRD,red-carbon quantum dots
更新于2025-09-11 14:15:04
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Constructing hierarchical SnO2 nanofiber/nanosheets for efficient formaldehyde detection
摘要： SnO2 nanofiber/nanosheets with hierarchical nanostructures were successfully synthesized via a facile hydrothermal method by using hollow SnO2 nanofibers as the backbone. The microstructure, morphology, chemical composition, oxidation states and surface areas of SnO2 nanofibers, SnO2 nanofiber/nanosheets and SnO2 nanosheets were comparatively studied by X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET). The characterization results indicated that the hierarchical SnO2 nanofiber/nanosheets were constructed by nanosheets arrays uniform growth on the surface of nanofibers. Sensing performances of SnO2-based nanomaterials were investigated utilizing formaldehyde (HCHO) as a target gas. Compared to SnO2 nanofibers, nanosheets and the physical mixture of nanofibers and nanosheets, the gas sensor based on SnO2 nanofiber/nanosheets exhibited better response, more excellent selectivity, transient response and trace detection ability to HCHO gas. The response (Ra/Rg) of the gas sensor is 57 toward 100 ppm HCHO at 120 °C, which is about 300% and 200% higher than that of pure SnO2 nanofibers sensors and SnO2 nanosheets sensors, respectively. Furthermore, the sensor has an excellent response/recovery performance with 4.7 s and 11.6 s for detecting 100 ppm HCHO. Both the growth process and the gas sensing mechanism of SnO2 hierarchical nanostructures were discussed. Successful preparation of SnO2 nanofiber/nanosheets is attributed to uniform decoration of seeds on the nanofibers and suitable growth conditions of nanosheets. Enhanced sensing performance mainly result from the synergistic effect of nanofibers and nanosheets, hierarchical structures and larger specific surface areas. The synthetic strategy can also be applied in preparing hierarchical materials of different constituent materials.
关键词： Homogeneous materials,SnO2 nanofiber/nanosheets,Formaldehyde gas sensors,Hierarchical structure
更新于2025-09-10 09:29:36
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Improved photoelectric properties of BiOBr nanoplates by co-modifying SnO2 and Ag to promote photoelectrons trapped by adsorbed O2; 通过SnO2和Ag共修饰促进光生电子捕获氧气改善BiOBr纳米盘的光电特性;
摘要： It is highly desired to improve the photoelectric property of nanosized BiOBr by promoting the photogenerated charge transfer and separation. Herein, SnO2 and Ag co-modified BiOBr nanocomposites (Ag-SO-BOB) have been prepared through a simple one-pot hydrothermal method. Surface photovoltage response of BiOBr nanoplates has 4.1-time enhancement after being modified with SnO2 nanoparticles. Transient-state surface photovoltage (TS-SPV) and the atmosphere-controlled steady-state surface photovoltage spectroscopy (AC-SPS) confirmed that this exceptional enhancement of the photovoltage response can be ascribed to the coupled SnO2 acting as platform for accepting the photoelectrons from BiOBr so as to prolong the lifetime and enhance charge separation. Remarkably, the surface photovoltage response can be further enhanced by synchronously introducing Ag nanoparticles, which is up to 15.4-times enhancement compared with bulk BiOBr nanoplates. The enhancement can be attributed to the improved O2 adsorption by introducing Ag to further enhance charge separation. Finally, the synergistic effect of SnO2 and Ag co-modification enhances the surface photovoltage response due to the enhanced charge separation and promoted O2 adsorption, which is also confirmed through photoelectrochemistry and photocatalytic experiment.
关键词： surface photovoltage response,O2 adsorption,charge separation,photoelectron trapping,Ag-SnO2-BiOBr
更新于2025-09-10 09:29:36